Waterjet Cutting - Relative Difficulty Between Steel Alloys?

apt403 · Dec 7, 2016

Pardon the ignorance, but I'm scratching my head over this one and I don't have much experience with the operational characteristics of waterjet.

I've been getting some blanks cut out of 1/4" 1018 CRS. I'm considering switching this part family over to a higher carbon steel like 1095. Received a quote back from the shop I'm using, and the per part price tripled (I would supply the material).

Is a steel like 1095 really that much more difficult to cut with waterjet? The material would be supplied in the annealed condition. It machines about the same as 1018, so I'm wondering if the huge premium is all due to the PITA factor of dealing with customer supplied material.

Thanks.

jbifs · Dec 7, 2016

When I quote, I can load the part, pick my quality and choose the material and thickness. The software is strictly base on the feedrate of the cut. A seasoned operator can tell you there really is no difference, but the guy in the office doesn't. So obviously 1095 would be a slower feed than 1018. But in reality, you could call and tell them to cut it just like 1018 for that cost. You might get a slightly rougher cut finish so that will depend on your tolerances.

rcoope · Dec 8, 2016

That's seems totally wrong. The "material factor" on Omax for A36 which is what we use for all mild steel is 81. 304 and 316 is 80. D2 at RC60 is 54. Cutting speed is linear with this value. I've only cut 1095 which is .020 or so and as far as I recall it cuts the same as other mild steels. You didn't change the thickness did you?

N.B. For reference. aluminum is ~240 and Plywood is like 2400 .

apt403 · Dec 8, 2016

Correct, no change in material thickness.

Thanks for confirming my suspicions. It seemed intuitive that abrasive waterjet wouldn't care too much about the alloy (within reason) regarding cutting speed.

I also shot budgetary RFQs to a couple different shops, and both quotes are in the ball park of what I was paying for the parts in 1018, with the consideration I don't have really solid working relationships with them.

One of the outfits also quoted the parts in high def. plasma for about 2/3rd the cost of water jet, which sounds pretty attractive. I might have to experiment with a short run. Not sure the cost savings is going to be worth having to anneal the HAZ before machining, or just deal with it.

Garwood · Dec 8, 2016

Laser?

I have thicker 4130N parts lasered all the time.

Or depending on what they are have them punched. I would not run 1/4" 1095 on our punch though.

JNieman · Dec 8, 2016

jbifs said:
When I quote, I can load the part, pick my quality and choose the material and thickness. The software is strictly base on the feedrate of the cut. A seasoned operator can tell you there really is no difference, but the guy in the office doesn't. So obviously 1095 would be a slower feed than 1018. But in reality, you could call and tell them to cut it just like 1018 for that cost. You might get a slightly rougher cut finish so that will depend on your tolerances.

I agree with the above.

For extra data points, Flow's tables show a 'machinability' value of:

AL 6061 = 8.62
A36 Steel = 3.42
S/S 304 = 3.19
Inconel 600 = 2.97
Steel 4130 = 2.95

Don't actually have an entry for 1095 yet, so I guess I haven't cut it. For materials not in the list, I either wing it based on intuition, or if it really matters, run a routine to experiment and base the number on cut quality at various settings, and adjust as necessary to hit the ideal number.

apt403 · Dec 8, 2016

Garwood said:
Laser?

I have thicker 4130N parts lasered all the time.

Or depending on what they are have them punched. I would not run 1/4" 1095 on our punch though.

Is your laser cutter local? I'm about 90 minutes north of Portland, it'd be nice if I could avoid shipping these big plates of material.

I wouldn't run 1/4" through my punch, either. Especially this profile - it would take a ridiculous amount of tonnage (for my equipment, anyway).

Garwood · Dec 8, 2016

apt403 said:
Is your laser cutter local? I'm about 90 minutes north of Portland, it'd be nice if I could avoid shipping these big plates of material.

I wouldn't run 1/4" through my punch, either. Especially this profile - it would take a ridiculous amount of tonnage (for my equipment, anyway).

There are a bunch of laser cutters in Portland. I like Versa-Tech for quality and price. Miller engineering is very quick turn and reasonable price, but they screw up a lot.

If I need it tomorrow and I can live with potential poor cut quality I'll go with Miller. If I can wait a few weeks I'll use Versa-Tech.

Atleast a few dozen other laser cutters in Portland area. Probably a bunch near you too. Everyone has a laser these days. Even me, mine just aren't hooked up right now.

apt403 · Dec 8, 2016

Garwood said:
There are a bunch of laser cutters in Portland. I like Versa-Tech for quality and price. Miller engineering is very quick turn and reasonable price, but they screw up a lot.

If I need it tomorrow and I can live with potential poor cut quality I'll go with Miller. If I can wait a few weeks I'll use Versa-Tech.

Atleast a few dozen other laser cutters in Portland area. Probably a bunch near you too. Everyone has a laser these days. Even me, mine just aren't hooked up right now.

Mega Machine in Tumwater is the closest I know of - They've got a Mazak and have done some nice stainless sheet metal parts for me in the past, but it seems like their gun business is bringing in enough cash they don't have to compete on price. Which, great for them. I wish I was in that position more often.

Thanks for the recommendations - Miller is definitely quick. They've already quoted my RFQ, and beat the pricing I've received for air plasma cutting the same part, let alone water jet.

What's the worse screw up you've had?

Hah, hopefully I'll get to join the laser in-crowd one day - A 6kw Amanda sure would look nice next to the ol' Powermax 600.

Garwood · Dec 8, 2016

Miller will say they can do stuff and fail. Like a 1/2" hole through 1/2" A36. Yeah, it's a hole, but not worth paying for. Nobody else has a problem with it.

They seem to have confusion on material often. If, say you want the normal "laser steel" everyone uses but Miller you can't spec A36, they want you to spec "bright 1018" otherwise they will cut it from some rusty shit that was laying outside for years.

If your parts are easy- No holes smaller than material thickness and you supply nice new material then I say give Miller a shot.

Miller is not cheap, they are middle of the road on price.

apt403 · Dec 8, 2016

Hah, alright then. Thanks for that, I needed a laugh. I'll update this thread for future readers if I go through with having their offered sample parts cut out - And shoot an RFQ over to Versa-Tech.

The material is pretty decent in my experience - The best prices I can find for the quantities I'm working with are from a knife making supplier - The stuff I used for protos came bright, pickled and oiled.

adama · Dec 8, 2016

^ Get it cut on nitrogen, aka stainless settings on the laser, it will cost a bit more but the edge quality is a lot better, never cut 1095 so still don't know if that will leave a soft edge, but you kinda need to try it.

B-Mathews · Dec 8, 2016

I use Mohawk in Vancouver for my Laser and forming needs for the last year. Been though most in town in the last few years.LOL Anyways Always great service and price from Mohawk. They do have a $500 min though. I would try to have those parts Laser cut. Water jet is expensive. If you want to stick with Water Jet you can get a price from Larkin there up near you as well.

WaterjetGuy · Feb 1, 2017

Full disclosure: I work for a waterjet equipment manufacturer. I've done tons of test cuts over the years.

I can say with certainty that you're not going to see much difference in cutting 1018 vs 1095 in 1/4" plate for a handful of parts. Thicker plate, 3/4"+ yes, you'll probably really start to feel the speed (and price) difference, mainly because piercing is going to take a lot longer. It has 99% to do with the hardness of the material. 1018 I believe is about a 71 Rockwell, and 1095 is ~92. For comparison, 316 SS is ~91. Have them quote it out of 1/4" ss and see what they come back with as far as pricing.

I just programmed up a 12"x12" square out of steel and stainless, medium quality, 55,000 psi, 14/40 orifice/nozzle. Times to cut were 3:18 and 03:52, so I'd image your 1095 parts to take about 17% longer. Now granted, 30 seconds adds up pretty quick if you're cutting thousands of parts...

Any questions feel free to PM me.

adama · Feb 1, 2017

^ If it take's you 3 minutes i can see why so many places use laser, thats under a minute of laser time on a 4Kw machine.

WaterjetGuy · Feb 2, 2017

^ Agreed, if HAZ doesn't matter and you just need a bunch of parts. Laser has its place. Right tool for the job I suppose. Also - when I'm done cutting that 1/4" piece of steel on the waterjet, I can immediately start cutting a 10" thick piece of titanium, or 3" of glass, or plywood, or HPDE, or pretty much anything else for that matter without even changing any tooling.

Versatility is the name of the game with waterjet.

JNieman · Feb 2, 2017

adama said:
^ If it take's you 3 minutes i can see why so many places use laser, thats under a minute of laser time on a 4Kw machine.

Waterjet is always gonna be slower. But the lasers aren't going to like 2-1/2" 7075 plates very well.. I cut a shiiit load of blanks from that for our 5axis profiling mill. There's a tradeoff between the two. Neither is better/worse than the other, it's a matter of what they can do. We've cut 9" Titanium for someone as a /test cut/ before which was wild. Boss man was pacing the floor the whole time...

But yea, for 1/4 and under, I'd say the lasers will almost always be the better way to go minus the HAZ, if detrimental.

adama · Feb 2, 2017

Get parts laser cut on the stainless settings, the Haze is non or near to non existent, had some 5mm bits kicking around the desk cut this way, but like usual when you want it you can not find it.

Some point it would be really interesting to do some comparisons, yeah im not disputing that 9" titanium and water jet works well, but it sure would be interesting were that cross over point is. Typical 4Kw output laser will happily cut 25mm steel, 15 stainless and circa 12 ish aluminum. My experience with the laser is cutting sub 10mm its more than possible to cut well enough to be able to tap the holes directly. Laser cut 304 stainless and i use to get over 400 holes per tap with nothing more than a tapmatic and cutting oil. Yeah laser cut Haze will take the teeth off a file, but it really does not seam all that hard to cut with carbide or even coated HSS. Certainly nothing like the thickness of hard skin on plasma cut stuff.

TFPace · Feb 2, 2017

JNieman said:
Waterjet is always gonna be slower. But the lasers aren't going to like 2-1/2" 7075 plates very well.. I cut a shiiit load of blanks from that for our 5axis profiling mill. There's a tradeoff between the two. Neither is better/worse than the other, it's a matter of what they can do. We've cut 9" Titanium for someone as a /test cut/ before which was wild. Boss man was pacing the floor the whole time...

But yea, for 1/4 and under, I'd say the lasers will almost always be the better way to go minus the HAZ, if detrimental.

How did the 9" Ti cut?

WaterjetGuy · Feb 6, 2017

Can't remember if this is titanium or a superalloy of some sort but this should give you an idea of what it might look like...

Waterjet Cutting - Relative Difficulty Between Steel Alloys?

Cast Iron

Aluminum

Stainless

Cast Iron

Diamond

Titanium

Cast Iron

Diamond

Cast Iron

Diamond

Cast Iron

Diamond

Hot Rolled

Plastic

Diamond

Plastic

Titanium

Diamond

Stainless

Plastic

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