# Drill Hardened Steel



## Oneacer (Jan 3, 2011)

What type of drill has anyone used to drill through a snapped off, hardened steel easy-out?

My regular drill bits won't touch it.

Happened on an exhaust bolt on small engine ... not the end of the world really, as I can use the pipe thread, which is excellent, but would like to attempt to remedy the bolt hole.


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## deezlfan (Nov 8, 2017)

Observing with interest. Wager nothing you can use in a hand held drill.


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## dman2 (Sep 22, 2019)

Oneacer said:


> What type of drill has anyone used to drill through a snapped off, hardened steel easy-out?
> 
> My regular drill bits won't touch it.
> 
> Happened on an exhaust bolt on small engine ... not the end of the world really, as I can use the pipe thread, which is excellent, but would like to attempt to remedy the bolt hole.


I just drilled a cotter pin hole through my friction disc hex axle. It took me a couple of hours to drill it. Broke multiple drills bit. Titanium drill bits, or not, they don't last very long, so buy them in quantity.


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## scrappy (Dec 7, 2014)

I just watched a utube vid, where they drilled and tapped hardened transmission shaft. Used a masonry drill bit, had to sharpen with a grinding wheel, but it did finally drill into the softer part of the shaft.


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## Beanhead (Oct 17, 2021)

This is not cheap but my work for you.


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## Cstanis (Oct 19, 2021)

Cobalt drill bits work sometimes. Very tough going no matter what you use


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## jherbicide (Oct 14, 2021)

Cstanis said:


> Cobalt drill bits work sometimes. Very tough going no matter what you use


Yep, and very hard to do by hand. They’re brittle so gotta hold very straight.


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## vmax29 (Oct 19, 2017)

Tungsten carbide bit. A little pricey but it should go through hardened steel. Use a good cutting oil when drilling.


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## crazzywolfie (Jun 2, 2014)

if you got a torch that uses oxygen you could try heating it up till it is glowing red then let it cool. should hopefully help soften the metal to make it easier to drill with normal bits.


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## distrbd (Dec 8, 2021)

I sure would try a carbide bit before I start trying to anneal with a torch.
Drilling is best done on a mill .


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## Oneacer (Jan 3, 2011)

I would love to try that Rescue Bit, but not at 50.00 for a 1/8-inch bit ...


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## Cstanis (Oct 19, 2021)

Oneacer said:


> I would love to try that Rescue Bit, but not at 50.00 for a 1/8-inch bit ...


Called a friend of mine who is a tool maker his first reply was good luck. He said if you are trying a hand drill it will be tough a drill press would be better. Tungsten carbide will work but the key is patience. There is a chance drilling could work harden it even more. Just his thoughts


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## distrbd (Dec 8, 2021)

I'd love to have that 1/8" rescue bit for my flex shaft grinder but by the time it's delivered to Canada it'll be like $100 , not many jobs in my shop can justify a $100 bit.


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## Andrewnyc (Jan 10, 2022)

I think going through will be next to impossible, but if you try to carefully drill along side it you may be able to loosen it. In other words use small bits in the steel next to its grooves.
another way might be trying to weld something to it for leverage, but without a pic I don’t know if that’s an option


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## Oneacer (Jan 3, 2011)

Yeah, already tried the side method, a no go .... I originally drilled the broken bolt with two size bits ... I should have kept drilling, then clean out with a tap, but thought I would try the little easy out, and unfortunately it snapped .. no real biggie, as I will be installing a pipe fit exhaust ... I will know for next time to keep up-step drilling and re-tap. ... Think I will pick up one each of these ...


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## foggysail (Feb 21, 2015)

If you have a welder, welding a nut onto the stud might do it.


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## Toon (May 11, 2021)

1. If you can get to the back side of the hole, hit the broken easy out with a punch. If you can't get to the back side use a sharpened drill blank and hit it from side to side. If it loosens you might get lucky and get it out.
2. A sharpened carbide tipped masonry bit is your second choice.
3. A Stellite drill will also work but they are not cheap and it should be done on a mill or at the very least a drill press or the drill will wander to the side.
All three of these methods have worked for me in the past and all three of these methods have also failed, so good luck.


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## orangputeh (Nov 24, 2016)

go another way if you have an option. pipe thread as mentioned. this is near impossible unless money is no object.

BTW I always use good drill oil to save my expensive HSS bits. ( learned hard way of course )

good luck.


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## snow blows (Jan 9, 2016)

Oneacer said:


> What type of drill has anyone used to drill through a snapped off, hardened steel easy-out?
> 
> My regular drill bits won't touch it.
> 
> Happened on an exhaust bolt on small engine ... not the end of the world really, as I can use the pipe thread, which is excellent, but would like to attempt to remedy the bolt hole.



Harbor Freight had easy-outs on sale? Only thing that would go through a Stihl chainsaw bar was a cobalt bit. Ruined probably 15 bits to figure that out.


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## JJG723 (Mar 7, 2015)

A carbide bit is a must. But if you're drilling by hand, drill walk is going to be a major problem.


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## dman2 (Sep 22, 2019)

Oneacer said:


> I would love to try that Rescue Bit, but not at 50.00 for a 1/8-inch bit ...


Are you trying to extract a broken bolt? If you are, then buy the rescue bit set at harbor freight. I remember it wasn't that expensive. I used it once to extract a broken bolt and it worked very well. It worked much better than welding a nut to it.


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## dman2 (Sep 22, 2019)

*Actually, they called it "Screw Extractor" instead*


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## dman2 (Sep 22, 2019)

Drill a bigger hole and then tap and die also work. I just did that recently but soft metal.


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## Oneacer (Jan 3, 2011)

Unfortunatly, a hardened screw extractor is what snapped .... Impossible to drill into hardened steel.


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## dman2 (Sep 22, 2019)

If you can drill it it a tiny bit and then use a self-tapping screw, it would probably remove the screw extractor for you.


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## Oneacer (Jan 3, 2011)

The in lies the problem ....  .... Can't drill hardened steel.


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## dman2 (Sep 22, 2019)

Try carbide burr bits


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## dman2 (Sep 22, 2019)

Where you cant drill, you grind. But those bits won't go in deep. I used those bits on rotary tools all the time.

I usually hammer a nail in first. That will make a small dent where I want to drill it. Those grinding bits also does that for you. Hand drilling take a long time. If you can't keep straight, those bits shatter to pieces. They are brittle as someone has mentioned.


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## Yanmar Ronin (Jan 31, 2015)

Cobalt or titanium bit _might_ also work... a little cheaper to try anyhow. 🤞

And ya you really want to jig it up on a drill press.


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## dman2 (Sep 22, 2019)

Sometime, I used all my body weight, otherwise it won't drill in. Good to have a drill press.


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## deezlfan (Nov 8, 2017)

Titanium bits are only coated with titanium nitride, mainly for higher speed use. They aren't really much better than black oxide HSS in most hand held situations. Cobalt is superior for drilling harder metals and are usually used in a drill press or mill as they aren't tolerant of side forces.


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## tlc1976 (Dec 24, 2021)

My uncle was a gunsmith and sometimes would break a tap in rare/expensive guns. He said if you hit it with a hardened punch enough times the tap will crystallize. This was 30 years ago.

Of course the difference with a tap is the flutes give space for it to crumble. A screw extractor not so much, it’s pretty much solid. Never tried it though.


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## Oneacer (Jan 3, 2011)

All this being discussed is interesting, but being an aluminum head, moving over to its internal exhaust pipe thread is really a no brainer in my opinion .... That thread is perfect, I have the piping, and new muffler under 10.00.



If I ever come across one of those expensive bits, I'll probably try it .... Lol, not anticipating that.....


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## Yanmar Ronin (Jan 31, 2015)

No argument... but it would bug me to death/OCD leaving it in there. 🙃


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## Oneacer (Jan 3, 2011)

Yeah, got some OCD going on here as well, but they have the option for either type, so not to concerned, when the heater box is back on, you'll never notice ..... 

I actually like the pipe style round/oblong mufflers.


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## crazzywolfie (Jun 2, 2014)

do you have a stick welder? with a small welding rod you could always try welding a rod to the extractor and home to break the extractor free. maybe worse case scenario you will soften it.


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## ST1300 (Feb 17, 2017)

Not having a picture, it's hard to say exactly what to do. Are you using a straight fluted style with a nut that slides over it, or a square taper or twisted taper. And how deep in the hole is the bolt and/or extractor broken? Can you grind a taper on one edge of a nut and set it so you can "plug weld" in the center to the extractor or original bolt? If there is no part sticking out where you can weld a nut or something to it, so you can unscrew the whole mess, your best bet is an oxy-acetylene torch with a "0" or "00" tip so you can heat the extractor (red if possible) quickly without melting the base aluminum around it. (aluminum melts at 1100 degrees, steel gets red hot at around 3500 degrees) It may take two or three times of heating, each time let it cool as --Slow As Possible-- and it will soften the steel so it can eventually be drilled. Drill speed should be no more than 300 to 400 rpm and use a cutting/cooling oil or spray, constantly (not just in bursts). Best drilled in a press/mill, but can be carefully done manually.
Eventually if you end up drilling out the steel and the aluminum threads, the best type of thread restore then would be the type with three or four "keys" to lock it to the aluminum, "Keensert brand"? but they need a lot of base material around them to install. A "Heli-coil" might work but it will probably "unscrew" itself the next time you remove the bolt. 
Good luck, you really are at that proverbial point, "between a rock and a hard place".


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## Yanmar Ronin (Jan 31, 2015)

If you were gonna go to all that trouble it'd be easier to just drill it all out to the next size up and tap some new threads, space permitting.

For a muffler I agree abandoning the wreckage and going to the pipe-threaded setup will be easy safe and fun.


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## vmax29 (Oct 19, 2017)

Thinking about this, if any of the easy out is sticking out of the boss you could slot it with a grinder. Try a large screwdriver or an impact driver. I have had luck breaking loose snapped bolts that way.


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## Oneacer (Jan 3, 2011)

It snapped flush with the head surface ... Funny you mention that though, as I did even try that already with my Dremel cut off, to no avail.


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## deezlfan (Nov 8, 2017)

> No argument... but it would bug me to death/OCD leaving it in there. 🙃


Break a bolt off in the other hole so it matches. Badabing badaboom.


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## Andrewnyc (Jan 10, 2022)

Snapped flush then make a little space for access and use a punch and hit in the out direction and it will come out- I don’t really know -that but I think it will. but if it moves, then a little back and forth will be necessary 
I’ve never had luck with this either always drill sequentially bigger until you can remove it, and by then it practically falls out or in which could be bad.


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## tabora (Mar 1, 2017)

Oneacer said:


> Can't drill hardened steel.


Any metal can be drilled...


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## Cstanis (Oct 19, 2021)

Do you have any small machine shops around you, if so call and ask them if they have an EDM (electrical discharge machine) they use them to blow out broken taps, drills etc.


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## Oneacer (Jan 3, 2011)

In aluminum head, snapped flush, which is on engine, which is on blower .... no biggie, .... I am using the alternate method with the internal thread ..... I am not taking this all apart just for a small bolt when I don't even need it .... I figured there was no easy way.


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## Beanhead (Oct 17, 2021)

Oneacer "I figured there was no easy way" at least you can work around it and save the motor


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## crazzywolfie (Jun 2, 2014)

Oneacer said:


> snapped flush,


weld a washer to it then weld a nut to the washer to use a slide hammer on


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## Andrewnyc (Jan 10, 2022)

Tie a fishing line to it run it through one of your top incisors, tie it to a door handle, get the line taught and slam the door. I saw it on a show once when I was younger. May have been a diy show


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## JJG723 (Mar 7, 2015)

Cstanis said:


> Do you have any small machine shops around you, if so call and ask them if they have an EDM (electrical discharge machine) they use them to blow out broken taps, drills etc.


Funny you mentioned EDM. Being a machinist myself who has done EDM work this is the first thing I thought of. I didn't bring it up because I knew Oneacer was looking for a simple, easy way out. Not to disassemble the head to bring to a machine shop lol. But yes you are right. That would be easy peasy.


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## Oneacer (Jan 3, 2011)

6.99 for a new muffler at Tractor Supply, .... won't even need to modify heater box, will fit right where old was. ..


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## Cstanis (Oct 19, 2021)

Oneacer said:


> 6.99 for a new muffler at Tractor Supply, .... won't even need to modify heater box, will fit right where old was. ..
> 
> View attachment 187082


Run open pipes the noise keeps you awake


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## Oneacer (Jan 3, 2011)

Awake and deaf ...


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## groomerz (Feb 7, 2015)

Go with your plan b

Put the cheap muffler on
Run engine let cool. Run engine
Vibration and heat cycle might 
free it free the broken extractor 

Eventually

My 2 cents


Sent from my iPhone using Tapatalk


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## Oneacer (Jan 3, 2011)

That bolt has the extractor broke flush inside it, and both flush with the aluminum block ... that sucker is never going to be coming out ....  ... at least not in my lifetime ....


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## orangputeh (Nov 24, 2016)

Oneacer said:


> All this being discussed is interesting, but being an aluminum head, moving over to its internal exhaust pipe thread is really a no brainer in my opinion .... That thread is perfect, I have the piping, and new muffler under 10.00.
> 
> 
> 
> If I ever come across one of those expensive bits, I'll probably try it .... Lol, not anticipating that.....


why did you ask the question?


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## Oneacer (Jan 3, 2011)

To see if there was something new out there that I might be missing ....


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## groomerz (Feb 7, 2015)

You could get 2 mufflers and a tee fitting and some street 90s and a short 1” long threaded piece. Make some cool dual exhaust to quiet it down


Sent from my iPhone using Tapatalk


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## Oneacer (Jan 3, 2011)

Lol .... that would look cool ....


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## Cstanis (Oct 19, 2021)

groomerz said:


> You could get 2 mufflers and a tee fitting and some street 90s and a short 1” long threaded piece. Make some cool dual exhaust to quiet it down
> 
> 
> Sent from my iPhone using Tapatalk


Side winders rat rod that blower


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## tabora (Mar 1, 2017)

Oneacer said:


> Lol .... that would look cool ...


Or turn that elbow straight up and put a stack on it with one of these at the top!


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## Oneacer (Jan 3, 2011)

Hmmmm ... they do have a 1 inch one ...


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## Chils (May 13, 2021)

crazzywolfie said:


> weld a washer to it then weld a nut to the washer to use a slide hammer on


This is the correct answer except all you need to do is unscrew the bolt/extractor after welding. No slide hammer for me. The heat from welding also expands the threaded hole and allows the broken bolt to turn out easier.
I did this to a bottomed out and broken off bolt in my aluminum GT transaxle case. Spun out rather easily after welding a nut on it.


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## Python33 (Oct 18, 2021)

Oneacer said:


> What type of drill has anyone used to drill through a snapped off, hardened steel easy-out?
> 
> My regular drill bits won't touch it.
> 
> Happened on an exhaust bolt on small engine ... not the end of the world really, as I can use the pipe thread, which is excellent, but would like to attempt to remedy the bolt hole.


Carbide is an option to go through hard steel. McMaster-Carr


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## BNSFguy (Nov 2, 2019)

Oneacer said:


> What type of drill has anyone used to drill through a snapped off, hardened steel easy-out?
> 
> My regular drill bits won't touch it.
> 
> Happened on an exhaust bolt on small engine ... not the end of the world really, as I can use the pipe thread, which is excellent, but would like to attempt to remedy the bolt hole.



I've been a machinist my whole life. I would NOT use "carbide" if you're hand drilling. It's extremely hard and brittle. You'll likely immediately chip the carbide drill and waste your money. If you happen to get it started, you'll likely break it off in the hole and than you've got even more problems. What I would use is a HSS end mill to mill out the broken tool. HSS is way more forgiving than carbide, albeit its nowhere near as hard so you may need a couple of end mills. I've had to do this many times using a Milwaukee cordless drill and always have a success.


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## dr bob (Dec 12, 2015)

You can find diamond bits for a dremel or die grinder. Slow going. Buy a box of the bits, and be careful not to let them overheat. Submerged or at least flooded with coolant is safest. If it were a tap or other hardened piece, those can be carefully chipped out if there's room for a "cape chisel". Easy-outs are tougher and won't chip apart.

Critical stuff, especially if something is stuck in aluminum, you may be looking for a place with a good EDM. It essentially "un-welds" and draws the target material with a small submerged arc. Contact your favorite local auto machine shop. Some may have the EDM machine, or they should know who has it nearby.


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## Oneacer (Jan 3, 2011)

Moved on, put in exhaust using the NPT thread ...thanks


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## tlc1976 (Dec 24, 2021)

Good discussion for other times when there isn’t a workaround. Lots of good ideas posted.


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## Oneacer (Jan 3, 2011)

@ tabora,

Although I have it pointing out and down, I think in the spring, when I dismantle and paint it, I think I will use your suggestion, and will point the stack exhaust muffler up and put the rain cap on it like the dozers and other equipment I used to run .... I think that will look so cool ...


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## contender (Jan 18, 2018)

Oneacer said:


> @ tabora,
> 
> Although I have it pointing out and down, I think in the spring, when I dismantle and paint it, I think I will use your suggestion, and will point the stack exhaust muffler up and put the rain cap on it like the dozers and other equipment I used to run .... I think that will look so cool ...
> 
> View attachment 187305


One, you mite consider removing the muffler for sound effects........


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## Oneacer (Jan 3, 2011)

I have the elongated on there now, which I will keep, as it gives a nice quiet throaty sound already ...  I will just face it straight up instead of the out and down position it is in now, and stub a piece out the end to apply the rain cap to ... 

Hehhehe ... I'll be the only one on the block with a stack exhaust ...


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## tabora (Mar 1, 2017)

Oneacer said:


> and stub a piece out the end to apply the rain cap to


You may be able to get one that is the diameter of your muffler can (looks like maybe a little over 2"?) and then you could also add any amount of pipe below the muffler to get a taller stack, if desired.


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## Oneacer (Jan 3, 2011)

I'll be just running a stub piece of NPT pipe into the top end of the muffler to attach the smaller 1" rain cap ... any pipe height if needed will be in the lower NPT section ...


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## Toon (May 11, 2021)

Oneacer said:


> I'll be just running a stub piece of NPT pipe into the top end of the muffler to attach the smaller 1" rain cap ... any pipe height if needed will be in the lower NPT section ...


Be careful that you don’t end up getting a lot of exhaust up around head height. It might be a little too stinky.


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## Oneacer (Jan 3, 2011)

Yeah, I'm not going that high, but will be mindful ......


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## Toolboxhero (Dec 24, 2010)

vmax29 said:


> Tungsten carbide bit. A little pricey but it should go through hardened steel. Use a good cutting oil when drilling.


Agree - use low speed on your drill. 100-200 rpm won't overheat the drill bit and the cutting edge will stay sharp.


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## Cstanis (Oct 19, 2021)

contender said:


> One, you mite consider removing the muffler for sound effects........


Loud pipes save lives


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## tabora (Mar 1, 2017)

crazzywolfie said:


> weld a washer to it then weld a nut to the washer to use a slide hammer on





Chils said:


> all you need to do is unscrew the bolt/extractor after welding.


Just stumbled across this video to demonstrate this technique... (Clink on the "Watch of Facebook" to view.)



__ https://www.facebook.com/video.php?v=447099766916659


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## Chils (May 13, 2021)

tabora said:


> Just stumbled across this video to demonstrate this technique...
> 
> 
> 
> __ https://www.facebook.com/video.php?v=447099766916659


I was a mechanic for 20 years and never knew about this technique until the last couple of years or so. If I had know about it back when I was still wrenching for a living I would never have taken an easy-out out of my toolbox. 

When I was a semi-trailer mechanic aluminum hub oilers would corrode the bolts and they would break off in their iron hubs. They were stuck like nobody's business. Forget an easy-out. We would blow them straight back out of the hub with a torch taking a bath in the sparks. Because the hub was heavy cast-iron the bolt would blow out and the threads didn't get damaged---if you were good at it.

If I had know about the welding technique I would have never pulled the torch out.


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