Threads / Size reference

1 3/16-18 UNEF

1 3/16-18 has a nominal outside diameter of 30.1625 mm and a 1.411111 mm pitch.

Nominal major diameter1.1875 in

30.1625 mm

Threads per inch18 TPI

1.411111 mm pitch

Nominal dimensions; no class allowances or acceptance limits applied. Diameter is in inches; the number after the dash is TPI.

1 3/16-18 · PITCH VIEWSCHEMATIC
PP = 1.411111 mm · 18 TPI

nearby diameter comparison

1 3/16-18 vs 1 1/8-18

There is no second pitch at this diameter in the directory. Compare the nearby 1 1/8-18 UNEF: its nominal diameter differs by 1.5875 mm. It is not a replacement.

Swipe to compare both sizes →

Nominal size comparison
Property1 3/16-18 UNEF1 1/8-18 UNEF
Nominal diameter · inDifferent1.18751.125
Nominal diameter · mmDifferent30.162528.575
Threads per inch1818
Pitch · mm1.4111111.411111
Tap-maker data needed

Tapping-hole evidence for 1 3/16-18

No reviewed chart row for 1 3/16-18 UNEF

No UNEF drill row or UNEF-specific equation scope has been reviewed. Use the exact tap maker’s data; a UNC/UNF drill at the same diameter is not a substitute.

Need acceptance limits?

The complete class and applicable drawing requirements are needed. These nominal values are not maximum/minimum inspection limits.

Part has no marking?

Measure the correct diameter and pitch, then compare candidates across metric and inch systems.

Basis for this size

Nominal designation and family transcribed from the live directory on 2026-10-19; unit conversions are calculated using exactly 25.4 mm/in. No matching drill row has been reviewed for this exact size. Paid standard limit tables have not been reviewed.

ASME B1.1 · standard scope ↗ · Full source scope →