Posted on 03/12/2017 9:53:29 PM PDT by Windflier
I'm trying to replace a broken shaft in my sheet metal extrusion machine, but I've run into some machine screws that just will not budge.
They're 3/16th, Allen type, steel screws, mounted in an aluminum block. They have a patina of rust on them, and I already broke a new bit trying to bust the first one loose. I sprayed them all with WD-40, and gave it an hour or two to soak in, but still no go.
Anyone know of a better lubricating product, or some trick I can use to get these suckers to turn?
WD-40 is the wrong thing to use. It is a protectorant, not a loosener. You’ll wait forever and nothing will happen. Remove the WD and get some Liquid Wrench and apply it. After little while, you should get action.
Jeweler’s torch (Ace Hardware) - heat them, let them cool and they will unscrew if you haven’t messed up the heads too much.
Almost 200 posts about an alen screw.
A bunch of Gearheads, FR is a haven for Gearheads.
It’s all starting to make sense now.
Avon’s Skin-So-Soft.
Ditto on the Kroil. The stuff is magic. I can only find it online. Google it.
Yes, that's it. I learned that from working in the oilfield as well. Helped a friend out and he taught me.
wire EDM. just kidding.
We have a winner!
quite welcome. You’ve had a lot of good suggestions from others. Seems like most times I work on my old stuff there is always one nut or bolt that just wants to be a problem.
Are you serious? The Avon’s works to keep my hands from cracking and chapping in these Pennsyltucky winters; but loosening corroded bolts....? Besides Liquid Wrench there a product called “Knock ‘er Loose” if they still make it.
1. Quit worrying about what is the best penetrating product or weird homemade formulas and just go get the PB Blaster. It's real hard to find - Not. Auto parts place, Home Depot, Lowe's, Walmart, hardware store, etc. PB should be in your standard maintenance supplies.
2. Soak the screw over night. As another poster advised, wrap a soaked rag over the screw if needed to keep the screw wet with PB.
3. Call in a machinist. You don't appear to have the tools or experience right now to deal with this. Look over their shoulder and learn for next time.
4. Time is $$$. How much time have you spent on this? How many $$$ are lost by machine downtime? If qualified staff and tools are not on-site then you need to have both a machinist and an industrial electrician on call 24/7 to keep the machines running. Stuff breaks. Stuff repaired or maintained by persons outside their skill levels is a recipe for more breaks and safety hazards.
Botox, loosened her and many others “screws”!
Botox may work for windflier? ;^}
There is no chemical bond formed.
There may be some electrolytic corrosion of the Aluminum. The corrosion products occupy more volume than the metal, so it gets tighter. Heat is your friend in that case.
Patience. Take your time. Lots of good advice so far. Haven’t used Kroil, sounds amazing . The shipyard at Newport News used to use PB Blaster which is decent.
Another method would be to drill out the “head” of the Allen bolt. Collapse the head of the bolt, remove block, use pliers to remove shank of bolt. This requires a good drill bit and a steady hand.
I have used carbide deburring bits in die grinders to accomplish the same.
Good luck! Let us know what works.
Kroil works great with frozen or rusted-in steel fasteners in steel or cast iron threads; less well in aluminum
If you can heat the aluminum threaded part to where it's just barely too hot to touch, the difference between the two metals expansion rates may do the trick. Touching the hot area with a candle and letting the liquid wax flow into the threads helps sometimes.
Alternately: get an impact driver at a motorcycle shop and have them show you how to use it. Alterna
If that doesn't work, try using a small propane torch to heat the shaft. The difference in thermal expansion of aluminum and iron will break the bonds between them, allowing you to remove the setscrew..............
I resemble that remark!
CRC makes Knock’er Loose which you can purchase at Grainger.com. It has a freezing agent which allows the solvent to penetrate the fastener, fitting or shaft. I have used it successfully many times (sometimes you will have to apply it twice if the item is encrusted with corrosion or mineral build-up).
Ez-out them, about a minute per hole. Never-seize on new screws.
Just in case someone has put a steel screw into aluminum with Loctite(idiotic,but it’s been done)then you’ll need heat to break the Loctite loose.
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