Least favorite repair task...drilling broken bolts

[Natural Citizen]

...after all the attendant cussing at every step, we finally ended up putting a helicoil in the hole.

Those things are convenient to have around.

 

[Grumblenuts]

Another trick, for say where welding risks further fusing the broken off bolt to the surrounding metal as in the OP case, is to grind a regular screwdriver slot into the bolt using a thin disc. Then, if necessary, weld the slot closed again on the surrounding metal once the bolt is extracted.

 

[Missourian]

Freeze spray isn't just for diagnosing electronics. Expand the outer part with heat. Freeze the inner part. Seldom room to mount a nut splitter in reality. A hammer and chisel works more often. I've extracted a lot of nasty things with just a spring loaded center punch.

Really? I actually used a spring loaded center punch to start my drill bits.

Probably couldn't have gotten to it with anything before it broke...it was in a recessed area, which is why they used the special headed bolt...but I'd like to know how that works for future bolt issues. Just like using a hammer and chisel?

 

[Grumblenuts]

Really? I actually used a spring loaded center punch to start my drill bits.

Probably couldn't have gotten to it with anything before it broke...it was in a recessed area, which is why they used the special headed bolt...but I'd like to know how that works for future bolt issues. Just like using a hammer and chisel?

I've always presumed spring loaded center punches were intended to remove the need for a hammer. To free up a hand, allowing one to perhaps get more creative. Finding one that works reliably is tough but well worth the effort.

Just like using a hammer and center punch, not a chisel though there's some overlap there. The basic idea being to first center punch a spot to grab then angle it a bit to drive whatever (nut, bolt, broken drill bit, ..) in the desired direction (clockwise or counterclockwise).

The disruptive impact or shock wave does all the work, so using a hammer has its advantages, allowing for varying the frequency and amplitude; but the spring loaded version is easier and often fits in spaces where hammering is impossible. Broken off drill bits, for example, often have high spots that can easily be driven to spin them loose. Think broken carbide bit stuck in concrete.

 

[Missourian]

I've always presumed spring loaded center punches were intended to remove the need for a hammer. To free up a hand, allowing one to perhaps get more creative. Finding one that works reliably is tough but well worth the effort.

Just like using a hammer and center punch, not a chisel though there's some overlap there. The basic idea being to first center punch a spot to grab then angle it a bit to drive whatever (nut, bolt, broken drill bit, ..) in the desired direction (clockwise or counterclockwise).

The disruptive impact or shock wave does all the work, so using a hammer has its advantages, allowing for varying the frequency and amplitude; but the spring loaded version is easier and often fits in spaces where hammering is impossible. Broken off drill bits, for example, often have high spots that can easily be driven to spin them loose. Think broken carbide bit stuck in concrete.

I'll have to go looking for a better spring loaded center punch. I don't think mine has the power to move a stuck bolt.

But I will get one.

Thanks.

 

[Grumblenuts]

 

[Concerned American]

I'll have to go looking for a better spring loaded center punch. I don't think mine has the power to move a stuck bolt.

But I will get one.

Thanks.

We used to use manual impact drivers for that.