ASME B16.5 — Stud bolts RF / RTJ — Class 150
ASME B16.5 Stud bolts RF / RTJ — Class 150 — 20 sizes.
| NPS | No. of studs | Stud dia. (in) | Stud length RF (mm) | Stud length RTJ (mm) |
|---|---|---|---|---|
| 1/2 | 4 | 1/2 | 55 | — |
| 3/4 | 4 | 1/2 | 65 | — |
| 1 | 4 | 1/2 | 65 | 75 |
| 1-1/4 | 4 | 1/2 | 70 | 85 |
| 1-1/2 | 4 | 1/2 | 70 | 85 |
| 2 | 4 | 5/8 | 85 | 95 |
| 2-1/2 | 4 | 5/8 | 90 | 100 |
| 3 | 4 | 5/8 | 90 | 100 |
| 3-1/2 | 8 | 5/8 | 90 | 100 |
| 4 | 8 | 5/8 | 90 | 100 |
| 5 | 8 | 3/4 | 95 | 110 |
| 6 | 8 | 3/4 | 100 | 115 |
| 8 | 8 | 3/4 | 110 | 120 |
| 10 | 12 | 7/8 | 115 | 125 |
| 12 | 12 | 7/8 | 120 | 135 |
| 14 | 12 | 1 | 135 | 145 |
| 16 | 16 | 1 | 135 | 145 |
| 18 | 16 | 1-1/8 | 145 | 160 |
| 20 | 20 | 1-1/8 | 160 | 170 |
| 24 | 20 | 1-1/4 | 170 | 185 |
- Wermac convention: length excludes points (chamfers); RF lengths allow for one spiral wound gasket (4.5 mm sealing element compressed to ~3 mm). Other publishers use different allowances and round differently — lengths are not interchangeable between tables.
- Wermac table; ThePipingMart and Globe United reproduce identical values (likely mirrors, not fully independent). Texas Flange NPS 4 (8 x 5/8 in, 3-1/2 in RF / 4 in RTJ) and an inch chart (NPS 24 6-3/4 / 7-1/4 in) are consistent.
- No RTJ flange for NPS 1/2, 3/4 in Class 150.
- Project Materials and Piping-World give different mm lengths (e.g. NPS 24 RF 180 mm) — not used.
Sources: wermac.org/bolts/dimensions_stud-bolts_class-150_rf-rtj-flan · blog.thepipingmart.com/dimensions/pipe-fittings/dimensions-s · globeunitedae.com/stud-bolts-dimensions-for-rf-rtj-flanges-a · texasflange.com/products/flange-dims-weights/bolt-and-stud-d · concretecalculate.com/flange-bolt-size-chart/