Far Tools TDM 400B, Manual, Page: 15 / 40

© FAR GROUP EUROPE
SHARPENING TOOLS
Note: The grinding head is the ideal tool for this operation. The grinding head may be
fitted with a green grinder (green silicon carbide) specially designed to sharpen carbide
tools
Never heat the carbide and cool it regularly in water
Always pass the carbide plate support part over a fettling grinder.
Metal carbides
WARNING: Always wear protective goggles while sharpening
(Cobalt, tungsten, titanium, boron combinations) These carbides that are obtained with
a special heat treatment called sintering, are used in the form of disks or “inserts”. The
latter are placed onto the tool body and attached by brazing using a special brazing
powder
LATHE TOOLS with metal carbide tabs
a, delivery angle.
. Characteristic angles: b, sharpening slope
(a+b+d=90°) d, cutting angle.
Angle values a and b
Metals and alloys to
be machined
/ Resistance R
kg/mm 2
Delivery
angle
a
Sharpening slope
t
Steel
up to 50 kg 6° 22 to 25°
50 to 60 kg 6° 18 to 20°
60 to 70 kg 6° 15 to 18°
70 to 80 kg 5° 12 to 15°
80 to 95 kg 5° 10 to 12°
Grey cast iron 6° 8 to 10°
Various bronzes 7° 5 to 6°
Aluminium 8° 25 to 30°
Chip breaker (Fig.2): When machining steel grades only, the tool cutting edge receives suitable
sharpening. The length l of the chip breaker varies according to the grade of steel and the pass
load:
For steel up to 50 kg/mm2.............. l= 3.5 mm
For steel of 55 to 75 kg/mm2.............. l= 3.0 mm
For steel of 80 to 95 kg/mm2.............. l= 2.5 mm
Remark. The depth or the height of the chip breaker does not vary, it is 0.5 mm (approximately).
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