Metric vs SAE Hardware

SAE (inch) and metric fasteners use completely different thread pitches and diameters. A 1/4-20 bolt is not the same as an M6 — and forcing one into the wrong nut will strip threads and ruin both parts.

Quick identification: SAE bolts use fractional sizing (1/4, 5/16, 3/8) with TPI (threads per inch). Metric uses millimeters and pitch in mm (M6 × 1.0, M10 × 1.5).

When sourcing replacement hardware on equipment built outside the US, assume metric unless you measure otherwise. Our team can ID an unknown fastener if you send a sample or photo with a scale reference.