Metal drills grind manually or by machine

The spiral cutting edges of a metal drill can be sharpened again and again. With practice and talent, this is possible freehand, but not always successful. Drill sharpeners are easy to use, even for beginners, but they are not always worthwhile.

Manual or machine

The art of grinding a metal drill is to precisely maintain the so-called point angle. It ensures that the cutting edges hit the material correctly during drilling. It is normally 118 degrees, it increases for harder metal wells. As an aid, there are holders in which the drill can be clamped and guided to the grinding wheel.

Drill sharpeners range from a grinder with a holder combination to fully automatic "sharpeners". In the cheaper combinations, which are available from about two hundred euros, the drill is fixed in the holder angle scale and guided to the grinding wheel. Fully automatic machines are similar to a pencil sharpener. The drills are inserted after selecting the appropriate angle and grind themselves.

Manual grinding manual

  • grinding machine
  • Grinding wheel made of silicon carbide
  • safety goggles
  • Possibly bracket

1st finger as a pivot bearing

Right-handed people place the drill in the first joints of the left index and middle fingers and fix the drill with their thumbs.

2. Guide the drill shank

With the index, middle finger and thumb of the right hand, grasp the drill shaft and bring it to the grinding wheel.

3. Press the drill

Press the drill bit down slightly and grind.

4. Turn the drill

After the ship of the first cutting edge and free surface rotated 180 degrees and again as before led to the grinding wheel.

5. Sand all edges

Apply the drill two to four times to have all relevant cutting edges ground.

Instructions for machine grinding

  • Drill sharpener
  • abrasive
  • Safety glasses when the machine is open

1. Clamp the drill

For open drill sharpeners, clamp the drill into the holder and set it up to the point angle.

2. Guide the holder to the grinding wheel

Move the holder to the grinding wheel according to the manufacturer's instructions. Usually there are hinges or guide rails.

3. Turn the drill

Either rotate the drill in the holder or re-tighten it by 180 degrees.

Tips & Tricks

If you're having trouble finding the exact tip angle of 118 degrees, you're tending towards a higher angle. This will sharpen the edge. At a lower angle, the cutting edge becomes dull.

Video Board: How to Hand Sharpen a Twist Drill