M6 Bolt Size and Thread Specifications

Q: What drill size should be used for tapping M6 threads?

For M6 x 1.0 coarse thread, use a 5.0 mm tap drill. Use the Tap Drill Calculator for other pitches.

M6 is one of the most common metric fastener sizes. It is used in machinery, automotive assemblies, electronics, furniture, and general hardware where a 6 mm nominal diameter and 1.0 mm coarse pitch provide a strong, widely available thread.

Specifications

Specification	Value
Nominal diameter	6 mm
Standard pitch	1.0 mm
Fine pitch	0.75 mm
Tap drill size	5.0 mm
Closest imperial equivalent	1/4-20

Hex head size

Bolt size	Hex head size
M6	10 mm

Common uses

M6 bolts are common in machinery mounts, automotive brackets, electronics enclosures, furniture hardware, and structural components. They are widely stocked and compatible with standard M6 nuts and tapped holes.

Related tools

Metric to Imperial Screw Converter — convert M6 to 1/4-20 and other equivalents.
Tap Drill Calculator — get tap drill size for M6 and other metric threads.

Related charts

Universal Screw & Bolt Size Chart — metric, imperial, pitch, and tap drill in one view.
Tap Drill Chart — metric tap drill sizes including M6.

FAQ

What is the standard pitch for an M6 bolt?

The standard (coarse) pitch for M6 is 1.0 mm. Fine pitch M6 is 0.75 mm.

What drill size should be used for tapping M6 threads?

For M6 x 1.0 coarse thread, use a 5.0 mm tap drill. Use our Tap Drill Calculator for other pitches.

What imperial bolt is closest to M6?

1/4-20 UNC is the closest imperial equivalent to M6 in diameter and typical use.

Related guide

Metric vs Imperial Fasteners