What is the best way to extrude (remove) part of a shaft and leave a key

TimLesch

The goal is to extrude (remove) a small amount of a shaft as an insert but leave a key for alignment. I can't figure out the key part.

NeilCooke

You want to create a keyway and a key? Once you’ve removed the keyway material, just create another sketch (or reuse the existing one) to create the key. Make sure you use the “New” option when extruding the key. 

NeilCooke

You want to create a keyway and a key? Once you’ve removed the keyway material, just create another sketch (or reuse the existing one) to create the key. Make sure you use the “New” option when extruding the key. 

Jake_Rosenfeld

@TimLesch

You can also extrude the key as a "New" and then use Boolean feature (with keep tools box checked) to subtract the key from the shaft (optionally with some offset) to create the keyway without deleting the key.

https://cad.onshape.com/help/Content/booleanparts.htm

brian_brady

Keep in mind that keys are not like to be the same size as the slot. I am not talking as much about the cross section, but the length of the key and slot. If the slot is blind the ends will be rounded but the key will probably be square.