Broaching on the Lathe

[Toolmaker51]

Great job jjr2001. Times call for broaching without standard means. Cutoff blades are made in enough width/ height sizes to render most keyways. I can't say whether flat or hollow ground type work better. I do think flat tapered blades are stiffer than T's, helpful when goal is depth. A cutoff tool normal edge will shear, but found a hook [per broach or bandsaw tooth ] break chips best. Easy with an abrasive cut off wheel.
If possible, drill through part wall, perpendicular and just beyond end of keyway. When cutting blind, the relief lessens crowding.