M3 Bolt Size and Thread Specifications

M3 is a small metric fastener used in electronics, small machinery, and precision assemblies. It provides a 3 mm nominal diameter with 0.5 mm pitch and is commonly used where space is limited.

Specifications

SpecificationValue
Nominal diameter3 mm
Standard pitch0.5 mm
Tap drill size2.5 mm
Closest imperial equivalent#4-40

Hex head size

Bolt sizeHex head size
M35.5 mm

Common uses

M3 bolts are common in electronics enclosures, small machinery, cameras, and precision equipment. They are also used in furniture hardware and light structural applications.

Related tools

Related charts

FAQ

What is the standard pitch for an M3 bolt?

The standard pitch for M3 is 0.5 mm.

What drill size should be used for tapping M3 threads?

For M3 x 0.5 thread, use a 2.5 mm tap drill.

What imperial screw is closest to M3?

#4-40 is the closest imperial equivalent to M3.