An early version of a Pratt & Whitney precision bench miller. circa 1910, with a traditional flat-belt drive countershaft unit. Later machines were available with improved transmissions including a geared, two-speed , self-contained countershaft unit that gave six speeds through a built-in two-speed gearbox - a device also used on the P & W Precision Bench Lathes - and an infinitely-variable speed unit that mounted beneath the bench. See below for illustrations of the 2-speed gearbox-drive unit.

The milling machine's table was identical in section to that used on the company's Precision Bench Lathe - so allowing accessories to be economically transferred between the two machines.