M10 vs 3/8-16 UNC Screw Size Chart

Overview

Technical specifications for M10 metric and 3/8-16 UNC imperial fasteners. These are often confused due to their similar diameters.

Comparison Table

StandardSizeDiameter (mm)Pitch / TPITap Drill
MetricM1010.00 mm1.50 mm8.5 mm
Imperial3/8”-16 UNC9.53 mm16 TPI8.0 mm (5/16”)

FAQ

Will an M10 bolt fit a 3/8-16 nut?

No. While they look similar, the M10 bolt (10.00mm) is physically too large to fit into a 3/8-16 nut (9.53mm). Additionally, the thread pitches are incompatible.

Source Standard

ISO 261 / ASME B1.1