Novice metal cutter

[bluedog225]

I’ve got some 3/8”x4”x12” angle iron I’d like to cut into 3” strips and use as ”L” shaped brackets. I’ve got a competent oxygen acetylene torch set up and the correct cutting tip for 3/8”.

I‘ve done (very) little cutting and some brazing. While I think I can handle the cuts, I want to put 1/2” holes in the steel for bolts. Lots of holes. I’ve drilled one hole with a pilot hole and step bit. It was ok but not all that quick.

What do you recommend for the remaining holes? Getting some quality mechanics length bits or step bits and setting up the drill press, or trying to pierce useable holes with the torch?

And if I try this with the torch, should I get a smaller cutting tip so I can have a little more control?

Any thoughts appreciated.

Thanks

 

[kbs2244]

IMO oxygen acetylene leaves an ugly cut edge
and that much cutting will take a lot of gas
I would use a chop saw
you could buy a HF one and blades for the gas cost and have a neater bracket

you have the same problem with the holes
oxygen acetylene burned holes will be ugly and not very precise
get your drill press slowed down to metal speed and use it
use a punch and a pilot hole to get accurate spacing

you can use a wood as a spacer and drill the holes on the top surface
no need for long bits

 

[nadogail]

An Ironworker can shear, punch and bend your steel quickly and neatly. The only clean up will be the disposal of what is punched out of the holes and that residue can be sold for scrap.

With an Ironworker you might want to start a business converting steel into brackets and tabs for sale to small fabrication shops.

 

[dogdog]

They do sell 7-1/4 abrasive disc for circular saws ... if it is just a 1 off thing to do.

 

[The Cobbler]

you will use a lot of gas cutting & making holes with a torch.
you are working with some large stuff, it will be time consuming no matter how you do it.
If it was my project I would look at a chop saw or bandsaw for the cuts and a drill press for the holes .

 

[marak]

For the holes, I'd go to a supply house that sells quality products and purchase an 1/8", 3/8" and a 1/2" drill bit. Tell them it is for metal and you want quality, made in USA bits. Drill at a very slow speed with sufficient pressure and cutting fluid. I used a Metabo (made in Germany, not the HPT thingy) drill, but any drill will be just fine, just slow RPM.

This is what I did when I did a seismic retrofit for my house; I bolted my house to the foundation. Using 1/4" steel with about 10 or 12 holes per plate and about 20 plates - about 600 to 720 holes drilled. Lots of holes, but it went fast. I didn't want to use bits from drill indexes that I had, and more importantly, I wanted nice, sharp, bits, which I will resharpen someday. I could see each flute clearly when I drilled these holes.

A Milwaukee portable band saw may work well. This seems to be my goto for metal cutting, even though I have a heap of different tools for cutting metal. An abrasive saw, cut-off wheels, oxy-acetylene, plasma cutter are fantastic, but messy (at least indoors here in Alaska, where we just got 41 inches of snow in the past 12 days, and now it is -5F in the mornings).

 

[PoorUB]

I’ve got some 3/8”x4”x12” angle iron I’d like to cut into 3” strips and use as ”L” shaped brackets. I’ve got a competent oxygen acetylene torch set up and the correct cutting tip for 3/8”.

I‘ve done (very) little cutting and some brazing. While I think I can handle the cuts, I want to put 1/2” holes in the steel for bolts. Lots of holes. I’ve drilled one hole with a pilot hole and step bit. It was ok but not all that quick.

What do you recommend for the remaining holes? Getting some quality mechanics length bits or step bits and setting up the drill press, or trying to pierce useable holes with the torch?

And if I try this with the torch, should I get a smaller cutting tip so I can have a little more control?

Any thoughts appreciated.

Thanks

If you get split point drill bits and have a half ways decent drill press you can drill a 1/2" hole without a smaller pilot hole, I do it all the time.

Semi-wimpy drill press will require pilot holes, but I might go a bit larger than 1/8", probably 3/16" or 1/4" then go to the 1/2". It really depends on the drill press.

As for cutting, a bandsaw would be best. A cutting torch leaves a pretty rough finish that will need a lot of grinding to clean it up if appearance is important.

 

[Pluribus]

Check out Austin Ross' channel on Youtube. Tried to find the specific video he did about burning holes, and it might be one of the segments in this one:

 

[bluedog225]

Thanks everyone. I thought the torch was the way to go. I’ve seen some fast, crisp cuts on u-tube. Looks like I need to rethink that. My big Milwaukee circular metal saw is only rated to 1/4.

I guess it’s time to look at band saws.

I may cut one with the torch just to get the experience and see how it goes. Seems like it would be quick.

Appearance not important. But hole size is.

 

[whateg01]

A handheld bandsaw isn't going to get through 12" of metal. you need at least a 7*12 bandsaw. How many 3" strips are you going to cut?

If you have a good, slow drill press, that's the way I would go. Mine spins about 70 rpm and just slices right through. A sharp drill helps. Also, if you use a pilot, make sure it's big enough for the drill web to fit in the hole. Unless it's a split point, that post if the drill doesn't cut. By the books, 1/2" hss drill should run about 200-380 rpm. I try to stay on the lower end of that, but often go even slower.

If you need to put a 1/2" bolt through the hole, I would suggest drilling a 9/16" hole to help deal with any misalignments.

 

[BillK]

I have never even thought about doing holes like that with the torch. I actually drilled a couple of 1/2" holes in some 3/8 steel today for something I was making at the shop. I used my 20 volt Dewalt drill and was done in about 5 minutes. Used a 1/4" drill first and then right to 1/2". I have decent drill bits and they cut right through.

I know a lot of guys love them but as far as I am concerned the step drills really are not worth a darn. I got a couple for presents a while back and they were pretty much useless on metal.

 

[bluedog225]

I was planning about 40. I’ve got some Norseman bits on the way. Will try 1/4 to 1/2.

 

[PoorUB]

Step drills are great in sheet metal, but 1/8" and above use conventional drill bits.

 

[kwb]

Rent or borrow a mag drill and use annular cutter. Less than a minute per hole.

Torch is okay for cutting but plan on clean up.

Sawzall and metal cutting blade will be cleaner all around

 

[gazza]

If you need accuracy find a local metal company that sells steel, cuts it to size and drills the holes,
my shed (pic on the left) were all supplied like this, the alignment was so good that I didnt need to file or drill out 1 hole for the entire steel frame, money well spent.

 

[Merch1]

As usual here on the GJ the responses to the OP are all over the map.
He specifically asked about oxy acetylene cutting. Why can’t he cut his material and blow his holes with his torch? How is he going to learn how to use his equipment if he doesn’t have a go at it? How do you know that he will use a lot of oxy/fuel? Sheesh!
Maybe try this: use a steel straight edge and practice some cuts with the torch. Every skill takes practice and more practice. As for the holes, practice that too. Trace a washer or something round and try cutting circles freehand. Sure they’re going to be rough when you start out. Practice piercing and cutting a hole from a pierce. A bolt hole doesn’t have to be perfectly round as long as the bolt and washer can do their job. 40 years of torch use and a bunch of years on GJ shakin my head at some of you guys. Rant over, let the games begin.

 

[csp]

My big Milwaukee circular metal saw is only rated to 1/4.

Are you saying it's only for metal that's 1/4" thick?

From Milwaukee's website for the model 6370 I assume you're referring to: "Count on up to 10 gauge sheets and 1/4 in. steel plate cuts, all day, every day. More extreme cuts, even up to 3/4 in. steel plate, are possible when proper operating techniques are used. "

I've cut 1" thick stock with mine without issue.

It this were my project I'd get the holes done first, assembly line fashion and then cut the individual pieces.

 

[mogandave]

As usual here on the GJ the responses to the OP are all over the map.
He specifically asked about oxy acetylene cutting. Why can’t he cut his material and blow his holes with his torch? How is he going to learn how to use his equipment if he doesn’t have a go at it? How do you know that he will use a lot of oxy/fuel? Sheesh!
Maybe try this: use a steel straight edge and practice some cuts with the torch. Every skill takes practice and more practice. As for the holes, practice that too. Trace a washer or something round and try cutting circles freehand. Sure they’re going to be rough when you start out. Practice piercing and cutting a hole from a pierce. A bolt hole doesn’t have to be perfectly round as long as the bolt and washer can do their job. 40 years of torch use and a bunch of years on GJ shakin my head at some of you guys. Rant over, let the games begin.

I'm with you. Dude has the torch, let him learn to use it.

I would burn (or drill) all the holes before I did all the cuts...

 

[Renegade1LI]

Being this is GJ you really should get a stationary bandsaw & a mag drill or punch. But since you have the torch blow the holes first, helps with a templet than use a rafter square as a guide & cut up the pieces. If you're good with the torch you won't have much grinding.

 

[bluedog225]

You are correct about the milwaukee. I misread another part of the manual. Though the cool down times are pretty rough.

 

[strutaeng]

Is an oxy-acetylene torch all you have? If so, have at it and clean it up with an angle grinder. How many are you needing? (I think this has been answered)

Torch leaves a really rough cut edge. Is appearance important? A portable band saw will give a nice cut, but can also use angle grinder or metal chop saw.

OP stated: "I understood" as L4x4x3/8 x 1'-0"... I don't think he's dumb enough to be asking if he's cutting along the 12" line?

For holes, probably just a twist drill bit on a 1/2 corded drill. Drill press would be nice. I thought it was bad practice to step up drill bits because you ruin the edge, no? At least on thick material. Just do a center punch to locate the holes and let the 1/2" drill bit eat metal.

 

[whateg01]

If he meant 4x4 angle, that is a lot different than what I read as 4x12 angle. Also about half the gas needed. OP doesn't say how big of a bottle he has, but if he's cutting more than a few inches of 1/2" material and had one of the little bottles plumbers carry around, he's going to lose pressure before he gets far and you don't want to be spewing acetone.

 

[bluedog225]

4x12 angle. 75 cubic feet bottle

 

[jack stand]

Blue I'll never criticize a guy looking for a project as an excuse for buying tools, but wouldn't a trip to home depot for some shelf brackets save a whole bunch of everything?
I'd save that angle for a better purpose and get your practice on something else.

 

[strutaeng]

 

[whateg01]

Blue I'll never criticize a guy looking for a project as an excuse for buying tools, but wouldn't a trip to home depot for some shelf brackets save a whole bunch of everything?
I'd save that angle for a better purpose and get your practice on something else.

I don't think he ever said what the brackets are for but I didn't get the impression it was something like a shelf. I guess I didn't get the impression that it wasn't either

 

[jack stand]

01 you are right, I turned it into shelf brackets! I try to only make helpful suggestions but it wouldn't be the first time I "filled in the blanks" unintentionally. I think of a brackets and that's where my head goes.

 

[jack stand]

On a more positive level, use a ''fence" for the 4" & 12" cuts, have a slag hammer and a stack of grinding wheels along with a tip cleaning tool. Piercing holes is something that's hard on them.

 

[Joemctag]

An Ironworker can shear, punch and bend your steel quickly and neatly. The only clean up will be the disposal of what is punched out of the holes and that residue can be sold for scrap.

With an Ironworker you might want to start a business converting steel into brackets and tabs for sale to small fabrication shops.

I think that OP wants co cut 3” “long” pieces of the 4” x 12” angle. The angle will be the bend.

 

[whateg01]

I think that OP wants co cut 3” “long” pieces of the 4” x 12” angle. The angle will be the bend.

An iron worker can shear angle. But an iron worker that will shear 4x12x1/2 is going to be huge

 

[bluedog225]

Thanks all. I am making brackets to hold together 2x16 lvl beams. A little tornado resistant improvement for my shed. I got tired of spending so much on Simpson stuff and thought I’d give diy a shot.

Craigslist is a fickle mistress. In hindsight, lighter stock would have been better, maybe 1/4. But this is what I found.

 

[jrsavoie]

For the holes, I'd go to a supply house that sells quality products and purchase an 1/8", 3/8" and a 1/2" drill bit. Tell them it is for metal and you want quality, made in USA bits. Drill at a very slow speed with sufficient pressure and cutting fluid. I used a Metabo (made in Germany, not the HPT thingy) drill, but any drill will be just fine, just slow RPM.

This is what I did when I did a seismic retrofit for my house; I bolted my house to the foundation. Using 1/4" steel with about 10 or 12 holes per plate and about 20 plates - about 600 to 720 holes drilled. Lots of holes, but it went fast. I didn't want to use bits from drill indexes that I had, and more importantly, I wanted nice, sharp, bits, which I will resharpen someday. I could see each flute clearly when I drilled these holes.

A Milwaukee portable band saw may work well. This seems to be my goto for metal cutting, even though I have a heap of different tools for cutting metal. An abrasive saw, cut-off wheels, oxy-acetylene, plasma cutter are fantastic, but messy (at least indoors here in Alaska, where we just got 41 inches of snow in the past 12 days, and now it is -5F in the mornings).

I hardly used my abrasive chop in the last 30 years.
They were the cats *** in 1980.

Don't use the torch much either. Though the last time I had it out, I surprised myself with a clean cut.

I mostly use the portabands, sawzalls and 10" or 6-1/2" metal cutting circular saws.

If you can find, afford, have space for a 1/2 x 1/2 iron worker, and can find one for a decent price. Jump on it.

It's a lifetime tool.

 

[jrsavoie]

An iron worker can shear angle. But an iron worker that will shear 4x12x1/2 is going to be huge

My first girlfriend said, There's nothing wrong with huge.

 

[strutaeng]

I've designed some custom wood joist hangers, usually out of 3/16 to 1/4 plate for ease/economy to fabricate. 3/8" seems like overkill, but if that's all you got, no issues.

The design is pretty simple: kinda like a "saddle," I think the guys in the industry call them. If you use bolts, keep the distance from the ends about 3" and center-to-center also 3". That's a good rule-of-thumb. 1/2" thru-bolts is a good size for wood.

 

[Jlarson]

Do a couple practice cuts to get your settings right and feel for travel speed and pre heat. If you're going to do the holes too get a feel for piercing.

I don't usually do holes smaller then 3/4" with a torch. You can use a big washer as a small circle guide, you can do like 5/8" minimum hole with a flange wizard circle burner too if you want to get a guide.

 

[Bondo]

Thanks all. I am making brackets to hold together 2x16 lvl beams. A little tornado resistant improvement for my shed. I got tired of spending so much on Simpson stuff and thought I’d give diy a shot.

Craigslist is a fickle mistress. In hindsight, lighter stock would have been better, maybe 1/4. But this is what I found.

Ayuh,..... Flame cut 'em to length, 'n just blast a hole through 'em where you want to bolts,....
Once cooled, punch out the holes with a tapered ream of the size you want, with plenty of oil on the ream,.....

 

[htmdude57]

Did I miss it? I don't think anyone suggested cutting it with a plasma cutter? Would leave a better edge than oxy/acetylene torch?

 

[joe49]

Torch will work with practice. My thought is to make a 1/2'' thick tracible template to follow while cutting. Anytime you make more than one piece of anything you should make a torch template, easy too make more of your piece again.

 

[bluedog225]

I’m remote. Only electricity is the genny.

I tried one cut. It was pretty rough as expected. But I learned a lot. Now going back and relooking at the videos stuff makes a lot more sense. Will try again.

Drilling some holes with 1/4 and 1/2 wasn’t bad. Piecing with the torch was a mess. But again, I think I learned what I was doing wrong.

Thanks for all the input and merry Christmas!

 

[whateg01]

Piecing with the torch was a mess.

Piercing with a torch is a mess, especially thicker material like that. What size tip are you using?