M5 vs 10-24 UNC Screw Size

Overview

Technical specifications for M5 metric and 10-24 UNC imperial fasteners. These are two of the most commonly confused sizes in mechanical assembly.

Comparison Table

StandardSizeDiameter (mm)Pitch / TPITap Drill
MetricM55.00 mm0.80 mm4.2 mm
Imperial10-24 UNC4.83 mm24 TPI3.8 mm (#25)

FAQ

Is M5 the same as 10-24?

No. An M5 bolt (5.00 mm) is physically larger than a 10-24 bolt (4.83 mm). Furthermore, the thread pitches are incompatible (0.80mm vs 1.06mm pitch equivalent).

Source Standard

ISO 261 / ASME B1.1