Which Chisel Type is used for Cutting Key Ways, Grooves and Slots?

Answer - Cross Cut Chisel is used for Cutting Key Ways, Grooves, and Slots.

Cold chisels come in four basic varieties. The most popular variety of these is the flat chisel, which is used to cut sheet metal that is too thick or challenging to cut with tin snips, as well as bars and rods to reduce surfaces. Slots and grooves are cut with a cross-cut chisel. To allow clearance, the blade becomes narrower behind the cutting edge. 

For cutting semi-circular grooves for oil channels in bearings, a round nose chisel is employed. The diamond point chisel is used to remove center punch marks that were improperly positioned for drilling and to tidy up corners and other tough areas. Hence, Keyways, grooves, and slots are cut with a cross-cut chisel.

Summary:

Which Chisel Type is used for Cutting Key Ways, Grooves, and Slots?

A cross-cut chisel is used to carve out keyways, grooves, and slots. The blade gets narrower behind the cutting edge to make room for clearance.