Reaming out holes in thick steel?

[FatTire]

I just did this in some 1/2" A36 steel.
I up sized 13/16" holes to fit 7/8" pins.
You can buy a 3/4" "drum sander kit" from ACE hdwr.
ACE item # 2495083.

An even better option is to buy the little drum discs from McMaster Carr.
Their little drum discs are much higher quality than ACE, last twice as long, and are not very expensive.
I bought 10 from them for about $12, still have 6 left.

The McMaster Car package description is: "Spiral No-Lap Band"
I bought 80 grit.
If you go to their website, you will find virtually every size and type you could possibly want

That's something I didn't even think of. I would have guessed it would take forever to remove enough material, but apparently not.
I am using a variable speed AC powered drill but the angle grinder is a good option too. Thanks everyone for the suggestions-- the holes were cut originally with a plasma cutter, they're pretty good but it is obvious how they were done. This isn't critical, it is for a 3 point hitch mount, apparently the holes were for 3/4" pins but this is a heavy attachment -- I will feel better with 7/8 pins. I'll post again when I'm done with some photos.

 

[AWSubie]

No muss no fuss

 

[yomax4]

I've heated red hot and pounded a tapered pin in the hole and it did a nice job in a pinch. Have to do both sides of course.

 

[Sberry]

Another was is,,, use the drill you have to make a little start so a hole saw will stay in and will zip it out with a battery drill. Use a little water for cooling. It will go right thru it. About a minute.

 

[workinonit]

What is the implement and how heavy is it. I can't imagine it being too heavy for 3/4" pins.

 

[FatTire]

What is the implement and how heavy is it. I can't imagine it being too heavy for 3/4" pins.

Snowcutter, approx 1700 lbs

 

[dstig1]

I want to enlarge four 13/16" holes in 1/2" thick steel to accept 7/8" pins. This on a piece of equipment so I have to use a hand drill. I happened to have a 15/16" black oxide bit, not too surprisingly that doesn't work at all. In 10 minutes I only penetrated about 1/8" in one hole. So I need to decide between buying an $80 construction reamer (high speed steel, manufacturer says it is OK for stainless) or pick up a 29/32" cobalt drill for under $50. I'm guessing the reamer would work better even though it is softer. Is that correct?

If you can find a place to secure one close by, a mag drill (magnetic base) gives you a drill press with portability. They can be rented.

 

[Seven Gables]

Whenever I have to enlarge a hole in steel I use a Double Cut carbide die grinder burr. I think you would be surprised how quickly and smoothly they remove material in your application . I bought a set of them years ago and they are worth there weight in gold in some situations . Set of 10 in various shapes only about 50-60 bucks.

 

[Sberry]

A common hole saw and a battery drill get it started and will follow it thru in a minute or 2.

 

[stuckmotor]

If it was me, I'd use a right angle die grinder and an abrasive stone to enlarge the holes. Lots safer and easier on your wrists.

A few years ago my son enlarged holes in hardened steel with PINK stones on a right angle die grinder. The pink stones lasted much longer than the blue ones.