Which Allen Key should I use for the Socket Screw I am using?

We are often asked what size hex Allen key wrench will fit a certain socket screw. Below is a conversion chart to help:

Metric Socket Cap Screws

Thread Diameter Size Allen Key Wrench Size
M2 1.5
M2.5 2.0
M3 2.5
M4 3.0
M5 4.0
M6 5.0
M8 6.0
M10 8.0
M12 10.0
M14 12.0
M16 14.0
M20 17.0
M24 19.0
M30 22.0
M36 27.0
M42 32.0
M48 36.0
M56 41.0
M64 46.0

Metric Socket Set (Grub) Screws

Thread Diameter Size Allen Key Wrench Size
M2 0.9
M2.5 1.3
M3 1.5
M4 2.0
M5 2.5
M6 3.0
M8 4.0
M10 5.0
M12 6.0
M14 6.0
M16 8.0
M20 10.0
M24 12.0
M27 14.0
M30 14.0
M36 17.0

Metric Socket Button Screws

Thread Diameter Size Allen Key Wrench Size
M3 2.0
M4 2.50
M5 3.0
M6 4.0
M8 5.0
M10 6.0
M12 8.0
M14 8.0
M16 10.0
M20 12.0
M24 14.0

Metric Countersunk Socket Screws

Thread Diameter Size Allen Key Wrench Size
M3 2.0
M4 2.50
M5 3.0
M6 4.0
M8 5.0
M10 6.0
M12 8.0
M14 10.0
M16 10.0
M18 10.0
M20 12.0