LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
BORING BAR CUTTING TOOLHOLDER.
(2) High-Speed Steel.
High-speed steel is alloyed with tungsten and
sometimes with chromium, vanadium, or molybdenum. Although not as hard as
properly tempered carbon steel, the majority of lathe cutting tools are made
of high-speed steel because it retains its hardness at extremely high
temperatures. Cutter hits made of this material can be used without damage
at speeds and feeds which heat the cutting edges to a dull red.
(3) Stellite. These cutter bits will withstand higher cutting speeds than
high-speed steel cutter bits.
Stellite is a nonmagnetic alloy which is
harder than common high-speed steel.
The tool will not lose its temper,
even though heated red hot from the friction that is generated by taking a
cut. Stellite is more brittle than high-speed steel. To prevent breaking
or chipping, it requires just enough clearance to permit the tool