Alpha Silver Series 8.5mm Jobber Drill Bit
When you go to buy a drill bit, what are you needing ? Just a drill ? or do you actually want HOLES ?
DRILL FEATURES
M2 HSS Fully ground M2 HSS material increases drill life
118 Degree Split Point cuts faster and reduces wandering
TECHNICAL DATA
Overall Length 125mm
Flute Length 81mm
Stainless Steel RPM 448
Tool Steel RPM 672
Cast Iron RPM 896
Malleable Iron RPM 1008
Medium Carbon Steel RPM 1120
Free Cutting Steel RPM 1568
Alum, Brass, Plastic RPM 2241
Wood RPM 3361
Feed per RPM (mm / rev) .15-.25
Standard pack Qty 5
DRILLING PRACTICE
The flute form, web thickness and split point of the standard Alpha drills are suitable for most materials forming fine chips. For effective drilling, the rigidity of the drilland work piece are most important. The shorter the flute length the more rigid the drill. Long drills must be adequately supported to reduce vibration.
The following are important in drill use :
Clamp the work piece securely
Select the correct speed and feed
Use an appropriate coolant or lubricant
Ensure the shank is securely held. Avoid using worn drill chucks as the drill may slip during use.
Regrind the point or replace the drill before it dulls, do not force a worn drill.
When deep hole drilling, withdraw frequently to clear the chips ( deep holes start at 4X the diameter)
For stainless steel, manganese and high tensile steels, do not allow the drill to swell as it will cause work-hardening. Use a slower speed and heavier feed for these materials.