Help, need ideas to remove wedged set screw.

Rubbermachinist · Feb 12, 2021

Hello, new to the forum
Rubber machinist to a manufacturing plant in central California.
Rubber compression molding is what we do, mainly oilfield with some agricultural work.
Anyways,

A compression mold was ran with way to much pressure. The set screw was wedged on to the steel plate, it’s stuck. The set screw needs to be removed so a 1 foot long steel rod would thread on like a handle.

Alen key just twists, impact wrench doesn’t do anything, tried drilling it out but drill bits just bounce around and don’t do anything. Maybe I’m approaching it the wrong way.

I want to know if there any other options before I go with an angle grinder and grind it out from the bottom and put a new handle in and build it up with weld and grind it flush again.

Sorry for the short details,
Picture for reference.
Edit, can’t seem to post a picture while on my phone.

Rubbermachinist · Feb 12, 2021

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crossthread · Feb 12, 2021

I'm not sure exactly what is going on here but maybe I can help. What are you using an impact wrench on? When you say the allen key is twisting, do you mean it is slipping in the set screw or just twisting as if too much torque is being applied? I am not sure about your plan on grinding the allen off at the bottom and building up something with a weld either. This is one of those situations where someone with some experience needs to be there but isn't. Sets screws are hard little buggers. You would probably need a carbide bit to drill it out. If you don't have access to any carbide bits then get a masonry bit and sharpen it on a green wheel. If you don't have a green wheel then just get a carbide bit. I'm sorry for not being able to provide more help but the devil is in the details and the details are missing.

Gordon Heaton · Feb 12, 2021

I, too am not clear on the twisting allen wrench comment. The socket shown is in great shape (is that the stuck one, or a 'good' one?). What you need is a stub allen key mounted in a square-drive socket adapter. They're usually less than an inch long and won't twist as much as a regular allen wrench. They can also be used with an impact driver and if you warm up the frame it will help.

doug8cat · Feb 12, 2021

So to be clear, your saying what happened is the metal surrounding the set screw has been compressed around said screw "wedging"/compressing it.
I so I would first try some heat. Second if you have the means use a carbide end mill, start with a small size or go big in both cases avoid hitting the hex flats. Remove as much of the screw possible. In my mind this would allow the remainder of screw to collapse a bit allowing the use of some type of screw removing tool of your choice.
You also might try tig welding a large nut on to it and giver hell. This would not be my first choice, I feel doing what I mentioned first might yield better results, because if I am picking up on what your putt'in down something has allow that pressure surrounding the screw, to be reduce.
If you are able to remove a good portion of the middle of screw hit it something like component cooler (found at electronics suppliers) or inverted air duster to get the remainder to contract.
Good luck.

gbent · Feb 12, 2021

First I'd try a hex key with a cheater. Then on the vertical portion of the hex key put the box end of a wrench at 180 degrees to the cheater. Then put a cheater on the box end wrench so its as long as the hex key. Now when you try to loosen the screw you are applying a true torque rather than a bending load as well. Its the same reason tap wrenches have two handles.

Otherwise I'd put a hex nut over it and mig weld it in place. Allow to cool before trying to remove.

Rubbermachinist · Feb 12, 2021

Sorry for the vague details gentlemen.

We put an Allen key with a cheater bar and the Allen key just bent.

The reason we put the set screws is because during the rubber compression molding process the set screw stops the hole from warping or changing shape. In this case, there was too much compression pressure and bent the hole.
There are two set screws on each end, I managed to get one out but the other is almost oval shaped.... these steel inserts are $$$ , it’s ok to get a little destructive to try and save instead of scrapping it
The difficult part I’m imagining is trying to rig it up on a mill for an windmill start cutting into it.
I’m a novice machinist, mostly rubber grinding , occasional steel turning.

Here is the completed part. It’s 1 part of a 2 part set.
Only 2 handles are required but we want to free up the hole just in case the customer wants 4 handles .

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jim rozen · Feb 12, 2021

Drill it out. If the drill just skates the screw is harder than the drill. You need a better drill.

Interrupted cuts are hell on carbide drills. You will need to approach this with a carbide cutter and
probably will need to set it up on a milling machine (horizontal from the looks of it) so you can go at it
with slow careful feed. A bushing set up to keep the drill (if you use a drill) centered is a must-have.

Example of smaller but similar problem. Setscrew harder than a billly-goat's dick. This required a three flute
carbide drill. Obviously your problem is bigger but the concept is the same. Drill needs to be harder than
the item it is being used on.

Rubbermachinist · Feb 12, 2021

That’s what I was thinking of, I used a HSS drill bit. It just skated , once the drill bit hit the a wall , the drill bit just jumped around.
I’m going to order some better drill bits and carbide bits.
The set up is going to be difficult trying to make a rigid and stop it from moving.

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Garwood · Feb 12, 2021

Get better allen wrenches.

On a stuck scale of 1 to 10 that looks like a 1 to me.

Limy Sami · Feb 12, 2021

+ another on better hex keys BUT, trying the key, giove the screw a good rapping with a punch and hammer - a soft steel punch just a tad smaller than the tapping drill.

L Vanice · Feb 12, 2021

EDM machines are commonly used to burn out broken taps and save expensive tooling. One would work on a set screw. They are expensive, so it is cost effective to find a local shop that has one and helps to pay for it by doing outside jobs.

https://www.amazon.com/Remover-Machine-Portable-Through-Setting/dp/B01LMYQEX4

Larry

Rubbermachinist · Feb 12, 2021

Garwood said:
Get better allen wrenches.

On a stuck scale of 1 to 10 that looks like a 1 to me.

Lol I put it on a vise , I’m 190lbs . I was hanging off the end of a cheater bar.
It’s definitely on the higher end of the stuck scale

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kustomizer · Feb 12, 2021

I've had good luck with this type of impact driver, most auto parts stores should have one, sometimes when an allen's hex gets stripped a metric one a bit larger can be ground down to be a tight fit

https://www.amazon.com/TEKTON-2910-...43&hvpos=&hvnetw=g&hvrand=9358917423516279835

ripperj · Feb 12, 2021

Can you weld a big nut to the set screw?

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Garwood · Feb 12, 2021

Rubbermachinist said:
Lol I put it on a vise , I’m 190lbs . I was hanging off the end of a cheater bar.
It’s definitely on the higher end of the stuck scale

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Is there a new participation trophy version?

Illinoyance · Feb 12, 2021

Is the screw in a through hole? If so get a small hole through the screw then use a cutting torch to wash out the remaining body of the screw. Stop when you see the root of the thread. Pick out the remainder of the thread from the part.

rklopp · Feb 12, 2021

Sounds like he's trying to turn a now-oval screw in a now-oval hole. I imagine it is really good and stuck, because an Allen wrench doesn't have enough guts to make the hole and screw round enough again to let the screw turn. That said, an HSS drill ought to be able to drill the screw provided you run at less than 40 ft/min, feed it hard, and use lots of heavy cutting oil or Moly Dee. Should be a piece of cake with a stubby carbide end mill held correctly.

Peter from Holland · Feb 12, 2021

I would use a masonery drill that just fits into the Hex Mentioned before Easy to get hold of . If it breaks is is easier to remove as a all carbide drill Set it up in the drill press Coolant must be used otherwise the silver solder that holds the carbide tio melts Ideal would be to grind it on a diamant stone
Grind it as much as possible like a normal drill So positive Not negative like the masonory drill is normally
By drilling a small hole you remove the point of the setscrew relaxing it a bit With the hex still in tact you can now try to unscrew it

Peter

BoxcarPete · Feb 12, 2021

Just out of curiosity, if the mold is deformed badly enough to trap the set screw, how are you validating that it will still make accurate parts?

Sounds like if you could hollow it out enough, you could drive it through the ovality by letting it deform like a harmonic drive ring.

Help, need ideas to remove wedged set screw.

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