Looking for steel alloy recomendations for a part and where to get in Portland OR

[DavidScott]

I have a customer who likes to supply the material for his parts and is having problems sourcing steel for one part. He usually gets it from McMaster but the last batch he got is cosmetically unfit and I think metalurgically as well. He doesn't remember what alloy he got the last time, still waiting for him to get back to me on this after going through his order history, but for sure didn't get the right one this time. Anyway if memory serves ultimate tensil strength is around 80,000 psi, it is 1/4"x3/4" bar with good surface finish, flat faces, and small corner radiuses. The fixture uses Uniforce clamps so the 3/4" width needs to be +/-.005" ish. It is a clamp to hold parts and the thin tip is the area that may bend if the steel isn't stiff/strong enough. Hardening/carborizing is an option and the parts get chrome plated. I would also like recomendations on where to get the steel in Portland OR as well. I never buy this type of metal so have no good idea of who to buy from locally. As always thank you for any advise.

Here is a photo of some scrap parts showing them and what I consider good as far as the steel goes. He just asked if 304SS would be ok, HELP!!!!

 

[guest]

I'd avoid 304 if it's drilled and tapped.

Hard to recommend a grade without knowing more. 1018 can be carburized, and is available in cold finished that size. Should be minus toleranced- like +0/-.005". But it's not going to be 80ksi, and it's not going to be a bright finish.

1045 would fit the bill, but I doubt you'll find it in 1/4 x 3/4. 1137 might be a possibility.

Pacific Machinery and Tool Steel are my goto guys for steel. EMJ if Pacific can't get something. I'd call Pacific and ask them what they can offer. (503) 226-7656

edit to add: looked in the Pacific book, they list 1/4" x 3/4" 1018 cold finished, +0/-.003" 65ksi.

That's all I see in that small size.

 

[Milland]

Talk to your customer about making this in 17-4 or 15-5 PH SS, at H1050 or so. About 150ksi yield, no problems machining it.

Just be sure the bar is rolled, not sheared from plate. Then get the 3/4" face "Timesavered" (belt sanding finisher), as this is likely the big cosmetic point. The finish will be a nice satin or bright depending on belt and process. No need for plating, which might balance the higher cost of material.

 

[DethloffMfg]

Pacific Machinery & Tool Steel Co might have something in that size. I think they have a lot of ground stock on hand. There's also a Metal Supermarkets in Portland.

That strength, maybe 4140 in some stage of normalized/treated?

 

[Orange Vise]

If quantities are relatively low, consider A2 tool steel and call it a day. Pricier than the alternatives, but with small, lightweight parts, machining time is the dominant cost factor, and ground A2 bars from McMaster or any tool steel supplier can be a lot less finicky, especially if the 1/4 x 3/4 dimensions are finished size.

McMaster-Carr

 

[Milland]

If quantities are relatively low, consider A2 tool steel and call it a day. Pricier than the alternatives, but with small, lightweight parts, machining time is the dominant cost factor, and ground A2 bars from McMaster or any tool steel supplier can be a lot less finicky, especially if the 1/4 x 3/4 dimensions are finished size.

Ground tool steel will have sharp edges along the length, customer wants a radius there.

 

[DavidScott]

Thanks for the replies. I have bought tool steel from Pacific Machinery many times and knew they had some medium carbon steels, just figured there would be better places for the low carbon steel. I will call them to find out what they have. Tolerance on the 1018 looks good and the strength may be enough, it's awful close to what McMaster said the stuff he was getting was. I'm doing 500 so carborizing them would be cheap per part if he wants them stronger.

Not going to make these from ground A2, I only get $3 or so to make these so the price difference in the material would be a big deal.

Are the sides of the PH SS square and nice like those in my photo? Version 1 of this assembly used 2 smaller clamps that were made from 1/4"x1/2" SS so not out of the question. Customer is very picky so all surfaces need to look good.

 

[Milland]

On the PH stock it would depend on the rolling mill, it might take a call to a vendor to determine what the edge condition is. Considering what you're getting for them, I'd hope the customer could forgive some less visible side cosmetics. As mentioned, Timesaving the flat would be easy.

 

[DavidScott]

I make them in aluminum fixtures with aluminum clamps so I am happy to have my customer be picky about the sides of the parts. Run time is 70 seconds per part total so not too bad.

What about 1215 for this part? It certainly is nice to machine.