Just bent a drill bit

[Sutol]

Drilling a ball bearing (4" diameter ) whilst making a Trophy for a friend who has just written his Vauxhall VX220 off

The drill was cooled during the drilling operation but not enough as the end snapped off the bit whilst drilling about an inch in and the bit caught in the hole and started spinning the ball bearing which was slightly out of true on the bit. Before I could hit the off button on the stand drill, the bit bent as it was so hot and the ball spun it into the shape below.

The upside is that the bit is gaurenteed for life so I'll just post it back and they will send me a new one FOC

 

[jimmyj]

Why that's perfect for drilling around corners!

 

[Craig Clayton]

Where did you come across a 4" dia. ball bearing? Did you cramp it down in a good vise? You must have tempered the steel or you would not have even scratched it. You might not get warranty on the twist drill.
Here is some fun on terms .
I used cramp = clamp
As per mudwings = fenders
mudwing flaps = mudflaps

We just had a Roundabout constructed at a local intersection. Everybody was very cautious at first but it works well.
The ONLY PROBLEM IS I AM STILL GOING AROUND AND AROUND WAITING FOR A SPOT TO GET OFF.

Craig Clayton

 

[Sutol]

Where did you come across a 4" dia. ball bearing? Did you cramp it down in a good vise? You must have tempered the steel or you would not have even scratched it. You might not get warranty on the twist drill.
Here is some fun on terms .
I used cramp = clamp
As per mudwings = fenders
mudwing flaps = mudflaps

We just had a Roundabout constructed at a local intersection. Everybody was very cautious at first but it works well.
The ONLY PROBLEM IS I AM STILL GOING AROUND AND AROUND WAITING FOR A SPOT TO GET OFF.

Craig Clayton

Dont know where the ball bearing came from but we had two of them

A DeWalt drill bit which usually drills anything wouldn't even scratch it.

The bit I used is from a set that I have and the bits will drill stone or steel and will drill through a bearing case with no problem. They are gaurenteed for life against breaking or wearing out.
This one drilled into the ball about an inch before it broke, I didn't have it clamped and I was squirting lube on it with one hand and pulling down on the lever with the other so it may have shifted a bit under the drill.
Job done though
If it wears away though sharpening or breaks then it will be replaced free of charge, only thing is if you loose it you wont get a new one.

 

[Sutol]

We love roundabouts, some are called Islands, we have mini ones as well

Heres a pic of the unfinished Trophy with the rod soldered in ready for fitting a broken piece of alluminium wheel on top

 

[Craig Clayton]

I did a quick search and I found the following posts on a Practical Machinist site. They are comments as I found them.

( I have done this by putting them in the fireplace coals and taking them out the next day. I drilled and tapped them with no problems. )

( I have some 7/8 or 1" ball bearings, I want to drill a 1/4 inch hole half way into them.
What are my options?
I havn't tried heating them up first to see if that will soften them, would that work)

( just bring em up to a dull red and let em cool.
then use a cobalt bit, and they will drill right thru, just keep em cool and steady pressure.

i have done it many times for spinner knobs, and just to prove it can be done.)

I recently had to do a job involving drilling into hard bearings/bushings. One had a series of holes 2mm diam x 30mm deep!

(Get a Hi-Roc drill, I think they are made my MA Ford. They are carbide, straight flute. I had no problem drilling Rc64 with them. Tool life was short (about 10" of drilling on 4mm drills), and they aren't cheap, but what a beautiful hole.
It sounded like someone swinging a cat by his tail- but you cannot argue with the results. Flood coolant, and clamp your axes if you are in a b'pt or the like. )

If they are made by Dewalt are these drills carbide tipped for concrete.? When used in concrete would you set the drill to hammer. I have used resharpened concrete bits to drill hard steel but not hardened.

Craig Clayton

 

[crazyal]

On his many road trips to Florida my father loved deals. He came back one time with about 20 1/4" drill indexes (from China). He bought all of them for $10. Not sure why because he rarely drilled anything. I would use them for wood thinking that they could at least do that. Well I was wrong. While drilling some hard wood one of them untwisted itself then twisted it in the reverse direction. The $10 may have been a total loss as far as bits go but the laughs we had were worth it.

 

[jimmyj]

While drilling some hard wood one of them untwisted itself then twisted it in the reverse direction.

Brilliant! And that, my friends is what we should aspire to in our industry. Disposable crap.

Serously, that's funny.:laughing:

 

[s219]

I work for the fed government. Early in my career, I was working on a model, and got a new bit out of the cabinet. It bent like a nail. The next one untwisted like a twizzler. I figured it was low-bidder stuff. Likely was never heat treated at all.

 

[k0ua]

On his many road trips to Florida my father loved deals. He came back one time with about 20 1/4" drill indexes (from China). He bought all of them for $10. Not sure why because he rarely drilled anything. I would use them for wood thinking that they could at least do that. Well I was wrong. While drilling some hard wood one of them untwisted itself then twisted it in the reverse direction. The $10 may have been a total loss as far as bits go but the laughs we had were worth it.

So OK.. maybe good for marshmallow work? You know when you drill holes in them for putting a string thru to hang on the Christmas tree, Or am I thinking about popcorn? Well anyway, maybe they were just good for a laugh....

James K0UA

 

[dstig1]

Drill bits are hardened and break - they don't bend. You don't have actual drill bits there, they just look like it... Never seen a drill bit bend like that without breaking.

 

[CharlieS]

............... Before I could hit the off button on the stand drill................

On another and more serious note, this is a good example of why one should use a foot switch on some tools. Just sayin.......

 

[moored4]

Drill bits are hardened and break - they don't bend. You don't have actual drill bits there, they just look like it... Never seen a drill bit bend like that without breaking.

X2 - 40 years a millwright and never saw it happen. Thanks China!

 

[Willl]

"Just bent a drill bit"

Don't ya mean "Just 'broke' a drill bit" ? :laughing:

 

[Sutol]

Just like to point out that my bent drill bit has done a lot of work in the past year that I have owned the set. (british made btw)

Also that my bent drill bit did drill an inch deep hole into a hardened steel ball bearing which my other drill bits would not even scratch.

You will notice that the end of the bit has snapped off leaving the peice inside the ball.

Probably my fault for not securing the ball before drilling but hey...it did the job and I'll get a brand new drill bit to replace it.
The drill bit was dragged out of shape by the ball spinning out of true on the end of it after the bit snagged and jammed in the ball.
I can only think that the bit was so hot that its shaft was softened allowing it to deform after the hardened cutting edge had snapped off.

Unless anyone has a better explanation:anyone:

 

[SPYDERLK]

Just like to point out that my bent drill bit has done a lot of work in the past year that I have owned the set. (british made btw)

Also that my bent drill bit did drill an inch deep hole into a hardened steel ball bearing which my other drill bits would not even scratch.


I can only think that the bit was so hot that its shaft was softened allowing it to deform after the hardened cutting edge had snapped off.

Unless anyone has a better explanation:anyone:

Bound to have been a carbide tipped bit.
larry

 

[Short Game]

Guaranteed to bend or break as the situation requires. :confused2:

 

[forgeblast]

Just wondering what are the drill bits to avoid and which one are the good to best ones
for drilling metal (say steel, 1/8-1/4 thick).

 

[Craig Clayton]

To forgeblast
You should be able to buy good quality in PA. The good stuff is out there for the professional but so is the price in both countries. The trick is to get a balance between price quality and service. My Grandfather was a Tool and Die Maker and I have a collection of drills some more than 50 years old. But as in everything there is always a OOPSS FACTOR especially in a more powerful hand drill, it jams and your wrist twists.
If you buy the VERY VERY BEST set you could be drilling a door jam to plastic moulding or 1/4" steel. (OOPSS)

Craig Clayton

 

[deereman75]

Dormer drill bits are often thought of as some of the best.