Metric Thread Pitch

With thanks to boltdepot.com

Bolt Diameter Standard Thread Pitch (mm) Fine Thread Pitch (mm) Extra Fine Thread Pitch (mm)
4mm 0.70 - -
5mm 0.80 - -
6mm 1.00 - -
7mm 1.00 - -
8mm 1.25 1.00 -
10mm 1.50 1.25 1.00
12mm 1.75 1.50 1.25
14mm 2.00 1.50 -
16mm 2.00 - -
18mm 2.50 - -
20mm 2.50 - -
24mm 3.00 - -
Size Identification: Metric bolts are written down as an "M" followed by 3 numbers. For example M10x1.25x35 The first number is the diameter, the second the thread pitch, and the third the length all in millimeters. The example is therefore a 10mm diameter fine thread bolt 35mm long.
Thread pitch: The distance from one thread to the next, measured down the length of the fastener.