INDUSTRIAL METALS · MATERIAL SOURCING · FABRICATION
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STEEL IMPEX INDIA
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+91 95946 66986 · sanjay@steelimp.com · steelimp.com
GSTIN 27ADJPJ5621J1ZF · Reference copy · 11 November 2026

STEEL IMPEX INDIA · ENGINEERING REFERENCE

SS Fastener Grades & Dimensions | Bolts, Nuts & Screws

Find bolts, nuts, screws, studs and washers by name, material designation or standard. Keep the alloy, mechanical property class, product dimensions, pitch, coating and inspection requirements separate when preparing an order.

Compiled by Steel Impex India · Source review · Values match app v1.5.11

Open reference Common questions

64 fasteners varieties

Hex bolt, partial threadBolts · DIN 931Hex bolt, partial thread identification drawing, not to scale

Coarse / fine thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Hex screw, full threadBolts · DIN 933Hex screw, full thread identification drawing, not to scale

Metric / imperial

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Socket head cap screwScrews · DIN 912 / ISO 4762Socket head cap screw identification drawing, not to scale

Allen drive

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Socket countersunk screwScrews · DIN 7991Socket countersunk screw identification drawing, not to scale

Flush head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Socket button-head screwScrews · Socket button-head screw identification drawing, not to scale

Low-profile rounded head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Slotted wood screwScrews · DIN 96Slotted wood screw identification drawing, not to scale

Round head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Slotted cheese-head screwScrews · DIN 84Slotted cheese-head screw identification drawing, not to scale

Machine thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Slotted countersunk screwScrews · DIN 963Slotted countersunk screw identification drawing, not to scale

Machine thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Cross-recess pan-head screwScrews · DIN 7985Cross-recess pan-head screw identification drawing, not to scale

Phillips drive

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Cross-recess countersunk screwScrews · DIN 965Cross-recess countersunk screw identification drawing, not to scale

Machine thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Slotted pan-head screwScrews · DIN 85Slotted pan-head screw identification drawing, not to scale

Machine thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Pan-head tapping screwScrews · DIN 7971Pan-head tapping screw identification drawing, not to scale

Slotted

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Countersunk tapping screwScrews · DIN 7972 / DIN 7982Countersunk tapping screw identification drawing, not to scale

Slotted / cross recess

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Truss-head screwScrews · Truss-head screw identification drawing, not to scale

Wide head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Raised countersunk screwScrews · DIN 964Raised countersunk screw identification drawing, not to scale

Slotted

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Carriage boltBolts · DIN 603Carriage bolt identification drawing, not to scale

Square neck

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Hex nutNuts · DIN 934Hex nut identification drawing, not to scale

Metric / imperial

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Thin hex locknutNuts · DIN 439Thin hex locknut identification drawing, not to scale

Jam nut

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Nylon-insert locknutNuts · DIN 982Nylon-insert locknut identification drawing, not to scale

Tall type

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Square nutNuts · DIN 557Square nut identification drawing, not to scale

Square body

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Flange nutNuts · DIN 6923Flange nut identification drawing, not to scale

Plain / serrated face

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Domed cap nutNuts · DIN 1587Domed cap nut identification drawing, not to scale

Closed end

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Wing nutNuts · DIN 315Wing nut identification drawing, not to scale

Hand tightening

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Square weld nutNuts · DIN 928Square weld nut identification drawing, not to scale

Weld projections

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Socket set screwScrews · DIN 913 / DIN 914 / DIN 915 / DIN 916Socket set screw identification drawing, not to scale

Flat / cone / dog / cup point

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Plain washerWashers · DIN 125Plain washer identification drawing, not to scale

Round

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Split spring washerWashers · DIN 127Split spring washer identification drawing, not to scale

Split ring

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

External retaining ringRetainers · DIN 471External retaining ring identification drawing, not to scale

Shaft circlip

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

E-type retaining washerRetainers · DIN 6799E-type retaining washer identification drawing, not to scale

Shaft groove

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Structural bolt assemblyStructural · ASTM F3125Structural bolt assembly identification drawing, not to scale

Bolt / nut / washer assembly

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Petrochemical stud boltStuds · ASTM A193 / ASTM A320Petrochemical stud bolt identification drawing, not to scale

Two heavy hex nuts

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Heavy hex nutNuts · ASTM A194Heavy hex nut identification drawing, not to scale

Grade-specific heat treatment

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Threaded rodStuds · Threaded rod identification drawing, not to scale

Continuous thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Double-end studStuds · Double-end stud identification drawing, not to scale

Unthreaded centre

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

U-boltAnchors & bent bolts · U-bolt identification drawing, not to scale

Pipe clamp / square bend

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

J foundation boltAnchors & bent bolts · ASTM F1554J foundation bolt identification drawing, not to scale

Bent anchor

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

L foundation boltAnchors & bent bolts · ASTM F1554L foundation bolt identification drawing, not to scale

Bent anchor

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Eye boltLifting · Eye bolt identification drawing, not to scale

Fixed / swivel designs

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Eye nutLifting · Eye nut identification drawing, not to scale

Rated lifting component

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Wedge anchorAnchors & bent bolts · Wedge anchor identification drawing, not to scale

Expansion anchor

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Coupling nutNuts · Coupling nut identification drawing, not to scale

Long hex body

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

All-metal locknutNuts · All-metal locknut identification drawing, not to scale

Prevailing torque

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Star washerWashers · Star washer identification drawing, not to scale

Internal / external teeth

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Square plate washerWashers · Square plate washer identification drawing, not to scale

Plate washer

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Direct-tension indicator washerWashers · Direct-tension indicator washer identification drawing, not to scale

Compressible protrusions

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Self-drilling screwScrews · Self-drilling screw identification drawing, not to scale

Hex / pan / countersunk head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Security screwScrews · Security screw identification drawing, not to scale

Pin-in-drive / special drive

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Hammer-drive screwScrews · Hammer-drive screw identification drawing, not to scale

Drive-in thread

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Hanger boltStuds · Hanger bolt identification drawing, not to scale

Wood / machine thread ends

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

T-boltBolts · T-bolt identification drawing, not to scale

T-slot / custom head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Cage nutNuts · Cage nut identification drawing, not to scale

Sheet-metal cage

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Shear nutNuts · Shear nut identification drawing, not to scale

Breakaway installation head

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Projection weld studStuds · Projection weld stud identification drawing, not to scale

Welded attachment

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Solid rivetRivets & inserts · Solid rivet identification drawing, not to scale

Solid shank

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Thread insertRivets & inserts · Thread insert identification drawing, not to scale

For plastics / metal, model-specific

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Self-clinching fastenerRivets & inserts · Self-clinching fastener identification drawing, not to scale

Nut / stud / spacer

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Compression limiterRivets & inserts · Compression limiter identification drawing, not to scale

Through-hole bush

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Captive-washer screwScrews · Captive-washer screw identification drawing, not to scale

Preassembled washer

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Thread-forming screwScrews · Thread-forming screw identification drawing, not to scale

Forming profile

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Spring channel nutNuts · Spring channel nut identification drawing, not to scale

Channel support fixing

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Tie rodStuds · Tie rod identification drawing, not to scale

Tie-rod assembly

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Engine connecting-rod boltSpecial fasteners · Engine connecting-rod bolt identification drawing, not to scale

Engine-specific part number

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Wind-turbine fastenerSpecial fasteners · Wind-turbine fastener identification drawing, not to scale

Project-specific assembly

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Automotive special fastenerSpecial fasteners · Automotive special fastener identification drawing, not to scale

Drawing-controlled part

Choose diameter, pitch, length, strength/material grade, coating and mating parts separately. A variety entry does not establish stock or interchangeability.

Identification sketch only. Use the exact manufacturer drawing for tolerances and manufacture.

Manufacturer-specific dimensions and PDF charts

Each table retains its own model, material, limit definitions and source page. Blank or unlisted sizes are not estimates.

Unbrako alloy-steel metric socket cap · 18 sizes/classes

Download complete branded PDF

Manufacturer engineering-guide snapshot, printed page 38. All 18 sizes retained, including non-stock and non-preferred labels. This is not a universal ISO 4762 tolerance table.

Manufacturer grade: alloy steel ASTM A574M / class 12.9. Published hardness 38–43 HRC; yield stress 1170 MPa through M16, 1125 MPa above M16; source thread class 5g 6g.

The published torque example applies to plain-finish Unbrako screws and an approximately 800 MPa thread-stress calculation under the stated VDI 2230 basis. It is not an installation torque for stainless, coated or arbitrary assemblies. Use the approved joint procedure.

Do not merge the A head maximum here with Fastenal’s ISO 4762 A4-80 product limits: that sheet permits plain or knurled heads and gives different head and engagement limits. Material/model/limit definitions remain separate.

Original manufacturer source · page 38

Unbrako alloy-steel metric socket cap
Size / classPitch (mm)A head diameter, max (mm)D body diameter, max (mm)H head height, max (mm)J socket key, nominal (mm)
M1.60.3531.61.61.5
M20.43.8221.5
M2.50.454.52.52.52
M30.55.5332.5
M40.77443
M50.88.5554
M6110665
M81.2513886
M101.51610108
M121.7518121210
(M14) · non-stock in source221141412
M16224161614
M202.530202017
M24336242419
M30 · non-stock in source3.545303022
M36 · non-stock in source454363627
M42 · non-stock in source4.563424232
M48 · non-stock in source572484836
Unbrako alloy-steel metric socket cap
Size / classG remaining head web, min (mm)T socket engagement, min (mm)UTS minimum (MPa)Tensile load minimum (kN)Tensile load minimum (lbf)
M1.60.540.813001.65370
M20.68113002.69605
M2.50.851.2513004.41990
M31.021.513006.541470
M41.522130011.42560
M51.92.5130018.54160
M62.283130026.15870
M83.24130047.610700
M1045130075.417000
M124.86130011024700
(M14) · non-stock in source5.67130015033700
M166.48130020445900
M20810125030668800
M249.612125044199100
M30 · non-stock in source12151250701158000
M36 · non-stock in source14.41812501020229000
M42 · non-stock in source16.82112501400315000
M48 · non-stock in source19.22412501840413000
Unbrako alloy-steel metric socket cap
Size / classSingle shear load minimum (kN)Single shear load minimum (lbf)Published plain-finish torque example (N·m)Published plain-finish torque example (lbf·in)
M1.61.57352.50.292.6
M22.455500.65.3
M2.53.838601.2111
M35.512402.119
M49.822054.641
M515.334459.585
M622.05496016140
M839.2880039350
M10611375077680
M1288198501351200
(M14) · non-stock in source120270002151900
M16157352503302900
M20235.5530006505750
M243397650011009700
M30 · non-stock in source530119000225019900
M36 · non-stock in source756171500385034100
M42 · non-stock in source1040233500627055580
M48 · non-stock in source1355305000856075800
Published length tolerances, mm
Length (mm)M1.6–M10M12–M20over M20
≤16± 0.3± 0.3Not listed
>16–50± 0.4± 0.4± 0.7
>50–120± 0.7± 1± 1.5
>120–200± 1± 1.5± 2
>200± 2± 2.5± 3
Fastenal ISO 4762 A4-80 · Rev 03 / 2023 · 17 sizes/classes

Download complete branded PDF

Product-sheet limits, revision 03 dated 1 March 2023. A4-80 per ISO 3506-1; thread tolerance 6g; plain or knurled heads permitted. All 17 published rows retained.

This is a distinct product specification from the Unbrako alloy-steel chart. Different head and engagement limits are preserved, not averaged. No M48 or other absent sizes are extrapolated.

Original manufacturer source · page 1

Fastenal ISO 4762 A4-80 · Rev 03 / 2023
Size / classds body diameter, max (mm)ds body diameter, min (mm)dk head diameter, max (mm)dk head diameter, min (mm)k head height, max (mm)
M1.61.61.463.142.861.6
M221.863.983.622
M2.52.52.364.684.322.5
M332.865.685.323
M443.827.226.784
M554.828.728.285
M665.8210.229.786
M887.7813.2712.738
M10109.7816.2715.7310
M121211.7318.2717.7312
M141413.7321.3320.6714
M161615.7324.3323.6716
M202019.6730.3329.6720
M242423.6736.3935.6124
M303029.6745.3944.6130
M363635.6154.4653.5436
M424241.6163.4662.5442
Fastenal ISO 4762 A4-80 · Rev 03 / 2023
Size / classk head height, min (mm)s socket opening, max (mm)s socket opening, min (mm)t key engagement, min (mm)
M1.61.461.581.520.7
M21.861.581.521
M2.52.362.082.021.1
M32.862.582.521.3
M43.823.083.022
M54.824.0954.022.5
M65.75.145.023
M87.646.146.024
M109.648.1758.0255
M1211.5710.17510.0256
M1413.5712.21212.0327
M1615.5714.21214.0328
M2019.4817.2317.0510
M2423.4819.27519.06512
M3029.4822.27522.06515.5
M3635.3827.27527.06519
M4241.3832.3332.0824

Material and grade designations

A material alloy, bolt grade, nut grade and mechanical property class describe different requirements. These references supplement the 318-grade finder; they are not automatic equivalents.

Bolt property class 4.6Metric mechanical class

Mechanical class is separate from alloy composition and dimensional standard; specify the relevant ISO 898-1 / IS 1367 edition.

Bolt property class 8.8Metric mechanical class

Mechanical class is separate from alloy composition and dimensional standard; specify the relevant ISO 898-1 / IS 1367 edition.

Bolt property class 10.9Metric mechanical class

Mechanical class is separate from alloy composition and dimensional standard; specify the relevant ISO 898-1 / IS 1367 edition.

ISO 898-1 class 12.9Metric mechanical class

Full-size geometry, product standard, diameter and test conditions apply. Not a stainless steel grade.

A2-50Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

A2-70Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

A2-80Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

A4-50Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

A4-70Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

A4-80Stainless fastener designation

ISO 3506 combines a steel-group designation and a property class. It does not establish exact AISI alloy equivalence for every product.

BUMAX 88Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX 109Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX SDX 109Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX DX 129Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX DX 149Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX NITRO 109Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX SAProprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX HEProprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

BUMAX ULTRA 159Proprietary fastener grade

Use the manufacturer material sheet and product dimensions; do not interpret the trade name as a universal ISO class.

ASTM A193 B5Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B6Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B7Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B7MBolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8 Class 1Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8 Class 2Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8M Class 1Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8M Class 2Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8CBolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8SBolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B8TBolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A193 B16Bolting

Specify full grade, class, diameter and heat treatment; properties can vary with diameter. Raw alloy names are not fastener certification.

ASTM A320 L7Low-temperature bolting

Order the applicable class and impact-test requirements, not just an alloy name.

ASTM A320 L7MLow-temperature bolting

Order the applicable class and impact-test requirements, not just an alloy name.

ASTM A320 L43Low-temperature bolting

Order the applicable class and impact-test requirements, not just an alloy name.

ASTM A320 B8Low-temperature bolting

Order the applicable class and impact-test requirements, not just an alloy name.

ASTM A320 B8MLow-temperature bolting

Order the applicable class and impact-test requirements, not just an alloy name.

ASTM A194 Grade 2HFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A194 Grade 2HMFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A194 Grade 8Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A194 Grade 8MFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A307 Grade AFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A307 Grade BFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A354 Grade BCFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM A354 Grade BDFastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM F1554 Grade 36Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM F1554 Grade 55Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM F1554 Grade 105Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM F3125 Grade A325Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

ASTM F3125 Grade A490Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

SAE J429 Grade 2Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

SAE J429 Grade 5Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

SAE J429 Grade 8Fastener specification

Grade labels are specific to this standard. They are not interchangeable with ISO property classes.

Stainless 304Alloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 304LAlloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 316Alloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 316LAlloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 410Alloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 430Alloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

Stainless 310Alloy designation

Alloy designation only; specify the fastener product standard, mechanical condition and certification separately.

309Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

317LSpecial fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

321Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

330Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

347Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

501Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Alloy 20Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Alloy 400Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Duplex 2205Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Hastelloy C-276Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Nitronic 60Special fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Silicon bronzeSpecial fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

BrassSpecial fastener material

Manufacturer catalogue material lead, not an automatic equivalent or a universal availability claim.

Duplex 2507Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Inconel 600Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Inconel 625Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Inconel 718Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Inconel 925Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Monel K-500Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

Nitronic 50Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

17-4 PHSpecial fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

A286Special fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

TitaniumSpecial fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

AluminiumSpecial fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

AL6XNSpecial fastener material

Confirm the exact UNS/product specification, condition and order certificate. No generic strength is assigned.

8740ARP engine-fastener material

Manufacturer-specific application and tightening instructions apply. Not a substitute for structural or pressure-service bolting.

ARP2000ARP engine-fastener material

Manufacturer-specific application and tightening instructions apply. Not a substitute for structural or pressure-service bolting.

L19ARP engine-fastener material

Manufacturer-specific application and tightening instructions apply. Not a substitute for structural or pressure-service bolting.

Indian and international catalogue sources

Source references do not imply that Steel Impex India stocks, represents or is endorsed by these brands. Delhi NCR and Punjab locations identify the cited source; they are not branch-office claims.

APL / Agarwal Fasteners

India · Maharashtra · Manufacturer

Stainless fastener product index; individual order drawings govern dimensions.

Visit source catalogue

Source checked 2026-11-11

Unbrako engineering guide

India / international · Manufacturer

ISO 898-1 class 12.9 socket products; confirm current drawing and product edition.

Visit source catalogue

Source checked 2026-11-11

Fastenal

USA / international · Manufacturer / distributor

ISO 4762 A4-80 socket cap product sheet, revision 03 dated 1 March 2023. Limits remain separate from Unbrako alloy-steel data.

Visit source catalogue

Source checked 2026-11-11

Unbrako / Deepak Fasteners

India · Punjab / international · Manufacturer

Socket, hex, structural and petrochemical fasteners; published catalogue edition must be checked when ordering.

Visit source catalogue

Source checked 2026-11-11

Portland Bolt

USA · Manufacturer

ASTM fastener specification scopes; superseded A325/A490 references distinguished from F3125.

Visit source catalogue

Source checked 2026-11-11

FIT Bolts

International · Manufacturer

Petrochemical stud material and treatment descriptions.

Visit source catalogue

Source checked 2026-11-11

Rushabh Fastners · RF

India · Mumbai · Importer / stockist

Product variety reference. Advertised prices are excluded; material certification is order-specific.

Visit source catalogue

Source checked 2026-11-11

Kanda Brothers

India · Punjab / Ludhiana · Manufacturer

Rods, nuts, bolts and washers; catalogue is a variety guide, not a complete tolerance table.

Visit source catalogue

Source checked 2026-11-11

Kundan Industries

India · Manufacturer

Bolts, nuts, screws, studs, washers, special thread forms and stainless material designations.

Visit source catalogue

Source checked 2026-11-11

Nedschroef

International · Manufacturer / sourcing network

Standard catalogue and specialist automotive fastener literature.

Visit source catalogue

Source checked 2026-11-11

Bulten product range

International · Manufacturer / sourcing network

Standard and special fasteners, inserts and clinch products. Catalogue identity is not an ownership ranking.

Visit source catalogue

Source checked 2026-11-11

ARP

USA · Manufacturer

Engine fastener proprietary alloys; do not substitute these for general industrial strength classes.

Visit source catalogue

Source checked 2026-11-11

Sundram Fasteners

India · Tamil Nadu · Manufacturer

Automotive, wind energy and aerospace fastener families.

Visit source catalogue

Source checked 2026-11-11

Sterling Tools

India · Delhi NCR / Faridabad · Manufacturer

Automotive fasteners. Faridabad is in Haryana, not Delhi city.

Visit source catalogue

Source checked 2026-11-11

Coverage and unresolved source issues

Original drawings are identification schematics, not fabrication drawings or standard P&ID symbols.

DIN references are catalogue designations, not claims of current validity or exact ISO equivalence. Order the required edition.

APL lists DIN 7981 as a low-head Allen screw, which conflicts with the pan-head tapping-screw designation. It is held for clarification, not silently imported.

Manufacturer ranking and supply affiliation are not claimed.

Model-specific valve tables and complete fastener tolerance tables are still under review. Use linked manufacturer drawings; missing dimensions are never filled by voting or extrapolation.

Published differences between standards, editions or models remain separate even if multiple websites repeat one value.

Prepare a bulk enquiry for delivery within India

Include the material grade, standard and edition, complete size, quantity, finish, certificates, required date and delivery PIN code. For valves include body/trim, seats, service fluid, temperature, end connection and actuator. For fasteners include thread, pitch, length, property class and coating.

For a village, small town or large city, give the district, nearest transport depot and unloading arrangements. Stock, suitability, freight and delivery are confirmed for each order.

Prepare your material enquiry Delivery checklist

Common questions

Are SS 304 and A2-70 the same specification?

SS 304 names an alloy grade; A2-70 is a stainless fastener designation combining a steel group with a mechanical property class. Specify the fastener standard and full designation, and confirm the material certificate. A raw-material name alone does not define a finished bolt.

Why are the Unbrako and Fastenal socket-cap dimensions separate?

They describe different material and product scopes. Fastenal’s A4-80 ISO 4762 sheet allows plain or knurled heads and gives limit dimensions that can differ from Unbrako’s alloy-steel engineering guide. The original definitions and limits remain separate.

What should a bulk buyer send for a quotation?

Send the exact standard and edition, grade or class, complete dimensions, quantity, finish, certification and delivery town, district and PIN code. Include the nearest transport depot for village or small-town delivery. Availability, price, freight and delivery are confirmed against your enquiry.

Reference sources and corrections · Toolkit terms. Source scope, units and missing values remain part of every reference. A catalogue listing is not a stock guarantee, approval for substitution or brand affiliation.