Abstract
Cutting-off tests were conducted on 2S and 56S round bars of about 40mm in dia. by holding the tool bit nearly around the centre of turning lathe.
If the tool bit was siturated in the higher position than the axis of rotation of the worked piece, cutting resistance gradually decreased with the increase of the depth of cut. This was caused by the fact that the actual rake angle in cutting grew gradually larger than that angle of tool itself with the approach of the tool to the centre. If the tool was set in the lower position, the resistance would grow in reverse.
The cutting resistance was calculated in consideration of the fact that the actual rake angle was affected by the vertical position of the tool bit. Then, it was shown that the calculated values corresponded well with the experimental values.
