Drill Bits Bending

[Andre]

Yes! I was under the impression that Gary was observing flexing, not a permanent deformation.

Now........ carbons steels will bend to some extent. I wonder if his were carbon steel.

I've REALLY reefed on a 5/16 drill, never had anything over say 1/8" bend while drilling.

 

[Charcole]

Real HSS bits would shatter before they bend (and hold a bend)!

Not necessarily. HHS and carbide drills do have some flexibility. On the longitudinal axis of the body and from compression. It's also why you see drills that are 10+ times diameters have more body clearance.

 

[chips&more]

Not necessarily. HHS and carbide drills do have some flexibility. On the longitudinal axis of the body and from compression. It's also why you see drills that are 10+ times diameters have more body clearance.

I’m not too sure about carbide drill bits flexing and compressing and still being in one piece after the fact? HSS drill bits can and will flex when not used correctly.

 

[Dave Smith]

make sure that your drill bits are sharp so they will drill without putting too much pressure on them---dull bits with excess force may want to flex----Dave

 

[lowlife]

I have a high quality Chinese bit around here somewhere. I kept it because it bent 90 degrees and didnt break.......I was very impressed.

 

[RJSakowski]

I have a high quality Chinese bit around here somewhere. I kept it because it bent 90 degrees and didnt break.......I was very impressed.

Must be a different manufacturer than the ones I have seen. Most chip or break at the mere sight of the work.

 

[X-RAY]

I had one actually untwist before. I'll have to see if I can find it and get a picture, it was pretty crazy looking.

 

[savarin]

I just purchased a packet of 10 bits 3.3 mm from ebay, only $3:00
Waste of time as every one is made slightly off centre, the point inscribes a circle approx 1mm.
They are not bent just made off centre.
Interesting as I've never seen that before.

 

[markknx]

If all else mentioned is not the issue be sure your Chuck does not have a lot of run out
Mark

 

[Garyg]

The drill bits bend/flex but spring back after pressure is taken off. My drill press does have a fair bit of run out but I try to use it where acccuracy is not a problem. The tail stock on the lathe is quite good but for some reason I never thought about the chuck. Everything seemed so tight. I will have to do some tests. The set of cobalt bits I bought do seem to be the ones I have the issue with now that I think about it. I hope not as it was a large set with all the numbered bits and the fractional ones.