Machinist type question?

I have slotted holes in my bumper for my winch mount. I am running a warn 12k and i need the winch at the back of the slots, but when i use it it comes back towards the front of course. Seems like there should be a crescent shaped bit thats pre-made for 1/2” or 5/8” holes that i could tack in and finish to make them round holes. Like a half moon piece. Is this a thing that has a name or do i have to get creative? I tried a couple searches but i dont know what the official name would be if these exist.

If you have any ideas if these are a thing or have a better suggestion I would appreciate it!

 

Hi former machinist here...

That's more of a fabricator question. I mean no doubt you could have something like that machined to fit in your slots. but if I was you I would just mark where I like the bolt in the slot and then buy some thick weld washers and weld them on the underside.

 

Or if you want to go the easy route, and if the slot is covered (by washers on one side and wench on the other)...
Buy some keyway stock (just a small square rod) the thickness of the metal with the slot. Cut a piece long enough to go between the bolt and the front of slot, and put it front of the bolt. It will keep it from sliding forward, with no permanent modification to the bumper.

 

Ah ok, thanks. See weld washer was not in my vocabulary either.. Appreciate it!

 

Thats a good idea also. These are grade 8 bolts so should be a problem, right? Thanks!

 

How do you plan to keep the key stock from bouncing out??

Doubtful the Winch is used to recover shopping carts so lots of bouncing.

I like the weld washers or even 1/2 x13 weld nuts and be done.

 

Tack weld the washers but do so where you can reach that welds with an angle grinder if you ever need to take them off

 

I don't know what his bumper looks like, but I'm imagining a slot that is covered on one side with a washer, and on the other side with a winch. so the slot is not exposed or visible once everything is assembled (thats why I said "if the slot is covered").

If my assumption is correct, it can't bounce out. The bar stock would be stuck in place once everything is assembled. If the bar stock is cut small, it may bounce around a little inside the slot, but once the winch tries to slide the bar stock would stop it and be stuck.

 

You are correct, the holes are slotted, but the washers cover the whole hole. The upper side are the mounts of the winch itself which cover the holes there.

 

so all you need is something to fill the space that is tough enough it won't get crushed or deformed too much. A short piece of bar stock, or a nut from a smaller size bolt, etc.