This post provides more detail on Wheeler's Patent countersinks.
It is not hard to find this countersink. The hard part is
finding the depth gauge that attaches to it.
Asa Wheeler of Brattleboro patented the countersink on April
12, 1870 and it was issued Patent Number 101,796. The following
year, 1871, Wheeler patented the depth gauge for his
countersink. It was issued Patent Number 116,901, issued on July
The first photo shows representative specimens I pulled from my
This is a representative array of Wheeler Patent countersinks.
The specimen on the left is the first issue of the tool and is
imprinted with the 1870 patent date. The second specimen shows
an original 1870 tool with the depth gauge patented in 1871. The
first gauges were cast in brass. The third specimen is a later
production that has no patent imprint and has a thumbscrew for
attaching it to the shaft.
Here is a detailed photo of the known kinds of depth gauges for
Wheeler Patented countersinks. Each depth gauge is a different
shape but all fit in the cutting slot in the head.
These are Wheeler Patent countersinks by later makers.
Apparently, when Wheeler's patent expired, Stearns
and Stanley started making them.
The top specimen is imprinted with, "Stearns". Note that the
middle specimen is imprinted "G. B. Wheeler", not Asa Wheeler,
the patentee. The bottom specimen is a Stanley production and is