139) For cutting acme threads, the threading tool should be ground to an included angle of

140) The tip of a cemented carbide tool is joined on the shank by

141) To cut 20 mm internal square thread with a pitch of 2.5 mm, the core diameter should be

142) Which one of the following materials for lathe cutting tools can be forged to any desired shape ?

143) Dovetail chasers are clamped in a