# Butt-weld 3D (3R) elbows, 90° and 45° (ASME B16.9), NPS 3/4 to 12: centre-to-end 3 × NPS

> What is the centre-to-end of a 3D (3R) butt-weld elbow, 90° and 45°?

- Category: Tri-clamp & pipe › Pipe, tube & threads
- Kind: Standard part
- Basis: Centre-to-end A (90°) and B (45°) in mm from Wermac's ASME B16.9 3D table; the 90° value cross-checked against Texas Flange's 3R inch table; OD and Sch 40 wall per ASME B36.10
- Page: https://xemstudio.com/objects/butt-weld-elbows-3d/ · JSON: https://xemstudio.com/api/geometry?object=butt-weld-elbows-3d · Plain text: https://xemstudio.com/objects/butt-weld-elbows-3d/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 3D elbow (also called 3R) turns on a centreline radius of 3 × the nominal pipe size: for a 90° elbow centre-to-end A equals the bend radius, 3.00 in at NPS 1 (76 mm) and 6.00 in at NPS 2 (152 mm). Texas Flange: 'A 3R elbow turns on a centreline radius of three times the nominal pipe diameter'. Wermac's mm column and Texas Flange's inch column agree for every size from NPS 3/4 to 12.
- The 45° centre-to-end B is Wermac's mm table only; no second source for the 45° 3D value was read. Wermac prints no NPS 1/2 row for 3D. B is close to, but not exactly, R × tan 22.5° (NPS 1: 31 printed vs 31.6 from the radius), so no 45° file is drawn: the table value and a pure circular arc would disagree.
- Files: the 90° 3D elbow at NPS 1, 2 and 4, Schedule 40, hollow: a torus section with bend radius equal to the published centre-to-end (3 × NPS), so the faces sit exactly A from the intersection of the pipe axes.
- Long radius (1.5 × NPS) is butt-weld-elbows-long-radius, short radius (1 × NPS) is butt-weld-elbows-short-radius.
- 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.

## 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-90-3d* |
| centre-to-end A | 76.2 / 152.4 / 304.8 (= 3 × NPS in) | pipe run set-back to the next fitting or flange face | designed | bw-elbow-90-3d* |

## Sizes

| NPS | OD, mm | 90° 3D centre-to-end A, mm (Wermac) | 90° 3D centre-to-end, in (Texas Flange) | 45° 3D centre-to-end B, mm (Wermac) | Sch 40 wall |
|---|---|---|---|---|---|
| 3/4 | 26.7 (1.05 in) | 57 | 2.25 | 24 | 0.113 in (2.87 mm) |
| 1 | 33.4 (1.32 in) | 76 | 3.00 | 31 | 0.133 in (3.38 mm) |
| 1-1/4 | 42.2 (1.66 in) | 95 | 3.75 | 39 | 0.140 in (3.56 mm) |
| 1-1/2 | 48.3 (1.90 in) | 114 | 4.50 | 47 | 0.145 in (3.68 mm) |
| 2 | 60.3 (2.38 in) | 152 | 6.00 | 63 | 0.154 in (3.91 mm) |
| 2-1/2 | 73.0 (2.88 in) | 190 | 7.50 | 79 | 0.203 in (5.16 mm) |
| 3 | 88.9 (3.50 in) | 229 | 9.00 | 95 | 0.216 in (5.49 mm) |
| 3-1/2 | 101.6 (4.00 in) | 267 | 10.50 | 111 | 0.226 in (5.74 mm) |
| 4 | 114.3 (4.50 in) | 305 | 12.00 | 127 | 0.237 in (6.02 mm) |
| 5 | 141.3 (5.56 in) | 381 | 15.00 | 157 | 0.258 in (6.55 mm) |
| 6 | 168.3 (6.62 in) | 457 | 18.00 | 189 | 0.280 in (7.11 mm) |
| 8 | 219.1 (8.62 in) | 610 | 24.00 | 252 | 0.322 in (8.18 mm) |
| 10 | 273.0 (10.75 in) | 762 | 30.00 | 316 | 0.365 in (9.27 mm) |
| 12 | 323.8 (12.75 in) | 914 | 36.00 | 378 | 0.406 in (10.31 mm) |

## Where the files are

- Wermac: [ASME B16.9 long radius, 3D and 45 deg elbow dimensions (mm)](https://wermac.org/fittings/dim_elbows_a.html) — web — Publisher's page; dimensions are facts
- Texas Flange (manufacturer / distributor): [Butt-weld 90 deg 3R elbows: OD and centre-to-end by NPS](https://texasflange.com/butt-weld-fittings/elbow-90-3r/) — 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-3d/index.json

- bw-elbow-90-3d-nps1-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps1-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps1-sch40.stl) — NPS 1 Sch 40 3D (3R) 90° elbow: OD 33.40 × 3.38 wall, bend radius = centre-to-end 76.2 mm; ends square
- bw-elbow-90-3d-nps2-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps2-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps2-sch40.stl) — NPS 2 Sch 40 3D (3R) 90° elbow: OD 60.32 × 3.91 wall, bend radius = centre-to-end 152.4 mm; ends square
- bw-elbow-90-3d-nps4-sch40: [STEP](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps4-sch40.step) · [STL](https://xemstudio.com/files/hardware/butt-weld-elbows-3d/bw-elbow-90-3d-nps4-sch40.stl) — NPS 4 Sch 40 3D (3R) 90° elbow: OD 114.30 × 6.02 wall, bend radius = centre-to-end 304.8 mm; ends square

## Questions

**What is the centre-to-end of a 2 inch 3D elbow?**

152 mm (6.00 in) for the 90°, and 63 mm for the 45° (Wermac).

**What is a 3D elbow?**

An elbow with a bend radius of 3 × the nominal pipe size (3R), gentler than a 1.5D long-radius elbow; centre-to-end of a 90° equals the bend radius.

## 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 short-radius 90° elbows (ASME B16.9 / B16.28), NPS 1 to 12: centre-to-end = 1 × NPS](https://xemstudio.com/objects/butt-weld-elbows-short-radius/)
- [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/)