STEEL IMPEX INDIA
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GSTIN 27ADJPJ5621J1ZF · Reference copy · 11 November 2026

STEEL IMPEX INDIA · ENGINEERING REFERENCE

Spectacle Blind & Spacer Dimensions | Line Blanks

Check spectacle blind and spacer dimensions by NPS, class and facing. ASME B16.48 reference notes and unresolved source conflicts remain visible. Select the exact size/class and facing used by the order; keep the stated source units and revision with the values.

Compiled by Steel Impex India · Source review 11 November 2026 · Values match app v1.5.11

Open reference Common questions

ASME B16.48-2020 · Class 150 · Raised Face · mm · All listed sizes

Published dimensional reference snapshot, retrieved 2026-11-11. Confirm the specified standard edition, tolerances and manufacturer drawing before manufacture or purchase. A missing value remains Not listed.

Metric and inch dimensions preserve their separately published values where available; minor rounding differences are expected.

RF, female RTJ and male RTJ blanks are different designs. Male RTJ outside diameter is not tabulated here; use the ring geometry drawing. Published thickness excludes optional raised faces. The ring profile, groove and web thickness require their specified drawings.

Metric and inch columns are separately published standard values, not exact conversions. For NPS 1 Class 1500 RF web width W, the standard prints 64 mm and 2.20 in, which disagree. SFF publishes 64 mm and Aitken publishes 2.20 in; both source values are retained and flagged for drawing confirmation. No inferred replacement is applied.

Line blanks / spectacle blinds · dimensions 1–4
NPS (in)	Inside diameter B	Outside diameter O	Centre distance A	Thickness T
0.5	16 mm	45 mm	60 mm	3 mm
0.75	21 mm	54 mm	70 mm	3 mm
1	27 mm	64 mm	80 mm	3 mm
1.25	42 mm	73 mm	90 mm	6.4 mm
1.5	48 mm	83 mm	100 mm	6.4 mm
2	61 mm	102 mm	120 mm	6.4 mm
2.5	73 mm	121 mm	140 mm	6.4 mm
3	89 mm	133 mm	150 mm	6.4 mm
3.5	102 mm	159 mm	175 mm	9.7 mm
4	114 mm	171 mm	190 mm	9.7 mm
5	141 mm	194 mm	215 mm	9.7 mm
6	168 mm	219 mm	240 mm	12.7 mm
8	219 mm	276 mm	300 mm	12.7 mm
10	273 mm	337 mm	360 mm	15.7 mm
12	324 mm	406 mm	430 mm	19.1 mm
14	356 mm	448 mm	475 mm	19.1 mm
16	406 mm	511 mm	540 mm	22.4 mm
18	457 mm	546 mm	580 mm	25.4 mm
20	508 mm	603 mm	635 mm	28.4 mm
24	610 mm	714 mm	750 mm	31.8 mm

Line blanks / spectacle blinds · dimensions 5–5
NPS (in)	Web width W
0.5	38 mm
0.75	38 mm
1	38 mm
1.25	38 mm
1.5	38 mm
2	51 mm
2.5	51 mm
3	64 mm
3.5	64 mm
4	64 mm
5	76 mm
6	76 mm
8	76 mm
10	102 mm
12	102 mm
14	108 mm
16	108 mm
18	114 mm
20	121 mm
24	140 mm

Reference sources

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 every size and class combination available?

No. The charts preserve the published combinations and label manufacturer specials or conflicts. “Not listed” is not a zero dimension and is not permission to interpolate a missing size.

Are inch fasteners interchangeable with converted metric sizes?

No. Converting an inch diameter for display does not change its thread series or fit. Order the specified thread, pitch or TPI, tolerance class, length convention and material.

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.