Different styles of cutterheads for woodworking made on a mill drill.
The obvious ones are reworked (bored) sears cutterheads used on a shaper.
The indexible lug back knives/vise grip head is a match set made for
running flooring.  Sharpened by regrinding face only, profile remains
unchanged between set ups.  Other patterns show using low or negative hook,
made for running difficult wood on contour cuts without tearout.
smt