Alpha Black Series 12.5mm Jobber Drill Bit
DRILL FEATURES
- Tempered black oxide finish reduces friction between bit and workpiece
- 118 degrees split point for precision hole starting
- Fully ground premium quality M2 HSS
- Corrosion resistant finish
- Ideal for drilling hard metals (coolant recommended)
- Not recommended for soft materials or non-ferrous metals
- Available in common metric, imperial and panel/stub sizes.
- Clamp the work piece securely
- Select the correct speed and feed
- Use an appropriate coolant or lubricant
- Ensure the shank is securely held. Aviod 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.
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TECHNICAL DATA
| Overall Length | 151mm |
| Flute Length | 101mm |
| Stainless Steel RPM | 306 |
| Tool Steel RPM | 458 |
| Cast Iron RPM | 611 |
| Malleable Iron RPM | 688 |
| Medium Carbon Steel RPM | 764 |
| Free Cutting Steel RPM | 1070 |
| Alum, Brass, Plastic RPM | 1528 |
| Wood RPM | 2292 |
| Feed per RPM (mm / rev) | .25-.35 |
| Standard pack Qty | 1 |
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 :
