Stainless Steel Cutting - What Technology?

Dear CNCer’s,

I’m thinking of developing a new business unit in at work for cutting stainless steel.
The product is a set of steel plates to supply the armored car industry and consists of about 150 pounds of (1/8) inch plates, cut and folded in different shapes. (Will try to attach an example photo).



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I understood that there are several ways of doing it with cnc machines with plasma, laser and water jet.
I’d like to get some hints to help find the better cost x benefit technology and I’d very thankful for some knowledge.

Best, Fernão

If you want a lot of identical parts like that, do it with die-stamping and a punch press. The round holes are probably pretty standard; you might need to make a custom die for the rounded rectangle. If every part's going to be different, then it might be worth doing it with a waterjet or something like that.

how many parts a day/week/month do you need made?

Dear Awerby,

The trick is the pieces are not identical, in fact they're tailor made in several different sizes and shapes.
I'll be considering waterjet but the budget is a little high for the payback...

Best,

f

Quote:

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Originally Posted by awerby

If you want a lot of identical parts like that, do it with die-stamping and a punch press. The round holes are probably pretty standard; you might need to make a custom die for the rounded rectangle. If every part's going to be different, then it might be worth doing it with a waterjet or something like that.

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Dear WD40,

Some 300 a day.

Rgs, fernao

Quote:

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Originally Posted by CRO-WD40

how many parts a day/week/month do you need made?

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Consumables and maintenance on a water jet can be high. A laser would be cheaper in the long run.

And how about those high definition plasmas from Hypertherm?

Rgds, gabe

I know very little about plasma other than the one we got rid of was only good for rough cuts in thick material. The water jets took all the plasma work away. All our sheet metal is cut on an old laser.

I second underthetire's comment above - Waterjets will bleed you with the consumables - the garnet and replacement nozzles will have a huge impact on cost.
I would definitely go with a laser; 1/8" ss should be able to be cut with a 3kw machine.

Stainless steel in that thickness range and volume......and likely accuracy requirements.....is a job for laser in the 2 to 3 kW range. It will be an expensive machine to purchase ($400k plus) but over time it will be the most productive and provide the best SS parts.

You could cut these parts with a Hypertherm HPR130XD, however the small features and holes may not be within accuracy requirements. I would use the F5 (95% nitrogen, 5% hydrogen) process for excellent edge quality. The speed would be slower than a 2 to 3kW laser, quality would not be quite as good, but the capital equipment cost would be lower.....likely less than $120k.

Abrasive water jet would provide the best tolerances, no heat affected zone. The productivity would be low (slowest speed of the processes), and the cost per part would be highest. Capital equipment cost for a 50 HP waterjet cutting machine would be in the $200k range.

Jim Colt Hypertherm

Thank you undethetire, ghyman and Jim!
I’ll keep bugging local dealers to see what they can offer here.

Best, fernão

Guys,

Do you think I could arrange a test with with a example piece to find the real difference between the different technologies/suppliers?
I'd take a "drawing" of the piece and a steel plate to each demo and compare later on?
Would this be fair? What "drawing" should I take?

Best, fernao