# Butt-weld short-radius 90° elbows (ASME B16.9 / B16.28), NPS 1 to 12: centre-to-end = 1 × NPS

> What is the centre-to-end of a short-radius (SR) 90° butt-weld elbow, and how does it differ from long radius?

- Category: Tri-clamp & pipe › Pipe, tube & threads
- Kind: Standard part
- Basis: Centre-to-end A (mm) from Wermac's ASME B16.9 short-radius table, cross-checked with Texas Flange's inch table; OD and Schedule 40 wall per ASME B36.10 (Texas Flange)
- Page: https://xemstudio.com/objects/butt-weld-elbows-short-radius/ · JSON: https://xemstudio.com/api/geometry?object=butt-weld-elbows-short-radius · Plain text: https://xemstudio.com/objects/butt-weld-elbows-short-radius/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part.

## Notes

- A short-radius (SR) elbow turns on a bend radius of 1 × NPS, so centre-to-end A equals the nominal size in inches (NPS 2 = 2.00 in = 51 mm). A long-radius (LR) elbow turns on 1.5 × NPS (see butt-weld-elbows-long-radius) and a 3D elbow on 3 × NPS (butt-weld-elbows-3d). Short radius starts at NPS 1 in the tables read; there is no NPS 1/2 or 3/4 short-radius row.
- Both sources agree: the inch value (Texas Flange) times 25.4 matches Wermac's mm value within rounding for every size (for example NPS 4: 4.00 in = 101.6 mm, printed 102 mm). The mm column is the standard's rounded metric figure; the inch column is the exact bend radius. Texas Flange notes that OD and A are the same for every schedule: only the wall changes.
- Wermac prints the manufacturing tolerance on A as ±2 mm for NPS 1/2 to 24 and on OD at the bevel as +1.6 / −0.8 mm for NPS 1/2 to 2-1/2, ±1.6 mm for NPS 3 to 4, +2.4 / −1.6 mm for NPS 5 to 8 and +4 / −3.2 mm for NPS 10 to 18. Wall: not less than 87.5% of the nominal wall.
- Files at NPS 1, 2 and 4, Schedule 40, hollow: a torus section of the pipe's OD and wall, bend radius equal to the published centre-to-end (inch value × 25.4), so the end faces sit exactly A from the intersection of the two pipe axes. This is the full shape: a circular bend is defined by A, OD and wall.
- OD and Schedule 40 wall: the tables print OD rounded (1.32, 2.38, 4.50 in); the files use the exact ASME B36.10 OD (1.315, 2.375, 4.500 in) with the Sch 40 wall (.133, .154, .237 in) that Texas Flange prints for each size. Fittings are made to match the pipe's OD and wall.
- Ends are drawn square. Real fittings are bevelled for welding to ASME B16.25; no public, citable statement of the bevel was found, so it is not drawn.
- Heavier schedules change only the wall: use the OD from the table and a wall from the pipe schedule (Sch 80 NPS 2 is 0.218 in, Sch 80 NPS 4 0.337 in).

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| weld ends | OD = pipe OD (Ø33.40 / Ø60.33 / Ø114.30 at NPS 1 / 2 / 4), wall = Sch 40 (3.38 / 3.91 / 6.02) | Schedule 40 pipe of the same NPS, butt-welded (schedule-40-pipe) | designed | bw-elbow-90-sr* |
| centre-to-end A | 25.4 / 50.8 / 101.6 (= 1 × NPS in) | pipe run set-back: face-to-axis distance of the next fitting or flange | designed | bw-elbow-90-sr* |

## Sizes

| NPS | OD, mm | centre-to-end A, mm (Wermac) | centre-to-end A, in (Texas Flange) | Sch 40 wall |
|---|---|---|---|---|
| 1 | 33.4 (1.32 in) | 25 | 1.00 | 0.133 in (3.38 mm) |
| 1-1/4 | 42.2 (1.66 in) | 32 | 1.25 | 0.140 in (3.56 mm) |
| 1-1/2 | 48.3 (1.90 in) | 38 | 1.50 | 0.145 in (3.68 mm) |
| 2 | 60.3 (2.38 in) | 51 | 2.00 | 0.154 in (3.91 mm) |
| 2-1/2 | 73.0 (2.88 in) | 64 | 2.50 | 0.203 in (5.16 mm) |
| 3 | 88.9 (3.50 in) | 76 | 3.00 | 0.216 in (5.49 mm) |
| 3-1/2 | 101.6 (4.00 in) | 89 | 3.50 | 0.226 in (5.74 mm) |
| 4 | 114.3 (4.50 in) | 102 | 4.00 | 0.237 in (6.02 mm) |
| 5 | 141.3 (5.56 in) | 127 | 5.00 | 0.258 in (6.55 mm) |
| 6 | 168.3 (6.62 in) | 152 | 6.00 | 0.280 in (7.11 mm) |
| 8 | 219.1 (8.62 in) | 203 | 8.00 | 0.322 in (8.18 mm) |
| 10 | 273.0 (10.75 in) | 254 | 10.00 | 0.365 in (9.27 mm) |
| 12 | 323.8 (12.75 in) | 305 | 12.00 | 0.406 in (10.31 mm) |

## Where the files are

- Wermac: [ASME B16.9 90 deg short-radius elbow dimensions and tolerances (mm)](https://www.wermac.org/fittings/dim_elbows_b.html) — web — Publisher's page; dimensions are facts
- Texas Flange (manufacturer / distributor): [Butt-weld 90 deg short-radius elbows (ASME B16.28): OD and centre-to-end by NPS, all schedules](https://texasflange.com/butt-weld-fittings/elbow-short-radius/) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [Metal pipe fittings (butt-weld elbows, tees, reducers, caps) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/metal-pipe-fittings/) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Free STEP/STL (3 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/index.json

- bw-elbow-90-sr-nps1-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps1-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps1-sch40.stl) — NPS 1 Sch 40 short-radius 90° elbow: OD 33.40 × 3.38 wall, bend radius = centre-to-end 25.4 mm; ends square
- bw-elbow-90-sr-nps2-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps2-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps2-sch40.stl) — NPS 2 Sch 40 short-radius 90° elbow: OD 60.32 × 3.91 wall, bend radius = centre-to-end 50.8 mm; ends square
- bw-elbow-90-sr-nps4-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps4-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-short-radius/bw-elbow-90-sr-nps4-sch40.stl) — NPS 4 Sch 40 short-radius 90° elbow: OD 114.30 × 6.02 wall, bend radius = centre-to-end 101.6 mm; ends square

## Questions

**What is the centre-to-end of a 2 inch short-radius elbow?**

51 mm (2.00 in): short-radius centre-to-end equals the nominal pipe size in inches.

**What is the difference between a short-radius and a long-radius elbow?**

Bend radius: 1 × NPS for short radius (A = 2.00 in at NPS 2), 1.5 × NPS for long radius (A = 3.00 in at NPS 2).

**Is the short-radius elbow the same for Schedule 40 and 80?**

Yes: OD and centre-to-end are the same, only the wall thickness differs (Texas Flange prints one table for all schedules).

## Fits with

- [Butt-weld elbows, 90° and 45° long radius (ASME B16.9), NPS ½ to 12](https://xemstudio.com/objects/butt-weld-elbows-long-radius/)
- [Butt-weld 3D (3R) elbows, 90° and 45° (ASME B16.9), NPS 3/4 to 12: centre-to-end 3 × NPS](https://xemstudio.com/objects/butt-weld-elbows-3d/)
- [Butt-weld 180° return bends, long and short radius (ASME B16.9), NPS 1/2 to 12: centre-to-centre O and back-to-face K](https://xemstudio.com/objects/butt-weld-return-bends-180/)
- [Butt-weld equal tees (ASME B16.9), NPS ½ to 12](https://xemstudio.com/objects/butt-weld-equal-tees/)
- [Butt-weld reducers, concentric and eccentric (ASME B16.9), NPS ¾ to 12](https://xemstudio.com/objects/butt-weld-reducers/)
- [Schedule 40 pipe and PVC fittings, 1/2 to 2 inch](https://xemstudio.com/objects/schedule-40-pipe/)
- [ASME B16.5 Class 150 pipe flanges, NPS ½ to 24: dimensions, bolt circle, slip-on and blind](https://xemstudio.com/objects/asme-b16-5-class-150-flanges/)