Machinists, I would like to know if a boring bar carbide tip (using repeated passes) would cut through 20 ga steel siding?

If it will what tip would recommend? Thanks Am-O-Tramp

Maybe it's just me but could you elaborate a little more, seems kinda vague. Any carbide tipped boring bar i've ever used will bore a hole in 20 gauge steel plate unless it's induction hardened, in which case you'd want a ceramic insert.

You wound only need cheap tool steel to mill through 20ga siding. I'm not sure why you would need a boring tool or what your situation is with the siding or how 20ga would apply to the siding term. What diameter and tolerance?
A cheap cordless drill and steel drill bit could handle 20ga aluminum or steel.

I must agree with DoomPatrol.  Need more info.  Are you are boring in a 4 jaw chuck?  Are you using it in a milling machine?  How big a bore?  How are you planning on holding the bar and the piece?  Is this production or one part?  E-mail me when you you have more particulars and I will give you some tips.

I am sorry I didn't elaborate more, I thought repeated passes was going to explain my reason for the tips.

I just had a pollbarn built and need the window openings cut out. The poll barn builders use a pair of snips or a reciprocating saw  to cut the siding but that method leaves behind crooked, uneven and jagged edges that look like hell.  

As the siding is already installed I thought I could use a straight edge to guide the carbide tip across the metal siding leaving a more accurate and better looking cutout edge.  If using the tip is feasible for cutting the window holes out of the siding, I intend to silver solder the tip on to a old flat tip screwdriver. Thanks Am-O-Tramp

[url]http://www.feinus.com/nibbler/nibblermain.htm[/url]

I think your making things more difficult than is necessary. Go rent or buy a pair of sheet metal nibblers. Some models won't cut any other way but straight so you should be able to cut a pretty square hole(unless your wanting a round window), just draw it an drill 4 corner holes.

I would think a carbide bit in a std. wood router would handle that just fine.

What ever you do wear good tight sealing safety glasses as thier will be metal bits flying everywhere.

DoomPatrol, the steel siding is attached to the building and there is wood framing for the window behind it.

They force the edge of the siding up enough to get their snips under the siding but its hard for them to cut a straight line the entire length of the cut. If the carbide tip could be drawn across the metal siding and cut through the siding with only a few passes the tip and straight edge method would be the easiest way to make the holes.

The arbor on the nibbler would need more room than I can get by forcing the edge of the siding up.

The problem is the metal siding has to be cut back farther than the edge of the framed out hole.

Adjustable trim pieces slip in behind the siding untill the window gets installed, after the window is in the trim pieces can be pulled up flush to the windows frame.

If it were only a matter of cutting the hole even with the framing lumber there wouldn't be a problem.
         Thanks DoomPatrol Am-O-Tramp

I agree with DoomPatrol, you're making this job harder than you need to.  I'd go with a nibbler or a pneumatic Cut-off Saw.

Are you saying you want to rake a carbide tip across the sheet metal like you would a glass cutter? Neither you nor anybody else on this board is anywhere near strong enough. Carbide works because it's just so damn tough not because it's real sharp, it has a little edge but if i'm assuming right won't do what your wanting. Go get a nibbler, you'll be pleasantly surprised and the job will go much easier and faster than you think.

Thanks Waldo for that idea, I will check into it. I still can us a straight edge to guide the saw. There are six windows going in, each one is 38"W X 37"H, that is a lot of hand snipping.

Thanks to all of you guys. I think Waldo's method is going to be the one I use. I have never did this before or watched anyone do it but I am familiar with a circular saw, level, hammer, and square.

If I would have bought the windows the company offers they would not have been double insulated or double hung and would have cost a hundred dollars more a window. The salesman recommended I use these windows, he said they are much nicer than he offers.

I got a all wood construction window, double hung, double insulated, aluminum clad with a screen for $160 a piece tax included direct from the manufacture, but it's my job to install them. The windows are well made and go into expensive homes from what I was told. I looked at them and agree with the salesman they are well made.


I only wish I could have been more articulate.  Thanks again  Am-O-Tramp

Put an abrasive metal cutting blade in a circular saw (should be about $5 or less at your local hardware store).  Set a shallow depth (because of the wood underneath) and put your straight edge up.  Then let 'er rip!  It's like a hot knife through butter.

Or bring your pole barn to my house and I'll plasma cut it for ya.  [:)]

Thanks Blammo for the offer, but I have a plasma outfit myself, I have the Hypertherm Powermax 600 but the wood behind the siding would cause a problem. What kind of Plasma outfit do you have?

PowerMax 600 is a [i]very[/i] nice machine.  Right now, I just have a Miller Spectrum 300, but eventually will get a Spectrum 2050 because I'd like some more cutting capacity.

I've heard of running a carbide blade backward through sheet metal before, but have never tried it.  I run one forward through aluminum bar stock and it cuts beautifully.  But for steel, I just use the ol' abrasive blade.  Works like a charm.  I still prefer the plasma (or a recip saw), but apparently, you have some sort of weird hang up about setting your barn on fire. [:D]

I should've said earlier that with the wood behind the metal, I think the abrasive blade will work better than the carbide.  You'll want a very shallow blade depth (not much thicker than the metal) and that presents a lot of surface area to the cut.  That's a good thing for the abrasive, but might get messy with the toothed blade.  Anyhoo, I'd rather be there helping you than sitting here at my office.

Abrasive blade it be. I thought of abrasive blade at first but didn't know how far back from the edge the paint may burn back along the edge of the siding that stays, rust problems.

Like I said, I never had to deal with this before and wanted some opinions.  I get the windows next Thursday, I will let you know how it all turned out, pics too. Thanks Am-O-Tramp