M9 Bolt Size and Thread Specifications

What is an M9 bolt?

An M9 bolt has 9 mm nominal diameter with typical coarse pitch 1.25 mm. It bridges M8 and M10 but is less common in general hardware assortments.

M9 is an intermediate metric size that is not as widely stocked as M8 or M10. Always verify pitch and strength class against the original part. Spanish reference: perno M9.

Specifications

SpecificationValue
Nominal diameter9 mm
Standard pitch (coarse)1.25 mm
Fine pitch1.0 mm
Tap drill size7.8 mm
Closest imperial equivalentbetween M8 and M10

Hex head size

Bolt sizeHex head size
M914 mm

Common uses

Imported machinery, specialty equipment, and applications where documentation specifies M9.

Related tools

Related charts

FAQ

What is the standard pitch for an M9 bolt?

The common coarse pitch for M9 is 1.25 mm. Fine pitch is often 1.0 mm where specified.

What drill size should be used for tapping M9 threads?

For M9 x 1.25 coarse thread, use approximately a 7.8 mm tap drill. Use our Tap Drill Calculator for other pitches.

What imperial fastener is closest to M9?

between M8 and M10 is a practical reference for comparing M9 to inch hardware; verify fit for your application.

Sponsored