Americanmachinist 1190 13690retro0101j00000006624
Americanmachinist 1190 13690retro0101j00000006624
Americanmachinist 1190 13690retro0101j00000006624
Americanmachinist 1190 13690retro0101j00000006624
Americanmachinist 1190 13690retro0101j00000006624

Fast times

March 20, 2006
75 years ago in American Machinist
Machine tool manufacturers were producing machines designed specifically for the then-new tungstencarbidecutters in 1931, and the potential for the cutting grade was becoming evident, American Machinist editors said.

Machine tool builder Kearney & Trecker demonstrated a milling machine that featured a more rigid head and table than seen before, with a spindle that ran at speed-and feed-rates "well above average." Aluminum was machined with a 5-in. milling head at spindle speeds of 1,000 rpm (1,300 ft. per minute) with a 40 in. per minute feed rate and a 0.125-in. depth of cut. Working on a smaller cut, the machine trimmed the same piece, and demonstrated a rapid traverse rate of 240 ft. per minute. Onlookers compared the demonstration to cutting wood with a circular saw because the material was cut so fast. The machine produced an equally impressive result when it was used to cut cast iron, the editors said.