something that will get through a 3/4mm steel plate without taking all day as the cheapo stuff I have is currently taking? thanks

I have vague recollections of a similar question on a thread by @pocster  I’ll see if I can find it. 

Found it

 

 

Wow ! What timing !

Monday I will be drilling my steel !!

 

Bought from Amazon ; plan to sell it when done . Tested ages ago on 1 hole . Slow and steady no issues .

 

Edited March 18, 20233 yr by pocster

Thanks - looks like I need a cobalt bit

3 minutes ago, markharro said:

Thanks - looks like I need a cobalt bit

Bits I also got from Amazon 

 

 

Edited March 18, 20233 yr by pocster

I love drilling holes 

I am just about to buy a new set, as my old ones are pretty knackered, after a bit of research I am heading for the following. We will see….

Any HSS drill bit will do it, as long as it's a real one, not cheap Chinese ones. The import bit is applying the correct pressure, this doesn't come from a hand drill, unless you are drill small holes.  You need coolant also.

Slow speed so you don’t burn it up. The bigger the hole, the slower the rpm - it’s the surface speed that’s key. +1 for coolant/cutting fluid. Also clear the chips if they’re building up. Rotabroach / annular cutter if they’re not tiny holes.

The only own-brand or barely known names i would buy would be for a contractor who forgot to bring any bits, esp for concrete, but i get some to keep him on site. I won't be seeing them again, and don't care.

A known top brand will be many times quicker and end up cheaper. Won't wear out the drill or arm either.

No comment on Milwaukee so i look forward to a report, but the likes of Erbauer have been pretty good so far.

16 hours ago, markharro said:

something that will get through a 3/4mm steel plate without taking all day as the cheapo stuff I have is currently taking? thanks

There was similar thread a few weeks ago, the OP ended up (after breaking / chipping drills) renting a Mag drill and cutter.  At the thickness your talking about this is the best way to go. otherwise the drill will snatch, chip etc or brake your wrists.... 

EDIT., oops, just re read that , not 3/4" inch..   It will depend on diameter of hole, and number. but you can get some  good results with metal hole saw

Edited March 19, 20233 yr by Jenki

Just now, Jenki said:

At the thickness your talking about this is the best way to go. 

3/4 is very thick. Has to be a mag drill. It will take 5 minutes cutting.

It is safer too as you are not pushing into the steel and risking losing balance. 

See if you can get a deal for half a day. Aim for half the listed hire price.

Or get the rental of the bit thrown in.

Nice and steady with mag drill . Occasional wd40 on tip . 
No worries 

Near accident …

 

I wear gloves and proper goggles as this drill spits the metal out .

I wear glasses and the goggles won’t fit over them . So I drill semi blind ….

Decided to turn the drill off but couldn’t see the writing in it which said “ electromagnetic “ . Shit me up a bit when it fell …. 🙄

Before anyone asks no where to tie drill to in event of this or power failure . Anyway who wants a 20 kg drill swing into their face .

You should have drilled another hole above first, to hook the safety line.

 

There are goggles that fit over specs. Worth looking for. I think mind came off some official "look at our project" site visit.   But where are they?

22 minutes ago, saveasteading said:

You should have drilled another hole above first, to hook the safety line.

 

There are goggles that fit over specs. Worth looking for. I think mind came off some official "look at our project" site visit.   But where are they?

Yeah , I’ve got a full face mask ( fine with glasses ) but steams up in 1 second . Done the other holes now . Once each is done ; I leave the drill and magnet running then change glasses . Tbh I think even blind folded I know which switch not to touch .

For the record. Size of hole and thickness of steel, and how long to cut including setting up?

1 hour ago, saveasteading said:

For the record. Size of hole and thickness of steel, and how long to cut including setting up?

Hole 10mm . Depth of steel 20mm

 

Probably once going ( I take it steady ) 3 minutes to cut hole .

 

Cleaning up the metal ‘ splinters ‘ ( they go everywhere- 20 mins .

 

Setting up a few minutes . Turning off magnetic when you shouldn’t means shutting down takes 5 seconds . 😁

Edited March 20, 20233 yr by pocster

I’m working around stuff as we live on site I.e everything gets in the (expletive deleted)ing way . If a complete empty room I could probably do 20 holes an hour maybe by pushing the bit in harder and not fannying around .

My recent experience - 

 

On 19/03/2023 at 09:22, JohnMo said:

You need coolant also.

what do you use for coolant?

19 minutes ago, markharro said:

what do you use for coolant?

I sprayed wd40 on the hole as I go 

2 hours ago, pocster said:

sprayed wd40 on the hole as I go 

I do the same