Standard Thread Pitch Chart

Stel World GMBH Standard Thread Pitch Chart

Coarse Thread Series – UNC Fine Thread Series – UNF 8-Thread Series – 8UN
Nominal Size and Threads Per In. Basic Pitch Dia. Section at Minor Dia. Tensile Stress Area Nominal Size and Threads Per In. Basic Pitch Dia. Section @ Minor Dia. Tensile Stress Area Nominal Size and Threads Per In. Basic Pitch Dia. Section @ Minor Dia.
In. Sq in. Sq in. In. Sq in. Sq in. In. Sq in.
3⁄8 – 16 0.3344 0.0678 0.0775 3⁄8 – 24 0.3479 0.0809 — — — —
7⁄16 – 14 0.3911 0.0933 0.1063 7⁄16 – 20 0.405 0.109 — — — —
1⁄2 – 13 0.45 0.1257 0.1419 1⁄2 – 20 0.4675 0.1486 — — — —
9⁄16 – 12 0.5084 0.162 0.182 9⁄16 – 18 0.5264 0.189 — — — —
5⁄8 – 11 0.566 0.202 0.226 5⁄8 – 18 0.5889 0.24 — — — —
3⁄4 – 10 0.685 0.302 0.334 3⁄4 – 16 0.7094 0.351 — — — —
7⁄8 – 9 0.8028 0.419 0.462 7⁄8 – 14 0.8286 0.48 — — — —
1-8 0.9188 0.551 0.606 1-12 0.9459 0.625 1-8 0.9188 0.551
11⁄8 – 7 1.0322 0.693 0.763 11⁄8 – 12 1.0709 0.812 11⁄8 – 8 1.0438 0.728
11⁄4 – 7 1.1572 0.89 0.969 11⁄4 – 12 1.1959 1.024 11⁄4 – 8 1.1688 0.929
13⁄8 – 6 1.2667 1.054 1.155 13⁄8 – 12 1.3209 1.26 13⁄8 – 8 1.2938 1.155
11⁄2 – 6 1.3917 1.294 1.405 11⁄2 – 12 1.4459 1.521 11⁄2 – 8 1.4188 1.405
— — — — — — — — — 15⁄8 – 8 1.5438 1.68
13⁄4 – 5 1.6201 1.74 1.90 — — — — — 13⁄4 – 8 1.6688 1.98
— — — — — — — — — 17⁄8 – 8 1.7938 2.3
2 – 41⁄2 1.8557 2.3 2.50 — — — — — 2-8 1.9188 2.65
21⁄4-4-1⁄2 2.1057 3.02 3.25 — — — — — 21⁄4 – 8 2.1688 3.42
21⁄2 – 4 2.3376 3.72 4.00 — — — — — 21⁄2 – 8 2.4188 4.29
23⁄4 – 4 2.5876 4.62 4.93 — — — — — 23⁄4 – 8 2.6688 5.26
3-4 2.8376 5.62 5.97 — — — — — 3 – 8 2.9188 6.32
31⁄4 – 4 3.0876 6.72 7.10 — — — — — 31⁄4 – 8 3.1688 7.49
31⁄2 – 4 3.3376 7.92 8.33 — — — — — 31⁄2 – 8 3.4188 8.75
33⁄4 – 4 3.5876 9.21 9.66 — — — — — 33⁄4 – 8 3.6688 10.11
4-4 3.8376 10.61 11.08 — — — — — 4 – 8 3.9188 11.57

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