Drill Bits Bending

[Garyg]

It doesn't seem what type of drill bit I use they seem to bend in the drill press or the lathe. Even large diameter 5/16 and greater bend.
They all seem to be made in China though.
I even use a center bit to start the hole.

 

[Micke S]

Check that the drill bit is perpendicular to the workpiece and that the drill bit is symmetrical at the end.

 

[kd4gij]

Witch drill bits have you tryed?

 

[JimDawson]

Maybe a little less pressure, more RPM? But could be an alignment problem, or just really crappy drill bits.

 

[Bill C.]

Try another brand. In the mean time take a small file and try filing a notch about half way up. If it cuts a notch then the bits were not harden properly.

I hate it when either drill bits or allen wrenches bend. I had allen wrenches end up looking like drill bits.

 

[G MORSCH]

I agree with Bill above. I bought a cheap set of drills a few tears back and the are totally soft. Stroke them with a file and see if they are hard. They may only be good for wood and even then you will get extra practice sharpening them.
HSS must lose something in the translation between English and their dialect.

Good luck!

Gary

 

[RJSakowski]

My wife bought some office furniture some years ago and I was pressed into service assembling it. The screws were button head with 5mm hex sockets. Each chair had a 5mm Allen wrench in the fastener packet and I was barley able to keep ahead of the wrenches as I assembled the ten chairs. "Lousy tools" I thought. When the assembly was done, A had a collection of 5mm wrenches. I decided to to a little experiment. I heated the wrench to a cherry red, until tit was no longer magnetic , then quenched in water. I polished the wrench to a bright finish and heated it slowly from the middle until I had a dark straw color at the business end. Guess what? It is now hard to a file and no longer twists in use.

Nothing wrong with the steel; they just do not know how to harden and temper.

Back to the original issue: bending drill bits. I have observed this when hand drilling because the drill spindle is not aligned with the hole being drilled. It usually precedes a snapped drill bit. Is it possible that the spindle is not aligned with the quill so the drill is being fed off axis? On a lathe, this would be indicative of a misaligned tailstock.

 

[rsegars]

I have had good results even with the made in China bits, but I always start with a center bit and have the lathe at a very slow speed and drill with smaller bits first and gradually work up to the size I want. Not to mention lots of cutting oil. I was drilling a barrel bushing today and decided to see if some of the mess could be avoided. I placed a paper towel under the part that was being drilled and changed to a fresh one with each larger drill bit. The cleanup was very easy. Hope this helps someone.

 

[Andre]

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

 

[RJSakowski]

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

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