Extracting A 1/4 inch Machine Screw With A Broken Head

[Rick D]

Hi all. While I was in Santa Catalina Island, a guy next to me fouled his prop on the mooring line and swung into me. His pulpit kept the hull off but one of my stanchions was bent. The stanchion is attached to the hull by a through bolt on the rail and has two inboard leg supports that tap into an aluminum plate in the deck lay up. At least it was a Swan that did the damage .
So, I figured I would have a problem with the 1/4 inch Phillips head stainless screws into the aluminum plate after 24 years. I took my impact wrench to work them. The first one came out fine; the second one stripped the head due to a poor angle (I think). I tried creating a slot, but that didn't work either. So, I drilled off the head.
Any suggestions on removing the shaft of the 1/4 inch screw? I have used easy-outs before but never on something this small. Suggestions welcome! Taking the stanchion to a local body shop to straighten.
(Yea, I know the guys owes me a fix, but this stuff happens and I don't feel good about having a yard do something "this simple".)

 

[Charles Erwin]

Yes Harbor Freight. Obtain left handed drill bit kit. Very cheap Then start smallest like 3/16 or less. The idea is drill out the screw body with a diameter that does not reach the 1/4 threads. Pretty soon the screw body remnants will unwind stuck to the left handed bit.

If it is not obvious the drill motor needs to run reversed for this to work.

Slow and steady does the job. Don't mash the drill and turn slow just enough to cut. No lubrication.

After abut 1000 of these type fixes you too will conclude EZ outs are worthless

Charles

 

[Leeward Rail]

After abut 1000 of these type fixes you too will conclude EZ outs are worthless

+1

 

[Allan12210]

I'm still trying to figure out how to extract the broken EZ out from one of the screws in my raw water pump. When they get that small (< 1/4") they should be called EZ Breaks. Charles has the solution.

 

[31seahorse]

Yes Harbor Freight. Obtain left handed drill bit kit.

I have never been successful using an Easy Out. However, I did not know a left handed drill bit existed! Are you sure "left handed drill bits" aren't in the same category as "left handed smoke shifters" or "Snipe" that were often discussed when I was in the Boy Scouts? (Yes, long, long ago!)

 

[jssailem]

When I replaced the companionway rails this spring I had one screw head break as I was extracting it. Not out enough to get with vice grips or needle nose pliers. So I took my drill and fitted the tip to the drill like a bit. Switched to reverse and applied slow torque. Came out slick as wet leaves

 

[Leeward Rail]

I'm still trying to figure out how to extract the broken EZ out from one of the screws in my raw water pump.

That is problematic but doable with a lot of patience and quality bits.

Better ez outs are hardened enough to make them a real PITA to drill out.
Then again stainless fasteners are too.
I'd gently grind it flat just enough so you can use an automatic center punch to make a dimple dead center.
Then slowly gently methodically drill it out in ever increasing sizes.
My reverse drill bits came in less sizes than my normal drills, so I normally use high quality normal bits initially, then once enough of the metal is removed, switch to a reverse bit.

So I took my drill and fitted the tip to the drill like a bit. Switched to reverse and applied slow torque. Came out slick as wet leaves

Yes, than works in some cases.


Before you drill it out, I try the other option.... if there is enough stud/screw sticking out. A bolt extractor of this design:
(i've got a couple different styles and that style seems to work the best. Mine are not Irwin, and came in 2 kits containing a bunch of different sizes down to small machine screw size)

 

[CaptKimble]

Just a hint for future reference: When I expect a screw to strip while trying to remove such as a steel screw from stainless or a stainless from aluminum, I apply a tiny bit of fine valve grinding compound to the screwdriver bit first, it grips the screw tightly and allows you to put as much pressure as possible, I also spend a couple of days applying something like WD 40 or whatever before even starting the removal process. And yes, I have had a couple strip on me and broken my share of bolts but for the most part these simple steps have worked for me.

 

[agprice22]

If I can still access the beat up head or shaft, I will dremel an X in it and try another screw driver. Otherwise, I have used the screw / bolt extractors with success. I have also broken a few.

 

[capta]

I'm a fan of slow and careful with vice grips, obviously, if you have enough left to grab. I have the bolt grabbers and doubt they will help on what is basically now just a stud. If you had a problem extracting it as a screw because of the angle, then I can't see how drilling will work. You may have to consider drilling it out, refilling the hole w/epoxy and redrilling to the proper size.
I just love it when someone else's ineptitude creates problems for others. Maybe just take it to a yard and charge the Swan.

 

[Rick D]

Thanks everyone for the great suggestions! I had a local body shop tackle the stanchion and they did a good job straightening it. I ordered the reverse drill bits and will hope that works. I also ordered a (small) easy out too but won't rely on it. I'll update how it goes. BTW, the bad angle was the stanchion bent. It won't be a problem now. The head is sheared off at the base, so nothing left to grab.

 

[Rick D]

Update: took the stanchion to a body shop who did a nice job straightening it. Drilled the machine screw with a left hand drill. Tried an easy out but no joy. For an experiment, I tried a screw extractor. Worked like a champ. Thanks for all the suggestions. The guy that hit me should be happy. All done for about $75.

 

[jssailem]

The guy that hit me should be happy. All done for about $75.

He should be ecstatic. You paid the bill. You did all the work. You found expert advise for free. He should be beside himself.

 

[Rich Stidger]

Excellent! If you took pictures for a step-by-step story it could help others.

 

[Rick D]

Excellent! If you took pictures for a step-by-step story it could help others.

Didn't think about it. Besides, the only thing it would have shown is my rear end up in the air for a few hours!

 

[JimInPB]

When trying to get a broken steel or stainless screw out of aluminum, my best results have come from mig welding a nut on the remaining piece of bolt, then turning it out with a wrench as soon as the glow goes to a dull orange. I have gotten countless broken exhaust bolts out of Harley shovel heads this way. The reason this works so well is two fold. First, mig welder wire sticks to the bolt shaft & the nut, but it does not stick to the aluminum. Second, aluminum expands about twice as much as steel for the same change in temperature. This means that when the steel glows orange, it swages the aluminum out of the way a little, then when the steel cools, the pressure is relieved. This breaks the grip between the two.

I once had a Canook machinist bet a gallon of maple syrup that this would not work. A month later, I was tired of pancakes.

The left handed drill bits are fantastic for the silly little screws that hold the ignition gizmos on older Norton motorcycles. In that situation, you have the hardened cone shaped end of the cam shaft to act as a guide & push the bit right into the center of the broken screw. You can't miss. It's a beautiful thing. It's usually a 10-second job.

If you can get on the center of the broken screw & the threads are not totally jammed up, the left handed bits are a great first choice. If the threads are jammed, or you can't get on center well enough, then the welder trick may be the only thing that works reliably without damaging the female threads.

 

[jssailem]

Didn't think about it. Besides, the only thing it would have shown.....

 

[DougM]

Good advice, if only I had a mig welder. I’ve always wanted one but can’t justify the cost.

Now if someone has an idea for removing a hardened allen head set screw with the top broken off from an aluminum adjustment block on my bandsaw...
(Already tried the screw extractor).

 

[JimInPB]

Allen set screws are only hard at the very tip. The rest of the screw is extracted using the same methods as a regular bolt. In the case of a stripped hex socket on the head of a screw, there are special extractors made for that specific purpose They are basically a tapered hex - http://www.wttool.com/index/page/product/product_id/6943/product_name/Sock-It-Out+Flathead+Cap+Screw+Extractors?gclid=EAIaIQobChMIwqHa2P_V3AIVCK_ICh1JUgqsEAQYASABEgICdPD_BwE
Once you get the screw out using this method, avoid temptation & throw the damaged screw away.

When using drill-first extractors, I find that the square ones work much better than the spiral ones. https://www.lowes.com/pd/KD-Tools-5...MI0sCijv7V3AIVGsDICh1Jbw7TEAQYASABEgKbuvD_BwE

If just the hardened tip is broken off of the set screw, then you should be able to break it into pieces using an automatic center punch or other hard tipped punch.
https://www.homedepot.com/p/General-Tools-Heavy-Duty-Automatic-Center-Punch-78/301345941?cm_mmc=Shopping|G|Base|D27E|27-11_TOOLS_&_ACCESSORIES|NA|PLA|71700000034238984|58700003943782712|92700031954542176&gclid=EAIaIQobChMIw8nb3P3V3AIV0-DICh3VpgzlEAQYAyABEgLHjvD_BwE&dclid=CIGUpuP91dwCFQVuwQodXj8Luw

 

[justsomeguy]

Now if someone has an idea for removing a hardened allen head set screw with the top broken off from an aluminum adjustment block on my bandsaw...
(Already tried the screw extractor).

That's a toughie. Parts available?
I've had good luck melting the aluminum away from a siezed object though.