How To Cut Holes in 1/8” Steel?

[rangerenthiusiast]

Hey, all. So the cab mount bushings on my ’92 Ranger went bad while the PO still had it. Because he never fixed them, the circular holes in the top of the mounts themselves became enlarged. The rest of the mounts are fine, but the sleeves on the new mounts would have all kinds of slop if I installed them with things the way they are. Here’s a pic: https://drive.google.com/file/d/10jLxkpCQYdIlDTo2fARtQlmlG6bDG5U_/view?usp=sharing.

My intent was to take the mounts out, use a hole saw on a drill press to cut out a circular hole where things are bad, then either weld a circular piece of good steel where the bad was removed, or else plate the top of the mount. I know that the latter would raise the cab an 1/8” over stock, but I think I’m fine with that.

Unfortunately, it took me about 2 hours of grinding to get one mount loose, so now I’m going to just jack the body off the mounts, then weld some plate with predrilled holes for the bushing sleeves to go through on top. Here’s the problem: I’ve looked around here for hole saws at places like Lowe’s and Home Depot, but can only find BiMetal ones. My experience with BiMetal drill bits has been that unless the metal is very thin (like tin roofing), BiMetal anything won’t do jack.

Does anyone know what kind of hole saw (diamond dust encrusted?), I’d need to cut through 1/8” steel plate and where I might be able to find them? A torch isn’t an option, as I don’t own one and want a cleaner cut than that.

Thanks for any input!

 

[adsm08]

I just used some large fender washers. They were perfect.

 

[Dirtman]

You can get carbide tipped hole saws at places like McMaster that cut fast and clean BUT, they are fairly fragile. The teeth break off very easily if you don't run them extremely flat and with a very even pressure/speed. Never run them in a hand drill!

For the cost though, I'd just stick with the bi-metal ones. Keep them drenched in oil and you should be able to make 4 washers before the blade dies.

 

[RonD]

I use a step drill bit when I need to make an existing hole larger or back to round, good ones are not cheap but will last you for years.
Yes, lots and lots of oil, heat kills/dulls drill bits of any kind

If drilling up, get a pump oil can and keep pumping oil from above

 

[alwaysFlOoReD]

I second adsm08 advice. Find a large washer meant for 3/4" or whatever hole size you need, and if necessary add an even larger washer under that for support. Weld it on....

 

[adsm08]

I second adsm08 advice. Find a large washer meant for 3/4" or whatever hole size you need, and if necessary add an even larger washer under that for support. Weld it on....

This is EXACTLY how we repaired a couple of my cab mounts. I found a fender washer at a hardware store that fit the snout on the bushing and bought a couple. Then we dropped one in the bottom, welded it there, and when we dropped another on top of it from the top side it laid almost perfectly flush.

The outer edge of the washer did have to be ground down to fit correctly, but that was more time consuming than difficult.

 

[scotts90ranger]

bi metal hole saws work just fine, I recently cut a 3.5" hole in 3/8" steel plate at work (I only have a HFT benchtop drill press, doesn't go slow enough, and hand drilling is a chore with a 1/2" drill) with a Vermont hole saw, the Irwin ones at Lowes and HD work good too, used one of them to drill a couple 7/8" holes in the 3 point frame on my brush hog for my tractor to gain some more ground clearance...

That said, ready made fender washers would save a LOT of time no matter what...

 

[Dirtman]

As another option I have nothing to do at work today lol. PM me and I'll cut some on my Bridgeport and mail them to you.

 

[Curious Hound]

As another option I have nothing to do at work today lol. PM me and I'll cut some on my Bridgeport and mail them to you.

There's an offer that's hard to refuse.

If you decide to cut your own, though, bi-metal blades are fine as mentioned above. It's all in the details. People have been cutting metal with plain high speed steel cutting tools for many, many years.

Get a good quality bi-metal cutter. Make sure it is as close as possible to being perfectly perpendicular to the work piece. If one side catches first it will try to jerk you around and maybe even break the pilot bit. A drill press is best because it gives you the best control. Use a square and make sure the table isn't tilted. Keep rotational speed fairly low to minimize heat buildup. Use cutting oil. Almost any oil you have on hand will be better than nothing. Feed the cutter into the work slowly. That is to prevent it from grabbing and breaking something and also to minimize heat. Make sure the piece you are cutting is firmly clamped in place. You don't want the cutter to grab and start spinning the piece of metal like a giant saw blade, ripping off your fingers and slicing open your belly. Not trying to scare you. A few safety precautions cost much less than a visit to the ER.

With that said, I have cut many holes in electrical boxes and control panels over the years using a hole saw in a hand-held drill. Some have been 1/8" thick. It just takes patience and an understanding of what can or can't be done. I have also used a 6 1/2" hole saw in a drill press several times very successfully.

This message composed solely of recycled electrons. Go green!

 

[JOLENE_THE_RANGER]

bimetal drill bits or holesaws should be fine for 1/8" plate. thats what ive been using for 10+ years on plate and tube.

 

[Ranger850]

I just used some large fender washers. They were perfect.

This should be the end of this thread

 

[rangerenthiusiast]

Hey, guys. Wow, thanks so much for all the great input! Sorry it took me so long to respond. Had a bad gallbladder attack that lasted several days. Second one in a week’s time. Sheesh.

I feel a LOT more confident about using a hole saw now and I’ll probably just buy a spare for the sizes I need, in case I dull them out completely in the process. I’ve been using some left over gear oil as a cutting oil (can’t waste anything when I’m dumping so much into tools).

@ericphoto: I’ll definitely be careful, man. Thanks.

@Dirtman: I’m speechless. Never had anyone make an offer like that before. YOU ROCK.
I should be able to handle it, but THANK YOU!!

@adsm08: This one kind of surprises me. Whenever I’ve bought washers before,
they’ve either been zinc or galvanized, which I’m told I should never weld.
I’d also think they’d be hard to find in 3” diameter and not very strong. I
know I’ve gotta be missing something here...

Again, thank you so much to everyone for all the great advice and helpful input.

 

[alwaysFlOoReD]

The 3" washer is out there. You are right about being careful when welding galvanized metal. Just grind off the zinc coating and your good to go.

 

[scotts90ranger]

You shouldn't breathe in the fumes while welding galvanized, the zinc coating on most washers isn't much but the super galvanized stuff could be bad, welding outside or with a fan blowing away from you should be sufficient to be safe