[bobbo]

Think that pretty much says it all. Was removing my forks to fit the Ricor Intiminators and the top clam bolt on the left hand side has sheared. What the bloody hell do I do now?

All comments gratefully received!
Cheers
bob

 

[geolpilot]

Drill it and take it out with an easy out. If you aren't comfortable doing that, take it to a machine shop.

 

[bobbo]

Broke my easyout! Guess I'll have to drill it and tap it. Bummer.

 

[marc hanna]

Yup, drill it out. Buy a new bolt, get a drill bit with a diameter close to but no larger than the root diameter of the thread of that bolt and drill out the sheared bolt, being very careful to stay parallel to the axis of the sheared bolt. When you're to full depth the remaining thread of the bolt will just come out freely. Use a center punch to dimple the sheared-off bolt before you start drilling; this will prevent the drill point from wandering when you start drilling.

There are what's called "pilot point" drill bits out there (in Canada Canadian Tire sells them) that will aid in getting your hole nicely centered when you start, if the sheared surface is not flat or is angled.

 

[sweatmachine]

take it to a machine shop

 

[marc hanna]

Also, so you don't drill too deep, using the new bolt as a gauge, mark the drill bit with a piece of masking tape (or permanent marker, or white-out, or anything highly visible when the bit is spinning).

 

[fat frank]

Be Carefull

Being a machinist, I'ld say it's next to impossible to accurately drill the bolt at the root of thread diam. without hitting the threads. Ok to go in smaller and use an easy out. If you are trying to open the hole up to the root of thread, needs to be done with an end mill. If you already have a hole drilled for the easy out, the next drill size will follow it. Better listen to Sweat. Good luck

 

[mikeinva]

Being a machinist, I'ld say it's next to impossible to accurately drill the bolt at the root of thread diam. without hitting the threads. Ok to go in smaller and use an easy out. If you are trying to open the hole up to the root of thread, needs to be done with an end mill. If you already have a hole drilled for the easy out, the next drill size will follow it. Better listen to Sweat. Good luck

+1 ON THAT pull it apart take it to someome will a milling machine ,if the easyout is still in there you wont be able to drill it with regular drill bit there to hard.carbide end mill is the way to go now.

 

[marc hanna]

I've done this several times on machine spindles (big expensive CNC's); as long as you have the work piece horizontal or vertical and your hole starts off central, it's not a problem. If you're off-center a bit, you will only nick the threads on one side, which will not have an adverse affect unless you wipe them out completely. Given that screw threads only engage from 50 - 60% and if your bit is 1/64" smaller than the root diameter of the screw thread, you would have to be way off in order to screw this up.

But if you're not comfortable doing this type of work, then I would definitely recommend a machine shop.

 

[marc hanna]

+1 ON THAT pull it apart take it to someome will a milling machine ,if the easyout is still in there you wont be able to drill it with regular drill bit there to hard.carbide end mill is the way to go now.

If the easy out is still in there, you'll probably need to die-sink it out. You won't get through HSS (High Speed Steel) with a carbide drill.

 

[marc hanna]

Fat frank,

It just occurred to me that I may have completely devalued your opinion with my post. I apologize, you certainly make a good point and your experience is certainly relevant.

My point is that, if someone is intent on a DIY, this can certainly be done in the manner I have described, as I have done it many times and never with a screw-up (pardon the pun).

 

[propforward]

It can be done by hand, but it is tricky - on a big bolt you can sometimes drill into it with a small drill, then keep upping the size of the drill until you get the thing to basically collapse, or get so weak you can kind of pick it out. With luck you never actually need to go to a drill that is so big that you will dril into the threads, that way being off center isn't such a big deal. Sometimes you can tack weld another bolt onto it...all depends what is protruding.

You have to judge your own skill set and confidence against the job - taking the clamp to a machine shop is a very sensible suggestion. It shouldn't even cost that much to do.

 

[sweatmachine]

You have to judge your own skill set and confidence against the job - taking the clamp to a machine shop is a very sensible suggestion. It shouldn't even cost that much to do.

I'd bet it would cost whatever the shop minimum is, at least it works like that around here. I've had the machine shiop near my place remove a few bolts for me and it's usually $15-25 depending on the guy's mood I guess.

Another method would be to get some left handed drill bits, a small and large, start drilling into it and it might back out easily. I've done this method. Some good penetrating oil helps too, PB Blaster is good.

 

[propforward]

You're probably right. I know a few machinists that can help me out in times of trouble like this and they don't worry about the shop charge minimum, but I work with them professionally and send them real work, so I'm lucky that way.

I like the left handed drill idea, I've never done it that way but I bet that could work out very well.

 

[sweatmachine]

I like the left handed drill idea, I've never done it that way but I bet that could work out very well.

it can be tough to find left handed bits. I had to search high and low around Austin and finally found a specialty tool shop that carried them. They weren't cheap either, like $4-5 each for 2 small ones.

 

[propforward]

Ouch!

Still, not bad to have in the toolkit for future projects.

 

[marc hanna]

the left-hand drills are ideal and they're probably a stock item in any industrial tool supply outlet. Or else try KBCtools.com. Quite often the bit with snag part way down the hole, and with the combination of heat generate from drilling with the bolt's ability to collapse in on itself, a seized bolt will just spin out.

In the case where a bolt is just sheared off at the head, there's usually no torque on the threads anymore, unless they're mashed from being over-torqued or galvarnically welded together due to dissimilar material properties, so they'll usually come out a lot easier than a seized bolt.

 

[propforward]

I bet mcmaster carr has them.

www.mcmastercarr.com

Yes they do:

http://www.mcmaster.com/#left-hand-drill-bits/=288sji

 

[marc hanna]

^^Those prices are quite reasonable, plus they're cobalt so you might actually be able to you them a second time

 

[mikeinva]

If the easy out is still in there, you'll probably need to die-sink it out. You won't get through HSS (High Speed Steel) with a carbide drill.

dont think i said a drill i said a end mill .you can ether use a hollow mill and cut around it,till you get the esay out out or take a small end mill and go around it .There are some things you can do with a mill you cant do with a drill.