Hex wrench size chart

[mklotz]

I did not know about the SAE numbers. I just made a holder with every size hex wrench I have in it, in ascending order. SAE and metric. So if none of those fit, then I don't have the Allen key.

I think you've missed the point. The idea is to avoid the need to try successive wrenches for a fit. Assuming you know the specification of the SHCS or set screw, just look at the chart and select the wrench it shows.

For example, if you're using a 6-32 cap screw, the chart says you need the 7/64" hex wrench. A 4-40 set screw will require the 0.050" wrench.