The Dutchman
Well-known member
Every mechanic, no matter what stripe, has come across it: you're doing great, using, say, your 1/2" impact during dis-assembly & suddenly, the bolt you're removing stiffens up, becomes harder to turn. Before your mind can react & let off on the gun, you've snapped that sucker.
If the remaining bolt section is protruding from the female threaded component, you can use a stud remover, but if it's flush with or recessed in the female threads, you gotta go with one of the innumerable "easy out" solutions.
On p. 418 & 417 of what I think is the current Matco Catalog is their 4 step "Bust-n-Out" system. Here's the Step 1 kit:
http://www.matcotools.com/catalog/product/ZBEC5/5-PIECE-BUST-N-OUT-SET-STEP-1/
They are basically carbide end mills, but with no flutes, spiral or otherwise. The cutting plane is perpendicular to the shank. Using an angle head die grinder, you use them to make flat the necessarily rough & contoured broken bolt surface, a big advantage, IMO, in making it easier to then start a drill or "holemaker" in the exact center of the bolt.
Step 2:
http://www.matcotools.com/catalog/product/ZBCD5/5-PIECE-BUST-N--OUT-SET-STEP-2/
These bits are just like the Step 1 bits except cutting edge not
perpendicular to shank; they look to have around 160 degree "drill points". Again you use a right angle die grinder. No flutes, but no problem; they only bore in far enough to create a conical concave shape on the broken bolt's exposed surface. (The "Step 3 carbide drill bits have the same drill point angle as the corresponding Step 2 bits, creating a perfect fit.) The diameter of the Step 1 & 2 bits is perfectly computed to be a hair less than the root diameter of the corresponding bolt size, so you won't destroy the female threads in question.
Here's Step 3:
http://www.matcotools.com/catalog/product/ZBDR4/4-PIECE-SOLID-CARBIDE-DRILL-BITS/
These bits are sized to be used with the following extractor set:
http://www.matcotools.com/catalog/product/SE25/5-PIECE-SCREW-EXTRACTOR-SET/
Personally, I think this system's price would only be justifiable if you extract a lot of bolts broken off well within the female threaded component. That way, the Step 1 & Step 2 bits would automatically center themselves. I suppose the carbide bits would speed things up, since they tear through most bolt steels like butter, but 2 bills for 4 bits--Jeez!
I've already bought the Step 1 set. Can't see how it wouldn't facilitate getting the hole drilled in the center of the broken bolt shank.
I apologize for the length of this post, but I wanted to make sure people understand how these sets work with each other!
What do people think of this system?
If the remaining bolt section is protruding from the female threaded component, you can use a stud remover, but if it's flush with or recessed in the female threads, you gotta go with one of the innumerable "easy out" solutions.
On p. 418 & 417 of what I think is the current Matco Catalog is their 4 step "Bust-n-Out" system. Here's the Step 1 kit:
http://www.matcotools.com/catalog/product/ZBEC5/5-PIECE-BUST-N-OUT-SET-STEP-1/
They are basically carbide end mills, but with no flutes, spiral or otherwise. The cutting plane is perpendicular to the shank. Using an angle head die grinder, you use them to make flat the necessarily rough & contoured broken bolt surface, a big advantage, IMO, in making it easier to then start a drill or "holemaker" in the exact center of the bolt.
Step 2:
http://www.matcotools.com/catalog/product/ZBCD5/5-PIECE-BUST-N--OUT-SET-STEP-2/
These bits are just like the Step 1 bits except cutting edge not
perpendicular to shank; they look to have around 160 degree "drill points". Again you use a right angle die grinder. No flutes, but no problem; they only bore in far enough to create a conical concave shape on the broken bolt's exposed surface. (The "Step 3 carbide drill bits have the same drill point angle as the corresponding Step 2 bits, creating a perfect fit.) The diameter of the Step 1 & 2 bits is perfectly computed to be a hair less than the root diameter of the corresponding bolt size, so you won't destroy the female threads in question.
Here's Step 3:
http://www.matcotools.com/catalog/product/ZBDR4/4-PIECE-SOLID-CARBIDE-DRILL-BITS/
These bits are sized to be used with the following extractor set:
http://www.matcotools.com/catalog/product/SE25/5-PIECE-SCREW-EXTRACTOR-SET/
Personally, I think this system's price would only be justifiable if you extract a lot of bolts broken off well within the female threaded component. That way, the Step 1 & Step 2 bits would automatically center themselves. I suppose the carbide bits would speed things up, since they tear through most bolt steels like butter, but 2 bills for 4 bits--Jeez!
I've already bought the Step 1 set. Can't see how it wouldn't facilitate getting the hole drilled in the center of the broken bolt shank.
I apologize for the length of this post, but I wanted to make sure people understand how these sets work with each other!
What do people think of this system?