135 or 118 Drill Sharpening Angle

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TonyL

TonyL

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I have both 118 and 135 degree bits and a Drill Doctor that I use to sharpen them (and sometimes change the cutting angle).

In general, what angles do you like:

  • For most soft woods?
  • Hardwoods?
  • Commercial High Pressure AA?
  • Homemade Mixed Materials?

    I did find much on the subject on the Internet, but wanted to solicit your opinions.

    Thanks!
 
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I've noticed that a lot of drill bit manufacturers like to tout the 135 degree angle with a split point for metal work, but this should also work good for manmade materials as well.

118 degree is generally used for multi-purpose stuff, and woodworking, but split points would be a good idea here too. It's a little more aggressive, removing the softer materials faster, and thus drilling through it faster.
 
135 degree great for wood & plastic, some folks claim 140 degrees much better, but in reality point angles all about compromises! Other factors such as lip relief angle and spiral important too!

Others would say Parabolic drill bits or Pilot/Bullet point bits so much better for myriad of good reasons.

JMHO, either twist drill bits or brad point bits most economical!
 
Thank you very much. I think I will retain the original angle. I have enough bits in both angles to choose what I want. Thanks again.
 
I prefer 135 degree split point for wood, plastic, and metal. I've reground my 118 degree bits accordingly. If you're using a Drill Doctor to make split points, read the instructions closely. The relief angle for split points is different.

Regards,
Eric
 
Showing my ignorance on the subject here but for non metallic drilling can you really tell any difference between drill °'s?
 
I am not sure. If my Drill Doctor didn't allow for more than 1 angle, I wouldn't even know there was more than one angle. How is that for ignorance :-).
 
Sabaharr said:
Showing my ignorance on the subject here but for non metallic drilling can you really tell any difference between drill °'s?
Click to expand...

As I mentioned, the 118 degree angle is for faster, more aggressive, removal of material, and doesn't work as well with harder material. You get a lot more wear and tear at the very tip of the bit, when drilling harder material, and it will need resharpening more often if you misuse the bit.

Between two identical bits ground and sharpened at both angles, you'll drill and clear your holes in softwood and the softer hardwoods faster with the more aggressive bit.

You will have less tearout in plastics with the less aggressive bit, and less blowouts as well.
 
A nice read explain why say lip & spiral/twist as important and drill bit angle. Much too technical for me think a sharp drill bit and chip clearance secret to drilling pen blank regardless of material.

DRILL POINT GEOMETRY by JOSEPH MAZOFF

If drilling a blank for Long Click or Artisan Clicker pen kits might want to consider a parabolic bit because; parabolic drill bits are most often used for deep hole drilling, parabolic drill bits drill holes faster than other drill models, parabolic spiral allows chips to flow up quickly, not blocking the hole or requiring frequent drill bit withdrawal to clean out wood chips. Parabolic drill bits rarely shred the area surrounding entry and exit holes, leaving less damage to be corrected after drilling. Downside to good parabolic drill bits is cost! Own only one bit cost me $6 and did not become a fan of them.

I used a brad point bit for Long Click pen and had no problem!
 
I should point out that if you're just occasionally drilling a hole in softer woods, 135 degrees is more than adequate. You'll drill a tiny bit slower, but the holes will be a little cleaner and you'll have to clear your flutes a little more often, but the bits will certainly last longer between sharpenings as well.
 
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