Sheared screws and bolts removal

[GaRoadsterRookie]

As I keep digging deeper and deeper into the restoration of my Roadster, I continue to encounter screws and bolts that shear off during removal. It could just be the general state of my rusty car but I am trying to keep moving forward. I would love some step by step instructions on how to remove the remaining screw or bolt. I can't seem to find good material on the general Internet. So please share your successful methods with me, recommended tools and all.

To be upfront, I have no welding tools or welding skills. I have tried applying heat to some before they sheared. Some of my current problem points are 1) front air dam bolts that attach it to the frame - both sheared 2) 3 out of 4 screws that attached the center console to transmission tunnel.

Share your wisdom and recommended tools, drill bits, wrenches, etc. Thanks.

[jrusso07]

Two options I have used, drill out the broken bolt with a bit smaller than or close to the broken bolt diameter and be prepared to re-tap the threads. Sometimes, if you hit it right, the rusted in bolt will break free in the process. Second, Sears and other tool companies make a couple of decent extractor kits. One requires drilling, the other graps the outer diameter of the broken bolt assuming you have something to grab hold of.

Here's the first example http://www.sears.com/craftsman-7-pc-pow ... 953153000P" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Here's the latter http://www.sears.com/shc/s/p_10153_1260 ... 2506194811" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

[sfdaugherty]

I have a couple of sets of left-handed drill bits. I start out small and use a center punch so that the bit doesn't wander. Take your time and let the drill do the work or you'll snap off the bit. Keep using larger bits until you either get the remainder of the snapped off screw or bolt wrapped around your bit or the hole is large enough to tap.

Shannon

[greydog]

Usually when I break a bolt it doesn't shear cleanly and leaves a kind of ragged surface so I'll use my Dremel with a small grinding stone and smooth or flatten out the area in the center of the bolt or screw.
I soak the rusted stub in penetrating oil (I like PB Blaster). Then I have a spring loaded center punch that I can place at the center of the broken bolt to give a start point. After that, I take my trusty ball peen and a larger center punch and enlarge the dimple so my drill won't walk on the bolt stub.
Once I have a good center, I drill a hole with a small (3/32 usually) drill, then step drills larger until I"m near the bolt diameter. Usually by that time the stub has come loose.

Dan

[GaRoadsterRookie]

I am not familiar with a spring loaded center punch. What brand is it and where can I get one?

Thanks for all the great tips! Keep them coming.

[Garm]

this. $9.
http://www.harborfreight.com/12-piece-s ... 40349.html" onclick="window.open(this.href);return false;

[pebbles]

Usually when I break a bolt it doesn't shear cleanly and leaves a kind of ragged surface so I'll use my Dremel with a small grinding stone and smooth or flatten out the area in the center of the bolt or screw.
I soak the rusted stub in penetrating oil (I like PB Blaster). Then I have a spring loaded center punch that I can place at the center of the broken bolt to give a start point. After that, I take my trusty ball peen and a larger center punch and enlarge the dimple so my drill won't walk on the bolt stub.
Once I have a good center, I drill a hole with a small (3/32 usually) drill, then step drills larger until I"m near the bolt diameter. Usually by that time the stub has come loose.

Dan

+1, in addition the heat from the drilling process can break the stub loose. Running the broken stub "in" has been easier for me than trying to bring it out, (sharp bit slow rpm), the drilling process may do that on its own.

[sfdaugherty]

I am not familiar with a spring loaded center punch. What brand is it and where can I get one?

Harbor Freight has a center punch with brass handle for $2.99. That's the one I use.

Can't beat the price.

Shannnon

[notoptoy]

Some tips before hand -
Soak everything you want to remove, or think you may ever want to remove in your choice of penetrant. Wait as long as possible before attempting to remove the item, repeating penetrant applications as practical. Then after 36 months and 45 applications of rust penetrant (your timing may vary), first try to TIGHTEN the fitting - just a touch - then try to loosen it. If this frees it up nicely, great - hit it with penetrant again, and ease it the rest of the way out. If it moves just a bit but is still very tough, tighten again, and then slowly work the fitting in and out, gradually more out each time - while hitting with penetrant along the way.

Then, when that fails (being realistic here) use the above extraction methods!
Good luck

[dbrick]

My $.02


If you can, practice on some junk parts.
If the bolt goes through, try drilling with a sharp regular bit. Start with a 1/8", then move up closer to the size, slow drill, like a cordless on low speed, no clutch no oil. If the bit catches, it turns the screw right through the hole. If not, use oil and drill through.

Dad was a tool and die maker, this was required learning by age 14. If anything is sticking out, file or grind 2 flats, then heat and a vise grip. If you use oil, degrease with brake clean before trying vise grips so the tool doesn't slip off as easilly If that fails, grind it to a flat and, center punch as best you can, start small and get it centered. The bigger bit will follow the pilot hole. Drill slowly, use oil.

With practice, If you start the hole off center, you can recenter your hole by drilling at 45 degrees toward center and slowly standing the drill back up to centered. Hard to explain, but if you need to do it, it will make sense.

I used to drill out LOTS of pins on the distributors, so I'm learned which bits work. Believe it or not, the Harbor Freight TiN (Titanium Nitride) bits are half decent,not too brittle, 10 pack is a few dollars, toss it when it gets dull. Dewalt TiN are good too. For larger holes, if you can get shorter bits, usually called "Screw Machine" bits vs. Jobber bits, they are a little softer and being shorter tend not to break.

Screw extractors are the last ditch, you need to use the right size and drill the correct hole on center. Again, clean off any oil for a better bite, then tap it in straight with a hammer turn carefully, with a 2 handle tap holder if possible. You can also use 2 wrenches 180 degrees apart, whatever lets you turn it and keep it straight. They will snap if you twist them off center, and you can't drill them. I've had good luck with the Snap-on 4 sided square extractors instead of the spiral, especially in softer bolts and pipe fittings.

Worst case, drill it all the way out, use a helicoil kit.

References
http://www.madelectrical.com/workshop/b ... olts.shtml He has GREAT electrical knowledge too.
http://www.irwin.com/tools/browse/screw-bolt-extractors
http://www.secondchancegarage.com/public/671.cfm
http://www.google.com/url?sa=t&rct=j&q= ... jQ&cad=rja