What type of drill bit for stud extraction?

[DROOPY209]

Tomorrow I am going to attempt to extract a broken exhaust manifold stud on my head, the upper one by cylinder #1.

The stud is broken flush with the head. All other 8 studs have been replaced with SS studs.

What brand/type/size/material of a drill bit should I use? The stud is 8MM. I have an E-Z out but I dont have a drill bit yet.

Which drill bit will drill into the stud the easiest? What other measures should I take when trying to extract this stud? Should the car be warm or cold?

The head/valvecover area by this stud is all black and ugly looking due to the stud not being there.

Thank you in advance for your help.

Jorge

 

[BOBS90TURBO]

Whatever you do, make sure you use a Tungsten Carbide bit, I tried several othet types and ended up breaking all of them, and having to dig them out with a Carbide dremmel bit.

 

[BOBS90TURBO]

If I was you, I would just get the Carbide dremmel bit and dremmel a hole big enough to get a good size eazy out in, get a torch and put heat on the broken stud for about 60 seconds before you back it out, Heat is the Key.Lots of heat,,,,

 

[DROOPY209]

So, should I use a tungsten carbide bit or a carbide dremel bit?

should I just drill into the stud centered?

Should any PB Blaster be involved?

 

[saiyansniper]

So, should I use a tungsten carbide bit or a carbide dremel bit?

should I just drill into the stud centered?

Should any PB Blaster be involved?

Honestly dude, just find a drill bit the right size and go to town. I've found the drill is a bigger liability than the bit, especially on battery powered setups.

 

[oldman]

Cobalt bits is what you need, make sure it's a starter bit so you don't need to to center punch against your alluminum head. Aim for the largest ez out while having enough left to keep the stud together, make sure you drill deep enough to prevent the tip of the ez out from breaking off, drilling through ez out is no ez task. Start from small bits and gradually work your way up, drill should be set at the lowest speed and oil/lubricant applied to the drill bit regularly to prevent overheating, let the drill do the job while you keep it perfectly centered. Take your time on this, you probably won't get a second chance if you wish to keep the original threading intact.

 

[tstkl]

ive got the same problem almost, but on the intake side. theres a little bit sticking out, but not enough to do something with it. someone told me the best thing to do is use a helicoil kit. it basically rethreads the hole once you drill it out. i think you like drill and tap the next size up, then put the helicoil in and it acts as the threading, so the outter diameter of the thread is actually the inner diameter of the thread you just drilled and tapped. maybe im wrong, but it looks like this is the f u way of doing it.

 

[my98GST]

Speaking of the devil, I was about to make the same thread. I have a EM stud that broke off about .25" inside the head

I'm scared of trying to remove it

 

[waylon]

Like Oldman said cobalt would be the best. Carbide drills would break with a hand drill. Would be very hard to get that out. Also i would start off going half the size of the bolt..just incase the ezout slips then you just go bigger. Get a good set of ez outs. Some like this should be good. take your time with it

http://buy1.snapon.com/catalog/item.asp?item_ID=10523&group_ID=1262

 

[DROOPY209]

I will be using a Makita electrical drill, not battery powered. It has several levels of speed.

Should my engine be warm when I start this?

I also have a torch as well, as someone mentioned heating the stud for a minute before extracting it.

 

[Eclipsethis90]

I am am machinist for the USMC and 90% of my job is pulling broken hardened studs out of aluminum housings. Oldman is absolutely correct in suggesting cobalt drill bits. Like Oldman said you don't want to centerpunch on the aluminum, it will bind/gall/ruin the threads. We use a dremel tool with a small Carbide Dental Burr bit to start the hole exactly center then go as deep as you can with your burr. Note, buy more than one burr because they break easily if you push to hard. Find a colbalt drill bit just barely bigger than the burr and drill ALL THE WAY THROUGH THE BROKEN STUD. In all the books and all the old time machinist tips that I've learned the hard way if you do not drill all the way through you will not release the "outer tension" on the threads. After stepping up your sizes and getting to the appropirate hole size for your easy out. I would suggest NOT using anything but a tap handle for your easy out. Cresent wrenches are about the worst thing to crank on an easy out with. If you have any questions PM me, I'll be more than happy to help.

 

[DROOPY209]

I attempted to extract the broken stud that is inside the head...that pesky upper exhaust manifold stud by the power steering pump.

It didn't work. I drilled and drilled, used wd-40, PB Blaster, and nothing. I got another drill bit and WHAM! it started to drill into the stud. When I drilled all the way, I took out the drill bit and put in the E-Z out. The E-Z out just spinned and spinned. That broken stud is in there good!

Next plan of action....I went down to NAPA auto parts and they wanted 40 bucks for a helicoil kit. I only need one helicoil insert. I said forget it....

My friends' family owns a Machine shop/performance engine shop. I'm gunna go over there and see if he will sell me a single helicoil insert. That is my only option now so that I can keep the hole the same size with the same pitch.

 

[Eclipsethis90]

Ensure if you get a helicoil, you get the tap for that specific coil because the taps for helicoils are not normal average sizes or thread pitches. So the easy out spun...hmm...did you tap it LIGHTLY with a hammer to get the threads to bite? Was there any oil on the stud when you tried the easy out? If so use a little brake parts cleaner to remove the oil. Also a few other reasons easy outs spin... they are too long and just barely hit the bottom of the hole (Solution: grind the tip back a little) or drilling a size too big will give you bad grip alsoand cause it to hit the bottom also. When i pull studs and bolts I might try 5 or 6 different size to see which gets the best bite. I would recommend to anyone that works on these cars to go buy a Snap On Easy Out kit, there is like 8 easy outs in there (if i do recall right ). That brand doesn't break as often and seem to not twist as much when you put load on them. I am not trying to advertise for them but i hate to hear about people spending a chunk of thier money on inferior tools. Like i said if anyone needs some new ideas on broken fasteners and how to fix them please PM me.

 

[Superbeast406]

I have a Snap On easy out kit. It contains 5 easy outs, and matching recommended drill bits. The cool thing is that the drill bits are reverse style. Sometimes the broken piece comes out with just the drill bit alone. Thats why I bought the kit, and would recommend a reverse style drill bit for any stud or bolt removal.

 

[wolf20043]

I attempted to extract the broken stud that is inside the head...that pesky upper exhaust manifold stud by the power steering pump.

It didn't work. I drilled and drilled, used wd-40, PB Blaster, and nothing. I got another drill bit and WHAM! it started to drill into the stud. When I drilled all the way, I took out the drill bit and put in the E-Z out. The E-Z out just spinned and spinned. That broken stud is in there good!

Next plan of action....I went down to NAPA auto parts and they wanted 40 bucks for a helicoil kit. I only need one helicoil insert. I said forget it....

My friends' family owns a Machine shop/performance engine shop. I'm gunna go over there and see if he will sell me a single helicoil insert. That is my only option now so that I can keep the hole the same size with the same pitch.

I know this sounds stupid, but were you running the drill in FWD or reverse with the easy out?
Mike

 

[BOBS90TURBO]

First of all Carbide is much stronger than Cobalt, And I have removed/fixed 20-25 broken studs, and I said to use a Carbide dremel bit to eat a big hole in the center of the stud so you can get a bigger e-z out inside. I have had several smaller e-z out's break off inside the stud and or Cobalt drill bits break, and then you HAVE to use a Carbide dremel bit to eat the hardened bits or E-Z out's away.. As far as the costs of a helicoil kit. If you can not get the stud to back out, ust carefully remove the stud with a small carbide dremel bit buy eating it away until you get to the actual 8mm head threads and then buy a 10mm tap and stud for about $5 bucks and just make some new bigger stronger threads(you may have to dremel the exhaust manifold hole a little bigger to fit over the 10mm stud, the stockers are 8mm. And remember the pitch is 1.25

 

[Eclipsethis90]

wolf20043 "I know this sounds stupid, but were you running the drill in FWD or reverse with the easy out?
Mike"

Wolf,
The drill bits superbeast is talking about is a left handed bit and needs to be run in reverse of the normal drill operation. As for an easy out in a drill......good luck if the stud is truly siezed in there. Like i said before a tap "T" handle works wonders.

 

[my98GST]

I know this is going to sound like a complete NOOB question but isn't running the drill in reverse going to eventually break the grip on the bit and it come undone??

 

[SlowSpyder]

I know this is going to sound like a complete NOOB question but isn't running the drill in reverse going to eventually break the grip on the bit and it come undone??

Drill bits that usually come with extractors or easy outs are left hand drill bits(run in reverse)

 

[sp00ln]

Tomorrow I am going to attempt to extract a broken exhaust manifold stud on my head, the upper one by cylinder #1.

The stud is broken flush with the head. All other 8 studs have been replaced with SS studs.

What brand/type/size/material of a drill bit should I use? The stud is 8MM. I have an E-Z out but I dont have a drill bit yet.

Which drill bit will drill into the stud the easiest? What other measures should I take when trying to extract this stud? Should the car be warm or cold?

The head/valvecover area by this stud is all black and ugly looking due to the stud not being there.

Thank you in advance for your help.

Jorge

*edit*

I typed up some advise, but then I read the thread and noticed you already tried to remove the stud. Best of luck

 

[waylon]

Yes Carbide is stronger, but cobalt can flex more.. thats why you should use a cobalt drill... if your using a hand drill... but yall are right about the dremel bit use that if you got it