7-strand lines from McMaster Carr,,,

[Paul Smith]

I've bought from McMaster Carr several times in the past with good results.

Their current menu list two different specs for .015" 7-strand lines:  302 stainless or 304 stainless.

The description seem to be idential, but there is a substantial difference in price.  Both grades have a breaking strength of 40 pounds.

The pricing is up since my last order, and the bulk price is off the menu.

Any metalurgical opinions on 302 vs 304, otherwise I'll just take "best price"?

http://www.mcmaster.com/

[captcurt]

I might be mistaken but I recall that 302 is considered non-magnetic.

Not sure there would be much mechanical difference otherwise but I don't have the data right in front of me.

Curt

[Jim Treace]

My business being medical devices/implants, we utilize numerous types of 300 series SS. The main difference between 302 and 304 is that 302 has a very slight higher carbon content. Not really a big enough difference for CL use. Lower carbon content is usually associated with higher corrosion resistance. Again, not really an issue for normal CL use. Also, all 300 series SS are non-magnetic.
Jim

[captcurt]

Hi Jim:

Yes that's probably true.  I know the chem makeup is very close as is the physical strength.  Many of property differences have to do with composition required for forming or welding process.

Our non mag application was for wire rope in yacht steering systems--since they went near the compass, they needed to be specially made material.  I suspect that most of the 1/4 or 5/16 7 x 19 cable is made of a different series entirely.

Curt

[Jim Treace]

Curt:
Your use probably did require special and higher cost fully annealed cable. When 300 series SS is cold worked such as drawn for wire, cable, rope, bars, etc., this will reduce significantly the normal very low non magnetic properties. The non magnetic properties can be returned by heat stress relieving. But this usually has to be special ordered and is expensive, unless you have on site equipment.  We often have to do this with implants following the polishing process. But then we use the 316 LVM (low vacuum melt), SS.
I am probably getting way outside CL topics.
Jim

[Warren Wagner]

DFTG   (Don't Forget To Google)

Google is the best friend to anyone seeking any kind of information. 

       http://www.machinist-materials.com/stainless_table.htm

This neat and concise chart was the second hit.   A brief description of 302 stainless and 304 stainless is item #2 and #4.  I think this will answer your questions.

Cheers.

Warren Wagner

[Perry Rose]

After reading this post I looked up McMaster-Carr and ordered 300 feet of the 1/64 cable, .016+. I've been wanting to try 70 footers for a while and at $.04 a foot why not. "Shipping charges will be added later". This might hurt a bit.
Perry Rose

[Paul Smith]

. 

       http://www.machinist-materials.com/stainless_table.htm

This neat and concise chart was the second hit.   A brief description of 302 stainless and 304 stainless is item #2 and #4.  I think this will answer your questions.

Cheers.

Warren Wagner

That's the answer I was looking for.  It didn't show up in McC's writeup.

Basically, the 302 includes traces of some alloys that we don't need (compared to 304) and drives a 1-cent per foot (actually 33%) increase in price.

In  the past, McC has been quite reasonable and very quick with shipping.

ps:
As requested by a PM, the full nomenclatutore' is:  3461T2  Type 304 stainless steel wire rope 1x7 1/64" diameter. 

For those with really good calipers, that's 0.01563".   

[taildragger-j3]

Thanks for the "heads-up" I've ordered 300' too. I'm eager to make up a new set.

[Phil Coopy]

Great information Paul, I ordered 500' of .015 & .018, 50' of .024, and a couple of packs of bobbins.

Thanks,

Phil

[Bob Disharoon]

Hi Jim:

Yes that's probably true.  I know the chem makeup is very close as is the physical strength.  Many of property differences have to do with composition required for forming or welding process.

Our non mag application was for wire rope in yacht steering systems--since they went near the compass, they needed to be specially made material.  I suspect that most of the 1/4 or 5/16 7 x 19 cable is made of a different series entirely.

Curt

            From my experience as a yacht rigger, I always used 6/42 cable for steering systems..7/19 is used primarily for halyards and 1/19 for standing rigging..Bob