These work extremely well but are
difficult to find. The first photo illustrates the total number
I could amass in 50 years.
This photo illustrates Lewis bits in a frontal
These bits have a lead screw on
their tips which effectively pulls them into wood to create a
screw pilot hole with a countersink at the wood surface.
This is a dorsal view of Lewis bits.
Only one of my Lewis ,bits is marked by a
It is imprinted, "SNELL" on one flat of the tang.