Class 30051.1 bar @ 38 °C · Group 1.1
ASME B16.5 Class 300 stud bolt chart
Twice the pressure of Class 150 and noticeably more bolts. Note that NPS 2 jumps from four studs to eight — a detail that catches people re-bolting from a Class 150 drawing.
No matching rows.
| NPS | Qty | Stud size | ≈ metric | Bolt circle | Stud length (in) | Stud length (mm) |
|---|---|---|---|---|---|---|
| ½" | 4 | ½" | M12 | 2.62" · 65 mm | 2.5" | 65 |
| ¾" | 4 | ⅝" | M16 | 3.25" · 85 mm | 3" | 75 |
| 1" | 4 | ⅝" | M16 | 3.5" · 90 mm | 3" | 75 |
| 1¼" | 4 | ⅝" | M16 | 3.88" · 100 mm | 3.25" | 85 |
| 1½" | 4 | ¾" | M20 | 4.5" · 115 mm | 3.5" | 90 |
| 2" | 8 | ⅝" | M16 | 5" · 125 mm | 3.5" | 90 |
| 2½" | 8 | ¾" | M20 | 5.88" · 150 mm | 4" | 100 |
| 3" | 8 | ¾" | M20 | 6.62" · 170 mm | 4.25" | 110 |
| 3½" | 8 | ¾" | M20 | 7.25" · 185 mm | 4.25" | 110 |
| 4" | 8 | ¾" | M20 | 7.88" · 200 mm | 4.5" | 115 |
| 5" | 8 | ¾" | M20 | 9.25" · 235 mm | 4.75" | 120 |
| 6" | 12 | ¾" | M20 | 10.62" · 270 mm | 4.75" | 120 |
| 8" | 12 | ⅞" | M22 | 13" · 330 mm | 5.5" | 140 |
| 10" | 16 | 1" | M24 | 15.25" · 385 mm | 6.25" | 160 |
| 12" | 16 | 1⅛" | M27 | 17.75" · 450 mm | 6.75" | 170 |
| 14" | 20 | 1⅛" | M27 | 20.25" · 515 mm | 7" | 180 |
| 16" | 20 | 1¼" | M30 | 22.5" · 570 mm | 7.5" | 190 |
| 18" | 24 | 1¼" | M30 | 24.75" · 630 mm | 7.75" | 195 |
| 20" | 24 | 1¼" | M30 | 27" · 685 mm | 8.25" | 210 |
| 24" | 24 | 1½" | M36 | 32" · 815 mm | 9.25" | 235 |
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