# Drilling Holes in Steel



## Inner10 (Mar 12, 2009)

I've got about a hundred 7/16" holes to drill in an H-Beam. I know a punch would be fastest but I'm not about to invest that kind of money.

I ordered up a set of these:

http://www.hougen.com/cutters/sheet-metal-hole-cutters/Rotacut-sheet-metal-hole-cutters.html










Anyone know a faster way without substantial investment in equipment?


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## MarkJames (Nov 25, 2012)

Cheap? Have more than one drill on hand with bits in each. Switch when bits get hot. Cutting oil, etc.


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## rustyjames (Aug 28, 2008)

Those Hougen cutters will put a smile on your face with the first hole you drill.


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## Randy Bush (Mar 7, 2011)

A good quality drill bit will drill a lot of holes fairly quick. Center punch good then drill.


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## P42003 (Jun 15, 2016)

Rent a magnetic base drill so you don't drill at an angle and destroy the carbide inserts.


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## P42003 (Jun 15, 2016)

Is this beam sheet metal thickness or like a regular steel beam. If thick steel beam you should order the bits with carbide inserts. Also cutting oil.


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## Deckhead (Dec 9, 2010)

If it doesn't have to perfect a cutting torch is really fast.


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## Tom Struble (Mar 2, 2007)

hire someone...


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## dibs16 (Nov 30, 2010)

Did a job over the winter, myself and 1 other guy used our cordless drills for about 80 holes. They were pretty thick joists, maybe 1/2". Bunch of cutting oil, 3/16 pilot and 3/8 finish, maybe 3 hours drilling each.

Wish I had seen those bits then. Just sent the link to my PM just in case another job comes up:whistling


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## JT Wood (Dec 17, 2007)

Get a 450 rpm paddle mixer and use a strap to 
Increase pressure. How thick? I can drill a hole in 3/8 plate in about 20-
-25 seconds.

When I install quonsets I drill hundreds of holes. Lay big one I did I figured I went through about 24' of steel altogether


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## antonioooooooo (Mar 8, 2010)

If the bit gets hot, it's done. Definitely use cutting oil. I think the flanges on I-beams are 1/2" usually, what I've seen on commercial. That's gonna be a bltch no matter what.


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## Hardly Working (Apr 7, 2005)

2nd & 3rd for the magdrill.


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## Easy Gibson (Dec 3, 2010)

Timely thread.

I just had to mount an order ticket holder(think short order cooking) to a stainless steel kitchen counter.

I swear that thing was made of adamantium. Ended up having to hole an awl and a hammer to get it started. Not really glamorous, but it worked. One good shot with the awl, then stepped up from 1/16th all the way up to 1/8th without skipping a 64th. Thank got there were only a couple holes.


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## Inner10 (Mar 12, 2009)

P42003 said:


> Rent a magnetic base drill so you don't drill at an angle and destroy the carbide inserts.


I can't find small bits for a mag drill. The annular cutters all seem to start at half inch.


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## Inner10 (Mar 12, 2009)

P42003 said:


> Is this beam sheet metal thickness or like a regular steel beam. If thick steel beam you should order the bits with carbide inserts. Also cutting oil.


It's an H-beam probably 3/8 to 1/2 inch thick.


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## Inner10 (Mar 12, 2009)

Deckhead said:


> If it doesn't have to perfect a cutting torch is really fast.


They have to be clean as a whistle and I'm working over a finished floor. I don't even want to drip oil while I cut them.


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## Inner10 (Mar 12, 2009)

HardGibson said:


> Timely thread.
> 
> I just had to mount an order ticket holder(think short order cooking) to a stainless steel kitchen counter.
> 
> I swear that thing was made of adamantium. Ended up having to hole an awl and a hammer to get it started. Not really glamorous, but it worked. One good shot with the awl, then stepped up from 1/16th all the way up to 1/8th without skipping a 64th. Thank got there were only a couple holes.


Stainless is a completely different animal. It deform and hardens before the bit can even get through. Elevators have stainless everything so I drill a fair amount of it, and the only way you can tackle it is with carbide.


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## Inner10 (Mar 12, 2009)

Tom Struble said:


> hire someone...


Subbing out small tasks like this isn't cost effective for a number of reasons. In the time I draw up the diagrams to supply to a company to drill the holes I could likely have them drilled myself.


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## Inner10 (Mar 12, 2009)

JT Wood said:


> Get a 450 rpm paddle mixer and use a strap to
> Increase pressure. How thick? I can drill a hole in 3/8 plate in about 20-
> -25 seconds.
> 
> When I install quonsets I drill hundreds of holes. Lay big one I did I figured I went through about 24' of steel altogether


If I had to do that quantity I'd just buy a punch. 

What do you drill em with a twist bit?


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## AustinDB (Sep 11, 2006)

...


Sent from my iPhone using Tapatalk


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## Deckhead (Dec 9, 2010)

Anti-wingnut said:


> Can't a guy just reminisce about his greatest inter net foil without you getting all technical


Hey, Ill argue with ya if you want to but I don't know dick about dick when it comes to steel. The steel guys say something to me and I say sounds good. I just nod my head and ask if they're done with that lull yet.:laughing: Job I was on a few years back contractor wanted to save money and said he'd have equipment on site... well, he had enough for one sub, not all 10of us and the steel dude had one eye... I wasn't going to argue.


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## KillerToiletSpider (May 27, 2007)

I own a magnetic drill, so I would use it.


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## JT Wood (Dec 17, 2007)

Inner10 said:


> If I had to do that quantity I'd just buy a punch.
> 
> What do you drill em with a twist bit?


Yep. Norsemen bits from the bolt supply house. And a bench grinder set up nearby.


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## Inner10 (Mar 12, 2009)

JT Wood said:


> Yep. Norsemen bits from the bolt supply house. And a bench grinder set up nearby.


You must be pretty darn good at sharpening them by now.

How exactly do you use a strap to get more leverage?


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## JT Wood (Dec 17, 2007)

I'll take a pic When I get home


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## JT Wood (Dec 17, 2007)

What position are you working from?


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## Inner10 (Mar 12, 2009)

JT Wood said:


> What position are you working from?


Drilling underneath the beam with hot piece of steel showering my face.


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## JT Wood (Dec 17, 2007)

That sucks

Its raining, but I would normally take a ratchet strap, hook one end to the drill handle.
wrap the strap end around the steel. 
Attach the other side to the drill handle. 
Use the ratchet to "pull" the drill through the steel. 

It would take probably 30 seconds to set up for each hole, but once you are going the strap does all the work. (Tighten as you progress)


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## JT Wood (Dec 17, 2007)

http://strongarm5.com


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## JT Wood (Dec 17, 2007)

Here's a couple pics of what I do.

I never use cutting oil, and the slower the drill the better. I think this guy is 600 rpm. I have an ancient skil that is 450 I think.


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## Pearce Services (Nov 21, 2005)

+1 for the Mag drill.

I just bought one for a job that we would be drilling 5/8" holes in 3/8" wall square tubing 19' off the ground, for a prevailing wage job. 

The magnet makes it safe, there is also a chain to tie off with in case someone unplugs your drill. 

No Doubt it paid for itself on the first job.

You can get a Hougen made in USA for around $900 from Amazon


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## Inner10 (Mar 12, 2009)

Just a little update, after about a dozen holes with my 7/16 Hougen cutter I torqued the drill sideways and the entire bit grenaded. Sadly I really can't blame the equipment because it was my own dumb fault.

The rest of the holes I finished off with a 3/8" aircraft bit then reamed it out with a 7/16 carbide bit.

I tried to drill a hole with a 1/2" aircraft bit but it was useless.

I've pretty well determined that when drilling steel anything 3/8" or smaller a twist bit is crown king. When you get above that you want to use a hole cutter.

7/16 is right on the threshold between a twist bit and hole cutter...


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## Pearce Services (Nov 21, 2005)

Inner10 said:


> Just a little update, after about a dozen holes with my 7/16 Hougen cutter I torqued the drill sideways...


Do you have the Magnetic base and it still twisted?


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## Inner10 (Mar 12, 2009)

Pearce Services said:


> Do you have the Magnetic base and it still twisted?


I was drilling freehand with a cordless drill. I put a strap around the beam like John posted.

I wish I had the strongarm5


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## dibs16 (Nov 30, 2010)

Inner10 said:


> Just a little update, after about a dozen holes with my 7/16 Hougen cutter I torqued the drill sideways and the entire bit grenaded. Sadly I really can't blame the equipment because it was my own dumb fault.
> 
> The rest of the holes I finished off with a 3/8" aircraft bit then reamed it out with a 7/16 carbide bit.
> 
> ...


I always predrill any structural metal with a nice sharp 3/16 bit.. keeps the bigger bits sharper longer since theyre more expensive. Faster in the long run. Always drilling for a 3/8 bolt, I never bother going up to 7/16

Sent from my SM-N920P using Tapatalk


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## Inner10 (Mar 12, 2009)

dibs16 said:


> I always predrill aby structural metal with a nice sharp 3/16 bit.. keeps the bigger bits sharper longer since theyre more expensive. Faster in the long run.
> 
> Sent from my SM-N920P using Tapatalk


Not really what I found. A 3/8 doesn't need a pilot, it will walk through steel peeling off long curls of metal. Probably blasted through 3/8" thick steel in 20 seconds on medium speed. Trying to drill up to 1/2" with a twist was a nightmare no matter the size of the pilor hole. Too big and it bites too much metal, too small it still takes forever to drill.

The bottom line is the amount of volume of material you have to remove is directly correlated to the speed at which you can make a hole.

A 1/4" hole is 0.05sq" SA

A 3/8" hole is 0.11sq" 

A 7/16" Hole is 0.15sq"

A 1/2" hole is 0.19sq"

Let's say your cutter is internal diameter is 1/4" outer is 1/2" you are removing about .14sq" of material instead of .19sq"


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## m1911 (Feb 24, 2009)

Use 135° cobalt twist bit


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## dibs16 (Nov 30, 2010)

Those long curls of steel are all that matter! Whether its me, my drill, or the bits, i seem to never get anything but dust with the 3/8 bits

Sent from my SM-N920P using Tapatalk


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## JT Wood (Dec 17, 2007)

When I sharpen a bit, I get little slices, then after a minute or do I was getting some"strings" that were almost a foot long. I love that


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## Inner10 (Mar 12, 2009)

JT Wood said:


> When I sharpen a bit, I get little slices, then after a minute or do I was getting some"strings" that were almost a foot long. I love that


Do you sharpen the bits freehand on a grinder?


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## JT Wood (Dec 17, 2007)

Yep.

The trick is in what you leave, not what you take off. 

:laughing:


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## Calidecks (Nov 19, 2011)

I do the same freehand.


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## RobertCDF (Aug 18, 2005)

You didn't use a step drill or unibit? I would have used 2 or 3 in rotation and a bucket to cool them off.


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## m1911 (Feb 24, 2009)

Californiadecks said:


> I do the same freehand.


I have a Drill Doctor


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## Inner10 (Mar 12, 2009)

RobertCDF said:


> You didn't use a step drill or unibit? I would have used 2 or 3 in rotation and a bucket to cool them off.


No, they make a messy conical hole. Not a great choice for what I was drilling.


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## Inner10 (Mar 12, 2009)

m1911 said:


> I have a Drill Doctor


Does it trump the bench grinder?


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## Calidecks (Nov 19, 2011)

Can a drill doctor sharpen 5/8 and 3/4?


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## JT Wood (Dec 17, 2007)

Inner10 said:


> Does it trump the bench grinder?


I don't know, I've never seemed to need one.


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## Railman (Jan 19, 2008)

The single biggest trick to hand grinding is to test find the original angle, before actually grinding. Then start out lightly at the back/trailing end, & work toward the cut edge. Do a little at a time, & eyeball results.


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## m1911 (Feb 24, 2009)

Inner10 said:


> Does it trump the bench grinder?


It's easier to get symmetrical cuttting edges at the correct angle.


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## m1911 (Feb 24, 2009)

Californiadecks said:


> Can a drill doctor sharpen 5/8 and 3/4?


I have the 750 model it does up to 3/4"


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## m1911 (Feb 24, 2009)

My drill bits are always sharp. :laughing:
I have several sets. Once I have accumulated enough dull bits, I sit down and sharpen 'em at once, goes pretty fast. I don't buy cheap bits.


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