On a possibly rusty bolt – anyway it’s stuck beyond my ability to budge it.
This is on a Fiskars extendable-handle lopper, and I want to change the blade, that got the front corner snapped off. The problem is that the head of the bolt is in the form of a flat Phillips screw head, pretty large, and with nothing to grab hold of, even with any of the several vise-grip pliers I have tried. And the nut is a lock nut. I suspect the tool might have been left out in the damp and added a little rust to the locking mechanism of the nut. I have tried a spray called Blaster Multi-Max, and heat, separately and in combination. I finally ended up putting the other nut that holds the blade back in so the tool is at least partly functional.
So how do I get that nut off? I don’t mind destroying the nut, it is probably a standard size of which I can buy another, but I don’t want to destroy the bolt as I’m not sure I will be able to replace it. I can’t hacksaw the nut in a direction that is useful (i.e. parallel to the bolt) because the nut is too close to the surface of the tool. I could try to hacksaw the nut across its thickness and very close to the bolt, but boy that’s going to be a slog, as well as possibly damaging to the bolt, so at this point that is my last-ish resort.
You can get one for about $10 to $15 or so at ye ol local car parts store. I have a set of two of them (one larger one smaller) that I got many years ago. I’ve never needed more than that. That 4 pack from Amazon seems a bit pricy.
I wouldn’t use a Dremel if you want to preserve the bolt underneath. The nutcracker will literally snap the nut in half before you get to the threads. There’s nothing in a Dremel that is going to force the two halves apart, so you can end up easily cutting down into the threads on the bolt if you’re not careful.
You can try using a Dremel tool, larger grinder, or hacksaw to cut a slot in the bolt head and try to use a loosen it with a flat head screwdriver, or anything that long and strong that fits in the slot, assuming there’s enough of the nut to hold onto while you try to turn it. You can try to cut the sides of the nut so it can be gripped somehow.
An impact wrench or driver may remove it if there’s material left for a bit or a slot that you cut like above. Otherwise, destructive removal of the nut is always an option. Not sure what kind of lock nut you have, but it doesn’t take much corrosion to make some of them unremovable.
I purchased a set of sockets for removal of rounded,rusted, or stuck nuts. $20 Both metric and standard sizes. Each socket has multiple “floating” carbide teeth which grab the nut.
I didnt think they would work on a large soft rounded fanbelt nut, but they worked like a charm, the nut was very difficult to access. Saved me hundreds of dollars in towing, and repair fees.
edit: the dremel suggestions are spot on, splitting works also, but loppers would be difficult to hold steady for splitting, even in a vise, Ive had that problem as well. The dremel or other grinder lets you whittle away at it slowly…
You might be able to grind the bolt head off, and just replace the whole bolt/nut combo. If you can lock the tool in a vise to hold it steady, a hammer and chisel could also break the bolt head off.
Don’t discount the possibility of it being reverse threaded, as crowmanyclouds suggests.
ETA: if the rest of the tool is aluminum, the chisel and hammer option might do more harm than good, as the softer aluminum around the bolt might bend/warp before the steel bolt breaks.
