Cutting Bits Flashcards
What does heat do to a bit
makes them to hot to hold
affects the heat treatment of the bit (cutting edge becomes soft)
What should you do to prevent this
Keep a cup of water nearby and dip your bit in it frequently.
Side cutting edge
does majority of the cutting.
Front cutting edge
Cuts when tool is advanced into the part
Nose radius
critical part for cutting edge, produces the surface finish
side rake
produces side cutting edge
side relief
provides your clearance for the side cutting edge. Without the relief the side cutting edge would hit the piece and not penetrate it.
back rake
Produces the front cutting edge
Angle for side relief
10*
Angle for Back and side rake
about 12* for side and 8* for back rake
Angle for front relief
8-10*
Nose radius types
small radius allows for tight corners
large radius produces better finish.
what is cutting speed
the distance the work moves past the work
feed
distance the cutter moves lengthwise during a single revolution.
using coolant allows the increase of feed by 50% and by 300-% by carbide cutters.
front relief
produces the front cutting edge
When and how was carbide discovered
In 1893 when trying to make artificial diamonds
Advantages of using carbide bits
better surface finish faster machining cuts tougher metal such as carbon and stainless longer working life can run 8x's faster than HSS no need for duplicate tools
Disadvantages of Carbide bits
more expensive
not easily shaped or sharpened
not as tough as HSS
more brittle than HSS
Common uses for carbide
lathe bits for turning
used in milling machines
saw blades
drill bits
