4.9Mm Jobber Drill Bit - Silver Series

Product Description

 Alpha Silver Series 4.9mm 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 Click here to find your closest Alpha Distributor. TECHNICAL DATA Overall Length 86mm Flute Length 52mm Stainless Steel RPM 815 Tool Steel RPM 1222 Cast Iron RPM 1630 Malleable Iron RPM 1833 Medium Carbon Steel RPM 2037 Free Cutting Steel RPM 2852 Alum, Brass, Plastic RPM 4074 Wood RPM 6112 Feed per RPM (mm / rev) .15-.25 Standard pack Qty 10 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.