This range of drills are high quality, not a use once and throw away
You pay for what you get
SS HSS DIN338 JOBBER DRILL
General-purpose drill, to drill steels with tensile strength up to 1.000 N/mm2, cast steel, grey cast iron, malleable cast iron, nickel brass and graphite.
A wide range of DIN 338 High Speed Steel Jobber Drills with a steam tempered finish for improved tool life
If you require packs of 10 or larger please email me for price
If you need a certain size drill please email and I will see if we can get it for you
Any size for any material
Drilling Practice
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The flute form, web thickness and helix angle of the standard drill are suitable for most materials producing semi-continuous chips.
Drilling sizes of 13mm and smaller in soft materials which produce continuous chips, e.g. copper, aluminium, a bright finish fast helix drill may be required to remove the swarf more effectively. Conversely on materials producing discontinuous chips like brass, gunmetal and some plastics, a slow spiral is preferable.
For effective drilling, the rigidity of the drill and work piece are most important. The shorter the flute length the more rigid the drill. Long drills must be adequately supported to reduce vibration, or stage drill as opposite.
Heavy duty thick web drills may be necessary on the more difficult materials, or when work lacks rigidity. These drills must be point thinned or have split points.
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The following are important in drill use:
1. Clamp the work-piece securely.
2. Select the correct speed and feed.
3. Use an appropriate coolant and lubrication.
4. When using a taper shank drill use a soft face hammer or wood block for insertion.
5. Ensure the shank is securely held. Avoid using worn sockets or drill chucks as the drill may slip during use.
6. Regrind the point before it dulls, do not force a worn drill.
7. Deep hole drilling, withdraw frequently to clear the chips. Deep holes start at 4 times diameter.
8. Opening out existing hole, do not use a 2 flute twist drill, use a 3 or 4 flute core drill. Pilot holes should be 1.5 times the chisel edge length.
9. Stainless, Manganese and high tensile steels, use an automatic feed throughout the drilling cycle. Do not allow the drill to dwell as it will cause work-hardening; use a slower speed and heavier feed than on easier machined materials.