We’ve all found ourselves faced with a badly frozen fastener–a rusted-shut screw, nut, or bolt–at least a few times in our lives. When I was a teen, my friends and I discovered a rusted heap of lawn mowers and some other machinery and metal pieces in a garbage heap. We had dreams of getting a working motor out of it all and building a go-kart. But first we had to get everything apart.
It seemed easy, that first step, but we never got much beyond it. Everything was frozen with rust and all we had were pliers, crescent and socket wrenches. No WD-40, no specialty tools, and we knew nothing of the tricks shared here. We banged, we chiseled, we skinned our knuckles, and we cursed a lot. In the end, we were able to free up some of the parts and we tried to build an engine with what we had, but we never got a working one going.
So, to makers of all ages trying to coax ancient machinery back to life, here are a few things you can try.
Use a Penetrating Oil
Everyone should have a can of penetrating oil in their toolbox and it’s the first thing you should reach for when a wrench and elbow grease don’t do the trick. WD-40 is the most common and widely-trusted brand, but there are many others. When I posted about this topic on my Facebook page, my friend John Ülaszek wrote: “When I was in the Air Force, we used Kroil on fasteners in the hot section of jet engines. Works great.” Read the reviews of Kroil on Amazon and you will see how happy its customers are, to the tune of 435 5-star reviews. When using a penetrating oil, spray it on, let it set (ideally for upwards of an hour or two), then try and to unfreeze your fastener.
Another way of freeing up a frozen screw or bolt is by heating it. Use a blow torch to get it red-hot. The heating will make the bolt expand and then contract and when it does, it’ll loosen the fused bond, hopefully allowing you to extract it.
Knock It Out
Even after you’ve sprayed on a penetrating oil, you may still need help freeing your fastener. And then there are situations where the head has been sheered clean off. Under these circumstances, you can try using a hammer and chisel. Place the blade of the chisel near an outside edge of the fastener and hammer it counter-clockwise until (hopefully) it begins to move freely. [Image from How to Remove a Broken Bolt]
Nut Splitter to the Rescue
A nut splitter is an inexpensive specialty tool. It has a collar that goes over the frozen nut and then there’s a piercing head that you screw into the nut to grab onto it. With the nut engaged with the splitter, you simply turn the tool to free the nut. You can get a nut splitter set online for under $20. [Photo by Dug North]
Here’s a video on how to use a nut splitter.
Use an Impact Driver
Try a Screw Extractor
Welding on a Nut
Another method for freeing a sheered off bolt is to weld a nut to the head-end of the bolt and then use a wrench on the nut to free the damaged bolt. As explained in this Ultimate Handyman video, you don’t have to be a great welder, you just need to tack a decent-enough bond between the bolt and the nut to withstand the torque of a wrench. In the video, he also shows you the chiseling method, using a screw extractor, and using a set of left-handed drill bits to extract bolts and screws.
There are many other methods for freeing up broken fasteners. Do a search on YouTube and you’ll find plenty. What are your preferred methods? Please share in the comments below.