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What's the narrowest, thinnest cut you can do via Oxy/Acetylene?

M.B. Naegle

Diamond
Joined
Feb 7, 2011
Location
Conroe, TX USA
I have a hand full of little plates that need a 'C' shaped cut in the middle for a tab to bend out. They're approx. #16 gauge mild steel sheet metal and my first choice would be to do it on a plasma, laser, or water-jet table, but we don't have one in house and I'm considering finding another way to do it before I send it out.

So, as the title says, what's the narrowest cut you can make with an oxy-acetylene cutting touch with the above material, free-hand? What tip would you use and do you have any advise to keep the kerf as clean and small as possible? The smallest I've done prior was 1/4" plate and I think at best I had a 1/8" wide cut, but typically we're going fast and dirty with the torch, so I'm looking to hone my skill a bit here.

We have a mini jewelers oxy/ace rig too that I might play with to see if I can burn a micro slot repeatably.

Worst case, I might be able to get by with a wider slot (up to 1/8") but if It came to that, I'd just mill it out.
 
Rather than freehand it, make a template with defined start and stop points. That will keep some of the wander and width to a minimum. I do this frequently with plasma for dead simple repeated parts as it’s faster than setting up the plasma table.
 
Rather than freehand it, make a template with defined start and stop points. That will keep some of the wander and width to a minimum. I do this frequently with plasma for dead simple repeated parts as it’s faster than setting up the plasma table.

Yup, but I would borrow a plasma cutter to do it with.

Make the template female so you don't stray outside.....
 
That's a good idea. I'll need to settle on a tip so I know what radius it has, but but a little panto-graph guide wouldn't be difficult to make. I wonder if I could also clamp a little edge onto the tip to rest on the guide to help control the depth too?
 
That's a good idea. I'll need to settle on a tip so I know what radius it has, but but a little panto-graph guide wouldn't be difficult to make. I wonder if I could also clamp a little edge onto the tip to rest on the guide to help control the depth too?

How many are you doing ?
 
a triple 0 tip is rated for 1/8" that's the finest I have seen in industrial torches but I think your warpage is going to be terrible just from the preheat. its hard to move fast, and steady enough, on that thin of material to make a smooth cut
 
You are not going to be remotely happy with the cut quality using oxy acetylene on 16 Ga, along with warpage.
Victor equipment makes a cutting tip for sheet metal that has only one preheat orifice.
Only down side is it must be pulled in one direction inline with the preheat orifice and the oxygen orifice.
For straight cutting on sheet metal they work real well.
That said, for quick and clean and cheap, Plasma.
 
You are not going to be remotely happy with the cut quality using oxy acetylene on 16 Ga, along with warpage.
Victor equipment makes a cutting tip for sheet metal that has only one preheat orifice.
Only down side is it must be pulled in one direction inline with the preheat orifice and the oxygen orifice.
For straight cutting on sheet metal they work real well.
That said, for quick and clean and cheap, Plasma.

absolutely seconded!!^^^ and w/ the price of plasma's-why would you use o/a!?-a bottle of acety. is $100 now!
 
The smallest tip we have is a 00, and it was leaving about an 1/8" wide cut on average. I want to get a 000 to try... but it is looking like outsourcing or milling it out will be my only options.

I was hoping to get it done this week. I'll have to see how quickly our local laser table guy can burn it out.

Did I mention this is a volunteer job too?:) They're a superficial piece in a local vintage aircraft. Nothing dimensionaly critical or load bearing, just one of those lovely "make-it-like-the-original" jobs.

My other idea was to use a cut-off Dremel tip and a jewelers saw, which would give the desired control and shape of cut, just would take a little more patience...
 
If...IF...you are running Airco/Concoa/Koike style torch, you can get a "Hi-Speed" tip and the kerf is narrower. I got mine at my LWS of $18 (yes, better than ebay…)
 
If...IF...you are running Airco/Concoa/Koike style torch, you can get a "Hi-Speed" tip and the kerf is narrower. I got mine at my LWS of $18 (yes, better than ebay…)

Our main handles are a heavy duty Victor and a medium duty Victor, but we have a couple other odd ones in the bottom of the welding tool-box. I googled Concoa and wouldn't you know it, we have one! It hasn't been used since it was rebuilt in 98'. It's missing the mfg. tag and the welding shop didn't write it on the repair tag, so as an aside Thank-you for helping me sort that out!

The only tip we have for it reads 144-0, and by the chart I found the standard tips go down to a 00 for 1/8" plate, but there's a special 119 style tip that has 2 pre-heat orifice's straddling the oxy orifice. Is that what you're talking about? Their chart lists it as being for 1/4" plate, but it's the smallest "light pre-heat" tip I see in the catalog.

http://www.concoa.com/docs/ADIS/ADI3870A.pdf
 
Our main handles are a heavy duty Victor and a medium duty Victor, but we have a couple other odd ones in the bottom of the welding tool-box. I googled Concoa and wouldn't you know it, we have one! It hasn't been used since it was rebuilt in 98'. It's missing the mfg. tag and the welding shop didn't write it on the repair tag, so as an aside Thank-you for helping me sort that out!

The only tip we have for it reads 144-0, and by the chart I found the standard tips go down to a 00 for 1/8" plate, but there's a special 119 style tip that has 2 pre-heat orifice's straddling the oxy orifice. Is that what you're talking about? Their chart lists it as being for 1/4" plate, but it's the smallest "light pre-heat" tip I see in the catalog.

http://www.concoa.com/docs/ADIS/ADI3870A.pdf

https://www.koike.com/documents/Product-Brochures/Accessories/CUTTINGTIPS_PGA_ENG_WEB.pdf

Looks like you want a "102-d7 in OO size" tip (scroll way down)

.03 kerf.
And yes, you'll run 100 psi oxygen (don't worry about it)

EDIT: or a plain 107-000 "normal tip" made for 1/16.
 
Just an update: I tried a 000 tip and it was a slight improvement, but still hard to control and still cutting too wide with my skill level. I finished the job using a handful of 1/16" Dremel cut-off wheels.
 








 
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