weld a nut one size smaller to it and spin it out...

 

Anything that does not require welding?..

 

EZ OUT. Did you bottom it out in the hole?

 

Get a reverse style drill bit, start drilling a hole in the center. It will usually just spin out but if it doesn't you can then use an EZ out.

 

If the bolt bottomed in the hole, it probably won't spin out with just the drill bit. EZ out may work, if not, then welding a nut to it may be his only option. McMaster Carr sells left-handed drill bits.

 

hate to ask but how much torque did you apply to a grade 8 bolt to make it snap? And are you sure they gave you 4 grade 8 bolts? First time I stuck a motor on a stand I didnt know a grade bolt from a nail. Guy at the hardware store gave me 4 bolts with no marking on the heads. Luckily I still had the motor hooked to the hoist as I lowered it and all four bolts snapped! jim

 

They were all in individual bags marked 3/8-16 3-1/2" grade 8. Chances are i Put way to much torqe on the bolt... Obviously. Tried drilling.. No sucess. Left bit started getting close to the block threds. Ive given up tonight. Very disapointed in my work.

 

What exactly is ez out?

 

An EZ out is a hardened steel shank with a tapered left-hand spiral milled into it. They look kinda like a tap with a square tip at one end. The spiral has a sharp edge that bites into the broken bolt that's been drilled out. A wrench or tap handle can be used on the square tip to turn the EZ out counter clockwise to back the bolt out of the hole. They're usually sold in sets with 5 or 6 different sizes for various size bolts. Here's a link to a set at Sears:

http://www.sears.com/tools-hand-too...d=ez+out+extractor+set&autoRedirect=true&viewItems=50&redirectType=CAT_REC_PRED

 

heat the bolt with a torch, get it nice and hot. use some wax (parafin) and apply it to the hot bolt and will suck the wax up into the threads. Let it cool then take a center punch and start tapping around the bolt perimeter until it comes out. Tap in the loosening direction of course. It will work just make certain your punch is tapping the bolt out as you go. A sharp point ids good.

 

Just because a bolt has grade 8 markings does not mean it meets grade8 specs. We find counterfeit bolts quite often.

Personally, I would not trust a bolt bought at a "big box store" to be up to specs. I would have went to a auto parts that sells Dorman if you don't have access to a real bolt supplier.

Keep in mind, "grade 8" is a specification, not a specific alloy.

 

Just because a bolt has grade 8 markings does not mean it meets grade8 specs. We find counterfeit bolts quite often.

Personally, I would not trust a bolt bought at a "big box store" to be up to specs. I would have went to a auto parts that sells Dorman if you don't have access to a real bolt supplier.

Keep in mind, "grade 8" is a specification, not a specific alloy.

fwiw Dorman is China now

 

And then there's "Grade 8.2". 8.2 is way inferior to a "true" Grade 8 bolt.

 

And then there's "Grade 8.2". 8.2 is way inferior to a "true" Grade 8 bolt.

I'm thinking 8.2 refers to metric bolts.

 

Easy outs are what keep EDM men in business.

 

Posted by novaderrick:

close, but not quite... and EZ out is a device made out of hardened steel that starts to spin out broken bolts, then breaks off just as you think you are about to make progress... then you have a chunk of steel that is harder than any drill bit that is stuck in the block wedged inside the broken bolt...

Awesome post!! How true it is, as any EZ Out user can testify from experience. Still, they are a lifesaver.

 

If its broken into a hole where the surrounding metal doesn't have to be machined....such as where a transmission would mount to the back of the block...

Get a thin cut off wheel and cut a line in the stud...this will also cut small lines in the surrounding metal, and use a big mofo screwdriver or get a flat tip socket and torque that puppy out. Do it all the time...

It CAN be done on a machined surface if your careful etc...as long as your line doesn't get too long and exceeds the gasket or other machined part...

 

This requires a little patience and time, but it has worked for me . Take a small drill bit, maybe 1/16" or 1/8". Drill into the broke bolt. Then progressively use the next size larger bit. Slow steady drilling will get most of the bolt out, then chase remaining metal out with WD 40 or PB Blaster. A slightly smaller bolt may help in removing last bits of metal. All your really doing is making the bolt weaker by removing all or most of its guts. Slow, but keep at it. It works. Give it a try...............:thumbsup:

 

looks like someone watched Powerblock yesterday... the guy on Musclecar! did just that, right down to the WD40 part..

 

I will be trying the ez out option. Then i will be selling the engine for a new big m dart. The post on here have been great and i appreciate all of your help!

 

IF you want real advice to getting the broken bolt out, take five minutes out of your day to get a nice clkoseup pic of the offendor.
There are degrees of a broken bolt.

 

Bolt head markings:
http://www.engineeringtoolbox.com/steel-bolts-sae-grades-d_1426.html


Some info on grade 8 and grade 8.2 On ebay of all places.

http://www.ebay.com/gds/INFERIOR-Grade-8-2-bolts/10000000001355465/g.html

 

Here yall go.. See the damage.

 

Just a quick chime in here but I cant belive you didnt strip the threads in block before breaking that bolt.

 

John, you got me itching to grab a small punch and a hammer just to see if I could walk it out.

 

Exactly my thoughts. Have done it before with good results. Have even used the sharp outer edge of a small chisel to try to spin that thing out.

 

Well either it was a cheap defect bolt or apparently I'm related to the hulk. And i dont turn green when mad so im thinking its a defect

 

You can see the defect where the threads were rolled. It does not look like you Super Gorillaed it so you stand a good chance of a few well placed taps of a hammer and punch will back it out enough to get some Vice-Grips on it,

 

Great stuff here.

I love taking out broken bolts, especially when someone else broke them....

All the tips are here for success.

Ryan

 

I love taking out broken bolts, especially when someone else broke them....

Oh, yeah. As long as "someone else" isn't on my payroll.






Anyone know a good chart of manufacturer's marks for bolt heads? First Guess: JH is Chinese.

 

maybe i'm wrong, but isn't that bolt hole drilled all the way thru the front side of the starter mounting boss on some blocks? if so, get at it from the front with a regular 1/4" or so drill bit and see if you can't get it to bite in and screw the bolt back out...

 

I have bought grade 8 bolts at a bolt supplier that did not meet specifications.
I had several break. I sent the broken bolts along with some from the same batch that had not been used to a lab for testing and they were junk.

Ended up suing the supplier because they would not stand behind them. Won the case.

Chinese junk everyplace. :angry::angry:

 

The bolt does not go all the way tgrough. It has a stopping point