How to Remove a Stripped or "rounded off" Set screws or cap screws

Difficulty: Moderately Easy

Instructions

Things You'll Need:

Thread taps of various sizes(LEFT HAND TAPS ARE BEST),Concrete drills of various sizes,safty glasses wrenches, bench grinder.

Step 1

grind down wrench and get it to burr or have a curl

All mechanics have had the experience of loosening or tightening a set screw and heard that tell tale "crack" noise that indicates the Allen wrench slipped. With a large enough cap screw its normal no problem. Just get the vise grips on it and turn it out. With a set screw its a different story. Its best to bite the bullet and get the set screw out now. Its not going to get any better over time and it may accumulate rust(not a helpful situation)
The first thing to try is to take an Allen wrench your not too fond of(don't use an heirloom that your grandma handed down)And using the Safety glasses and bench grinder, grind the end of the wrench. Put a little pressure behind the wrench so it tends to burr up on the edges. THIS BURRING IS A GOOD THING,THISIS WHAT WE WANT!!Dont over heat the wrench so it gets soft. ALWAYS QUENCH THE TIP IN WATER !! this will get some of the hardness back that the heat stole. Once ground flat and with the edges burred, Try tapping the Allen wrench into the set screw. It will resist a little.Thats the burr curling over and hopefully wedging the wrench into the set screw. Try turning the wrench and screw out sometimes I get lucky and out it comes ... some times not. If not lets go onto the next trick.
Step 2

here we are removing a set screw from a bearing w/ a tap and wrench

step 2) The next "trick" is to use an appropriate sized tap and tap handle. As I said a left hand threaded tap is best for this but a right hand will work also(yes there is such a thing as a left handed tap, no its not like getting 30 feet of shoreline or a horizontal smoke turner!!)
You may need to grind the tip off a starter tap(tap with a sharp tapering point. You do this so the "meat" of the tap can get down into the set screw.
Once the tap is in the setscrew use a handle to turn it loose.
NOTE: Here's a bonus secret, For 1/4,5/16,3/8,and 1/2 inch taps, If you have to use a tap in close quarters get yourself a "air conditioning wrench" These are ratcheting wrenches used to turn the square plug valves they use in air-conditioning square female holes on these wrenches are perfect for use as a ratcheting handle with these tap sizes!!!
So Ok we did the tap and it still didn't come out. So lets try trick 3
Step 3

Here is a cap screw and a correct sized concrete drill

step 3) or trick 3
In this step we use a concrete drill. ..NO we are not going to drill the set screw out! The set screw if it is not stainless is extremely hard and it would take a special carbide drill to adequately dill into it. The same with a cap screw ... very hard that's why they are so brittle.
So once we find a concrete bit that will fit into the set screw we use a pair of good ,not chewed up vise grips locked on the drill shaft and try to turn out the set screw.
I have also used regular Left hand drill bits to extract set screws and cap screws. Remember that a left hand drill is exactly backwards from a standard right hand drill bit. You need to have the drill motor in "REVERSE" to do the left-handed drill bit. This will cause the drill bit to bite in a leftward direction hopefully turning the screw out. Left hand drill bits are also ...uncommon so hardly anyone has them. Also they are expensive and using them to extract a screw will normally damage the bit. Don't throw it away. Just "re-tip" it and use it over.
Step 4

HERE WE ARE "GLUEING A BOLT AND SOME WASHERSAND NUTS INTO A SET SCREW

TRICK 4)
I have used this trick twice and it worked both times. This trick is not for the sloppy of heart this has to have some precision or you make the situation worse. This is a last ditch trick!!
With this trick you need to use a "Q tip" to clean out the inside of the set screw or cap screw. Use a couple of dry ones to get any oil and then use a couple with alcohol on them.
Once clean you need to find, or grind down, the head of a bolt so it just fits into the set screw pocket. Then you need to put a flat washer or two and a couple of nuts on the bolt as shown in the pix. You then want to put some LOCKTITE STUD AND BEARING MOUNT on the end of the bolt.
NOTE: Only use a drop on the head of the bolt. You don't want too much of this locktite because it may get into the threads. If it does get into the threads then the only way to break it loose is lots of heat.
Ok so you need to put the bolt with the drop of stud and bearing mount on it into the pocket of the set screw/cap screw. If you run the nuts down onto the flat washer as shown the bolt will support itself you just need to make sure its centered good. leave the bolt in the set screw/cap screw overnight. You may need to run a couple of more nuts down the bolt shaft and tighten the nuts against each other, not so much against the set screw. Use the nuts to try to remove the screw.
NOTE: Another secret, there are hex head bolts that can be used as Allen wrenches in a pinch. I have found some metric bolts that will fit into large Allen pockets and even some SAE bolts that will fit into Allen pockets(mostly the larger size screws which are the ones you don't normally carry in your tool kit).

How to Remove a Stripped or "rounded off" Set screws or cap screws

Things You'll Need:

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