Best way to drill a 7/8" hole into 1/4" steel.

[Curious Hound]

EDM and water jet both make very nice holes.

 

[Dirtman]

 

[MikeG]

An end mill in a drill press chuck isn't the best idea. Kinda useful IF you are cutting pretty soft materials and you go SLOW. The helix angle on an end mill will cause it to pull INTO the work, whereas a normal twist drill has at least some resistance going into the work, at least till it breaks through at the end and grabs. Anyway that is the reason for the flat on the shank of an end mill, so it can be locked into the collet and not pull out.

Normally end mills are used in collets that match the end mill diameter, although reduced shank end mills certainly exist.

With a drill press, I might try a step drill - carefully. Just 'peck' it a little at a time so the chips clear, with cutting oil of course. You can go too slow in steel, and cause it to work-harden, by the way. Plus going too slow is hell on drill bit cutting edges. Just sayin' .... there's a sweet spot where the chips are nicely formed.

Anyway a good set of drill bits is a worthwhile investment if you are going to do any metalworking at all. As is a drill-bit sharpener.

 

[MikeG]

Ummmm..... why the heck don't you just tap the piece of metal? At a quarter inch thick there should be plenty of thread engagement. Use fine threads.

Think you might be making this too complicated......

 

[Snoranger]

Find someone with an ironworker that can just punch a hole through it.

 

[mikkelstuff]

Use a good quality (Lenox for example) bi-metal hole saw with lots of oil. I have done this for larger holes in 1/4" steel channel iron.

 

[Curious Hound]

View attachment 48558

Nice! Does that come in 7/8” caliber?

 

[MikeG]

12GA solid tungsten slug.....

 

[Curious Hound]

12GA solid tungsten slug.....

That’s smaller than what he wants

 

[MikeG]

That’s smaller than what he wants

Figure at impact the hole will be a little bigger....

But we can always upgrade to 10ga as needed

 

[scotts90ranger]

I second or is it third? the hole saw thing, I think it's 3/4" or 7/8" for bolt on 3 point pins for tractors, I drilled new holes lower on my brush hog frame that's 3/8" bar stock and used a hole saw, quick, easy and clean holes...

 

[Grumpaw]

Use this...

 

[MaicoDoug]

Get some dry moly lockset lube in a tube at the home store. Mix as mix equal parts of moly & motor oil (not synthetic) make it black. thin it with wd40 if needed, place aside. Using a "step bit" with a 3/8ths (not the 1/4" hex) shank spin the cutter slowly and press hard (feeds & speeds) All steel requires a lot of pressure & slow cutter speed. I used this method to cut 1/2" thick cold rolled steel to a good quality 1" hole. The step bit was a 1" step bit cutter from harbor freight. Good junk. I mean good luck.

 

[Dirtman]

Oh god when will it end!

 

[Curious Hound]

Oh god when will it end!

View attachment 48574

Lay the phone on the table. Put your hands in your pockets. Back away from the phone. Far, far away.