Twist drill (4834)

Ruko twist drills with grindings and sharpenings according to DiN 1412

• Form N: Conical surface grinding normal-ground
Application: For all usual drilling work in steel, non-ferrous metals and plastics. The point angles depend on the machinability of the materials.
Advantages: Strong main cutting edges, insensitive to impact and lateral forces. Simple manual sanding possible.
Disadvantages: Wide cross cutting edge requires high feed force.


• Form A: Sharpened cross cutting edge
Application: For all usual drilling work on drills with a strong core, for large drill diameters for drilling into full material.
Advantages: Good centering when drilling by shortening the cross cutting length to 1/10 of the drill diameter and reducing the feed force.
Disadvantages: Additional grinding work.


• Form B: Sharpened cross cutting edge with corrected main cutting edge
Application For drills for steels with high strength, for manganese steels with more than 10 % Mn, for hard spring steels and for reaming.
Advantages: Insensitive to impact, one-sided loading and lateral forces. No hooking into thin-walled workpieces.
Disadvantages: High feed force, tendency to run, additional effort during regrinding.


• Form C: Cross section
Application: For drilling in grey cast iron, malleable cast iron and forgings.
Advantages: Protection of the cutting edges by extended main cutting edges, insensitive to impact, good heat dissipation - thus improved service life.
Disadvantages: Additional effort during regrinding.


• Form D: Ground joint for grey cast iron
Application: For drills with a very strong core for particularly tough, hard materials and for deep hole drills.
Advantages: Good centering, low feed force. Improved chip transport due to chip distribution.
Disadvantages: Perfect regrinding only possible by machine.


• Form E: center tip
Application For drilling sheet metal and soft materials, for blind holes with flat bottom.
Advantages: Good centring, low burr formation when drilling through, exact drilling in thin sheets and tubes, no hooking in. Available from Ø 2,5 mm.
Disadvantages: Sensitive to impact and one-sided loading. Perfect grinding only possible by machine.

Other ground sections and sharpenings

• Form U: special ground joint Application For drills with stable, automation-compatible profile, narrow groove with strong core.
  Advantages: Very good self-centering behaviour with application of highest cutting values. Short chips due to concave cutting.
  Disadvantages: Requires additional effort for regrinding.
  

If you have any questions, we will be happy to advise you in detail. Our support is available via phone and email on weekdays. Ruko twist drills with a large selection thanks to the full range available from the main catalogue.