Drilling Through 11mm Thickness Steel Beam

[NewToAllOfThis]

Hi,

I have a steel ring beam 203mm x 203mm x 46kg, I need to drill through the steel which is 11mm thick. The holes need to be 20 mm in diameter

 

The problem is that it is very awkward to get to where the holes need to be drilled and a Mag Drill will not get it the correct position for the holes

 

Has anyone used a standard or heavy duty drill to achieve something similar, if so what drill did you use and what drill bits were used.

 

Thanks in advance

 

Colin

[PeterW]

Blacksmiths bits in a decent drill and go slowly building up the size. Bigger the drill, slower the size. 

[Conor]

Just go up in slightly bigger bits. E.g. 4mm, 6mm, 8mm etc. Nice and slow, loads of bodyweight and with some cutting paste. Buy loads of bits. I got a erbauer trade pack from Screwfix. I drilled a couple dozen 8mm holes like this in no time last week with my cordless Makita drill in same weight steel.

 

[joe90]

Try to use a drill with a slipping Chuck, I recently had to drill a few 20mm holes in thick steel and nearly broke my wrist when the bit jammed using my old wolf drill, my SDS drill with Chuck adapter had a slipping clutch and on later holes was a godsend and saved me probable damage. Also larger drills have a greater speed at the edges and are much more prone to overheating so use plenty of lubrication.

Edited April 1, 2021 by joe90

[Mr Punter]

You need to get yourself into as comfortable position as you can and be patient.  There is a sweet spot where it will cut through nicely.  Don't rule out using a core bit and just make a larger hole.

[Onoff]

20mm Starter cutter and keep dipping it it Trefolex, Temaxol, Rocol RTD etc.

 

A new 1/4" Starrett pilot drill will go straight through 11mm steel no messing. 

 

How many holes?

 

I did 42 25mm holes in 5mm stainless:

 

 

With ONE of these Chinesium bits and this was it at the end. In the pillar drill admittedly:

 

[bassanclan]

I do some work at an engineering company and this is everyday drilling for them. There is some good advice already given, slowy increase drill size, use drillng spray/paste, pressure not speed is important. I will add if you want to make life easy for yourself buy some dewalt extreme cobalt drill bits.

[dpmiller]

I'd go with Clive's hole saw option. Less material to remove...

[Onoff]

1 hour ago, dpmiller said:

I'd go with Clive's hole saw option. Less material to remove...

 

Less swarf too. You do of course have the diddy roundel that comes out when you're finished. Hopefully it'll pop out and fall to the floor rather than down the leg of your rigger boot!

 

The best hole saws in my ever so humble opinion are Morse brand. Dark red in colour. Used to get them from Wholesale Fittings. They're are cobalt. Knock the Bosch ones into a cocked hat.

 

A genuine Starrett pilot drill is a great thing to have as a general purpose drill bit for most metals including stainless and they are HsCo so cobalt.

 

1 hour ago, bassanclan said:

I will add if you want to make life easy for yourself buy some dewalt extreme cobalt drill bits.

 

I agree that they are good. The ones with the points on the end? I've been impressed. (I wouldn't use them in this case though).

 

The most impressive (stupid?) thing I've ever seen is a 7' South African labourer drilling an I section column. I couldn't figure why so much smoke. He was drilling the beam with 10mm Dormer HSS drills in a 110V pistol drill. No pilot, no lube, just muscle...and plenty of drills! 

 

However do not skimp on the cutting compound. It does what it says on the tin and makes drilling easier and prolongs the tool life. It's that important imo.

 

However do not skimp on the cutting compound. It does what it says on the tin and makes drilling easier and prolongs the tool life. It's that important imo.

 

?

[Nickfromwales]

I just use bi metal holesaws and a 32mm hole takes just a couple of mins tbh. Needs a lubricant / cutting fluid via pump bottle or aerosol can or the bit will overheat. 
Remember if it’s for cables you’ll need to allow for a piece of conduit or a brass bush so size the hole accordingly because making it a bit bigger after is a royal pita. 

[Onoff]

6 minutes ago, Nickfromwales said:

making it a bit bigger after is a royal pita. 

 

Not if you've made some adapters up!

 

 

 

 

A Porta-Punch hydraulic hole punch is a cracking bit of kit. A lad I worked with had a 110V one. We were punching I beam flanges in a bank and set the basement vault vibration alarms off where it reverberated down through the steel. (We were I add, supposed to be in the bank).

[Mr Punter]

Controversial I know but I have used holesaws and gone in dry.  I just make sure that it is kept cool.

 

I sometimes use a step drill bit for making holes larger but I have only used this on thinner material.

[ToughButterCup]

15 hours ago, NewToAllOfThis said:

...

Has anyone used a standard or heavy duty drill to achieve something similar, if so what drill did you use and what drill bits were used.

...

 

Ya come on here, all innocent like, read a bit,  and then -- -- BAAMMMM.  Suddenly yer an expert. You lot have forgotten more than I'll ever know about drilling steel.