You know what the allen key size is but you are unsure what thread size you need to order? This tool can help, because by selecting either a metric or imperial key size, the tool will display the screw sizes for that key. To get the best match you do need to make sure you have identity the key as either metric or imperial, it can’t be both, because some sizes are close e.g. 3/16” and 5mm can be easily misidentified resulting in possibly ordering the wrong screw size.
Select a Socket Screw Size to see Matching Key SizeMetric
Metric Thread Size
=
Socket Head Cap
Low Head Cap Socket
Button Head Socket
Countersunk Socket
Set Screw (Grub) Socket
Shoulder Screw Socket
Imperial
Imperial Thread Size
=
Socket Head Cap
Low Head Cap Socket
Button Head Socket
Countersunk Socket
Set Screw (Grub) Socket
Shoulder Screw Socket
Select a Allen Key Size to see Matching Socket Screw SizeMetric