Sharpened drill bits don't last 5 seconds.

[atikovi]

I'm trying to drill out a broken M10 seat bolt with a half dozen drill bits from 1/16 to 1/4 inch. I use a Drill Doctor to sharpen them, except the smallest, but 5 seconds after I used them they are dull again. Are there some bits with hardened tips that can't be sharpened?

 

[PCustoms]

What's the bit look like?

I have a DD somewhere, used it 1x on my 1/2" drill and it totally fubared the angle and web. Nothing I did would make it run cut correctly after that.


Guess which bit I needed today? Lol

 

[Fcvapor05]

Sharpening a drill bit in a way that results in a sharp bit that hasn't had the edge temper destroyed (I.e. sharp and will stay sharp) is very difficult.

The bolt you're drilling is also likely to be very hard, which means if you're not using good quality bits, good luck.

Basically cheap bits that have been resharpened are not a good recipe for drilling success.

 

[larry_g]

Its a lot of work to properly drill a hole. Speeds, feeds, lube, right bit for the material your drilling and more. As far as losing it edge in 5 seconds makes me thing your using an inferior bit for the job at hand. You should be using a cobalt bit or better carbide. If your removing a broken bolt you should be using a left handed bit to give yourself a chance of catching the stub and backing it out..

AS far as the drill doctor. If you do not know what good grind looks like then your just hoping the machine is smarter than you are. Find a tutorial on drill bits and from there understand all the angles and clearances. Once you understand that then you can tell if your DD is doing what you want or if you need to tweak it a bit.

good luck

lg
no neat sig line

 

[atikovi]

Looks like I'll just buy some new bits. I'm about a half inch into the bolt and up to a 1/4 bit. Probably another half inch to go all the way through. Don't see the use of a left handed bit. If I couldn't get the bolt out with a socket, doubt it will come out with a bit. Probably have a better chance to drive it out the end in the forward direction if anything. Will probably tap it for an M8 bolt instead of trying to get it out.

 

[Legion Prime]

It's probably the drills themselves. What brand are they? 20 years ago I bought a 3/8 drill for work, think it was Irwin or VA. That put holes in more car bumpers than I could reasonably count. Every couple cars I'd give the shop foreman a dollar (less than a third what it cost new) to stick it in his DD. It's at least a good half inch shorter now than it was when I bought it but so long as you did your part when putting the drill in the chuck it cut as good as the day I peeled it out of the plastic, hell I probably still have it somewhere. However getting it seated properly in the chuck is critical. The DD is a fairly simple piece of equipment but not getting the drill seated properly in the chuck makes it totally worthless. Seriously go on youtube, watch a couple videos, and practice. It's not difficult to do nor is it difficult to mess it up. Make sure you do your part and the DD will do it's part.
Next find a set of Made in the USA drill bits. Look for Viking, Norseman, Chicago Latrobe, Cleveland, Atlas, Hanson, Ohio Drill & Tool to name a few. Make sure they are actually made in the US and don't just have "USA" or "America" in the company/product name. Most drill bits you find today are made in China/India/Brazil/Mexico from whatever metal they got a deal on last week and they might be heat treated, somewhat . . . sort of, maybe. Big box stores generally carry this cheap garbage.
My boss at work wanted to put a hole in some stainless tubing, had a brand new still in the package VA drill bit that he'd managed to make a dimple with after good minute+ of drilling. I went home, snagged my Hanson set I've had for years and zipped a hole right where he wanted it in seconds. The next week I found a great deal on a 10pc Viking set and ordered it for him. Some things it just doesn't pay to save a buck on. You can spend a pretty penny on drill bits, but you buy one quality set and you should rarely need to buy another drill bit again.

 

[Legion Prime]

Looks like I'll just buy some new bits. I'm about a half inch into the bolt and up to a 1/4 bit. Probably another half inch to go all the way through. Don't see the use of a left handed bit. If I couldn't get the bolt out with a socket, doubt it will come out with a bit. Probably have a better chance to drive it out the end in the forward direction if anything. Will probably tap it for an M8 bolt instead of trying to get it out.

A left hand drill bit can sometimes get a bolt out on it's own. The combination of the heat and the vibration combined with the counterclockwise motion can be all it takes to get it out. Not always but sometimes, you might be surprised.

 

[dalehsc]

We have a recall on the front fuel tank strap frame mount on Ram 1500's.
The drill bit provided in the original recall kit is now about 2 1/2 inches long.
it's been sharpened, many, many times & seems to be always chipped when I get it. To me with the right sharpening,speed & force, I can really turn out
some curly pigtails with it. There is the same size bit from Wurth, I've used it,but
return to the original every time.

 

[crugg65]

It’s not always possible but if you can heat that broken stud to weaken the temper to give you a better chance to drill it and maybe use those left hand drills like Larry said. I used the Drill Doctor quite often with very good success but read the manual that comes with it to properly restore your bits. Slower drill speed or using a variable speed drill is a must to prevent your drills from losing its edge!


Sent from my iPad using Tapatalk

 

[CJM8515]

All about the drill you use, the speed at which you drill and keeping the bit lubricated is key. I had similar issues trying to drill bed frames for a project till I realized that I needed to go slower and use better bits . That was when I was young and dumb and burnt up like 10 drill bits in a day before someone explained it to me and i took their advice.

 

[Lightning rod]

I use a DD all the time with no issues.
Probably not the DD or the way you are using it
Could be a hardened bolt. Like mentioned already
Go slow, use lube, and if possible , heat bolt to unharden it

 

[Professional Tool User]

Details such as what brand of drill bits you are using, whether or not you know how to use the DD properly, and what grade the bolt is would be helpful. Chances are either your drill bits are useless against hardened metal and/or your bits are not properly sharpened.

 

[PelicanPines]

Use your cobalt or solid carbide bits...

My DD 750 works just fine.

 

[PhysicsDude]

If you overheated the bit and ruined the heat treat of it, the drill doctor will sharpen it again, but it won't really cut since they aren't hard enough.

As others said, if you're drilling sharp, you'll want extra hard bits designed for metal such as Cobalt or Molybdenum bits.

 

[Joebass]

Sharpening a drill bit in a way that results in a sharp bit that hasn't had the edge temper destroyed (I.e. sharp and will stay sharp) is very difficult.

The bolt you're drilling is also likely to be very hard, which means if you're not using good quality bits, good luck.

Basically cheap bits that have been resharpened are not a good recipe for drilling success.

What???? I own a machine shop. Drills are HSS, and you can get them red hot, and it won't change the hardness.
Drill doctors are junk. Learn to sharpen by hand. Also most people don't follow the correct procedures and drill to fast or with not enough or too much down pressure.

 

[Joebass]

If you overheated the bit and ruined the heat treat of it, the drill doctor will sharpen it again, but it won't really cut since they aren't hard enough.

As others said, if you're drilling sharp, you'll want extra hard bits designed for metal such as Cobalt or Molybdenum bits.

This is false too! Any HSS drill will drill through metal( maybe not Chinese ****) and What is a molybdenum bit?

 

[Joebass]

As for real world advice from a professional, use made in the US drills, drill straight and with the correct RPM for the drill. Cobalt drills arent any harder, they are tougher and are for stainless mostly. Left hand drills work better for broken bolts and studs. As for the hardened bolt theory, I've drilled and turned lots of grade 8 and socket head cap screws on the lathe with plain old US made HSS bright or black oxide finish drills. Also drilled and tapped ton of stainless with HSS drills. Also they are drills not drill bits, and are used in a drill press, milling machine, lathe or drill motor.

 

[matt_i]

Solid carbide drill bit in a handheld tool is a recipe to buy a new solid carbide drill bit.

I would only use a solid carbide drill bit in a fixtured setup on a machine.

Its possible there's a hard case in the bolt due to too much heat generated during previous operations. Carve that out with a dremel tool's dental burr and then you can get back to HSS drilling.

 

[gnpenning]

What???? I own a machine shop. Drills are HSS, and you can get them red hot, and it won't change the hardness.
Drill doctors are junk. Learn to sharpen by hand. Also most people don't follow the correct procedures and drill to fast or with not enough or too much down pressure.

I agree about speeds and feeds. Makes all the difference in the world.

When DD first came out I bought one and couldn't get a drill as sharp as I could by hand, I was wasting to much time trying, so I put it away. Years later I came across the DD and watched several videos and tried again. As simple as they are I still couldn't match what I could do by hand. Plus it was faster to sharpen by hand for me. I never spent the time with the DD to see what was off. I know many are happy with them and happy for them. For me I'll hand sharpen. Speeds and feeds

 

[larry_g]

Another thing that may help you is to get screw machine drill bits. The shorter bits are stiffer and for me do a bit better.

lg
no neat sig line

 

[bmxr4life87]

Make a pilot hole with a small cobalt or similar hardness quality drill bit then just work your way up. The most important thing is to use slow steady pressure to get the pilot hole drilled then the rest is gravy

 

[Indexmill]

Steel bed frame angles are a mutherf*cker to drill.

 

[cvairwerks]

I've drilled out hundreds of hardened fasteners, including titanium ones, with HSS, cobalt and carbide bits, all by hand. Good technique and taking your time works. If you are not making long chips, speed and feed pressures are not correct.

Bed frames are made from mixed scrap, so there is no consistency in them.

 

[seber]

I finally figured out the Drill Doctor but it took about 80 mistakes to do it. Once you get it right, there is no one out there who can do as well by hand. On the other hand, if you don't take the time to figure it out, you get the problems the OP is having. I respect machinists who can hand sharpen but that takes a lot more time to learn than does the Drill Doctor and the results just aren't worth it.

 

[American Locomotive]

This is false too! Any HSS drill will drill through metal( maybe not Chinese ****) and What is a molybdenum bit?

It's an M10 seat bolt in a car, likely grade 12.9. A grade 12.9 metric bolt can be up to 44 HRC. That won't be the easiest material to drill by hand with HSS. Very possible yes, but you're going to need a lot of tool pressure and take your time - something that's pretty difficult with a hand drill.

Even a standard everyday drill press has around a 1:10 force amplification at the quill. Just 10 pounds of force at the handle will generate over 100 pounds of force at the drill. Trying to do that with a hand drill, inside a car, is just about impossible.

 

[bwringer]

It's an M10 seat bolt in a car, likely grade 12.9. A grade 12.9 metric bolt can be up to 44 HRC. That won't be the easiest material to drill by hand with HSS. Very possible yes, but you're going to need a lot of tool pressure and take your time - something that's pretty difficult with a hand drill.

Yep, that's a VERY hard bolt, and it's in a car interior. And it has some serious thread locker. Sure, heat could help, but that's also a great way to set the inside of the car on fire.

I'd get a new cobalt bit and use lubricant. You'll need to figure out some way to keep the lube away from the carpet. The good stuff like Tap Magic is especially stinky.

I most certainly would not even consider downsizing to an M8 bolt. This is a critical safety item.

 

[atikovi]

Picked up Milwaukee 7/64 and 7/32 cobalt bits at HD. Tried the 7/64 for 2 minutes with some cutting fluid and can't see any progress. Will keep at it or try the larger one.

 

[American Locomotive]

Push hard and use low speed. You could possibly be work hardening the bolt.

 

[mowkep]

It’s not always possible but if you can heat that broken stud to weaken the temper to give you a better chance to drill it and maybe use those left hand drills like Larry said. I used the Drill Doctor quite often with very good success but read the manual that comes with it to properly restore your bits. Slower drill speed or using a variable speed drill is a must to prevent your drills from losing its edge!


Sent from my iPad using Tapatalk

What he said...sounds like your rpm is too fast.

 

[mc4life27]

I'm trying to drill out a broken M10 seat bolt with a half dozen drill bits from 1/16 to 1/4 inch. I use a Drill Doctor to sharpen them, except the smallest, but 5 seconds after I used them they are dull again. Are there some bits with hardened tips that can't be sharpened?

Sounds to me you need to do some research on how to drill out a harden bolt and stop thinking you know everything and stop thinking you know how to drill correctly. Try and relearn your technique. Try and learn with an open mind.


Sent from my iPhone using Garage Journal

 

[oldmachinenut]

I've drilled out hundreds of hardened fasteners, including titanium ones, with HSS, cobalt and carbide bits, all by hand. Good technique and taking your time works. If you are not making long chips, speed and feed pressures are not correct.

Bed frames are made from mixed scrap, so there is no consistency in them.

Most of the bed frames are re-rolled railroad rail from Jersey Shore Steel in central Pa. and it is a drill bit destroyer,

Bill

 

[xman_charl]

agree about bed frame metal...sort of ify material

bed frames are cheap, easy to cut, good for support brackets

use them for holding fixtures on my bench top mill

have practiced welding on bed frame junk

use what I got

Charl

 

[ItsNemo]

Looks like I'll just buy some new bits. I'm about a half inch into the bolt and up to a 1/4 bit. Probably another half inch to go all the way through. Don't see the use of a left handed bit. If I couldn't get the bolt out with a socket, doubt it will come out with a bit. Probably have a better chance to drive it out the end in the forward direction if anything. Will probably tap it for an M8 bolt instead of trying to get it out.

Did everyone else miss this? Tap to M8? You think if you can barely drill it that you're going to be able to tap the thing too?

I'll wait for the update of you asking how to get your broken tap out of the hole

 

[Steve_P]

The Drill Doctor is not the problem- it's **** drill bits. I have a DD and use Norseman bits. No issues at all with either

 

[dutchgray]

Did everyone else miss this? Tap to M8? You think if you can barely drill it that you're going to be able to tap the thing too?

I'll wait for the update of you asking how to get your broken tap out of the hole

Especially considering the op said it was a seat bolt, assuming a road vehicle this is the kind of thing you don't want to have anything to do with. Best of staying out it.

 

[Milton Shaw]

I have seen some of the seat bolts that stick out the bottom side of the floor pan enough to put some vice grips on and screw it out from the bottom. Just a thought. If you are in the rust belt you may never back those threads out if they are rusted that bad on the bottom.

 

[atikovi]

They don't stick out the bottom.

 

[Ramblin Man]

I agree with what Milton Shaw said ,if that would have worked. That got me to wondering if welding a nut on the broken bolt would work.

Being careful not to set the car on fire, or weld it on from the bottom.

 

[Old Man Roger]

Push hard and use low speed. You could possibly be work hardening the bolt.

Exactly what I was thinking. People tend to use way too much speed and not enough pressure.

 

[atikovi]

This is what it looks like. Hole .40" deep.

7/32 cobalt bit won't go any further.

This is the other one where the bolt came out fine.

Would a solid carbide bit be next? Can they be used in a hand drill?