Leaded steel

[kquiggle]

OnlineMetals has a good description:

https://www.onlinemetals.com/productguides/steelguide.cfm

Here's an excerpt:

1144 (Stressproof-equivalent) steel
This material is actually pretty cool, at least for steel. It is a higher-strength alloy than 1018 or A36, but in addition has improved ductility as well. The chief feature of 1144 steel, however, is that it has very low distortion or warpage after machining due to a combination of its chemistry, method of manufacture, and heat treatment. Finally, 1144 is relatively easy to machine, with a machinability rating of 83% of AISI 1212 steel.​

 

[Charles Lamont]

In the UK an 'Emergency number' for steel grading was introduced during WW2. It numbered steels from 1 to 58 in increasing alloy content. A 1955 revision of the original 1941 British Standard, BS 970, introduced postscript letters to the series. In spite of this standard being long since obsoleted, several times over, steel grades in the UK are still widely referred to by En number, becauses the system is simple. Low-carbon, low-alloy, free-cutting, leaded mild steel is En1A.

 

[rmd55]

A specialty steel product produced with an innovative process. StressProof® is produced using a proprietary process that draws the bar through a special die under heavy draft, then stress relieves it in a precisely controlled furnace. Trademark of Niagara LaSalle, may be why it is not available down under.
If you look at the micro-structure of leaded steel you can see the lead dispersed as small pockets of free lead much like carbon in cast iron. Not dissolved in the iron so it acts as a dry lube
Richard

 

[DJP]

Stress relief by controlled heating is still required after welding. I doubt that for hobby machining there is any stress induced but if there is a weld, removing stress before final machining I thought was common practice. When welding a sub assembly there isn't a stress proof steel at least not one that you would bet the company on.
A friend owns a business making jigs for the automotive assembly process. He removes stress after welding and before final machining.

 

[harborfreight8x12]

My personal experience with 1144 StressProof steel. Years ago, my brother-in-law broke the drive axles in both of the motors in his bariatric power wheelchair. I needed a material that meet the requirements for drive axles. 1144 StressProof was the fit. It machined well and the motors served until Medicare replaced them with new motors two years later. So, JMHO, go with 1144.

 

[GailInNM]

1144 is also available as TGP (Turned Ground Polished) for use in Swiss style CNC lathes. It costs more of course but can save considerable time when making some parts as the OD is accurate enough for bearing fits with out any additional work.
Gail in NM

 

[mohavegun]

My favored screw machine stock is 12L14 and I do my own centerless grinding when necessary, I operate 3 Brown & Sharpe screw machines and a Royal Master centerless grinder in my shop. I also like 1045 stress proof.

 

[mohavegun]

Has anyone out there tried PEEK plastic as a material for making piston rings for steam engines? This is an interesting plastic, machines like brass and when burned the chip more resembles glass chips than ash. Wear qualities are off the scale for plastic and it is good with the heat in steam engines...
PEEK is polyetheretherketone.

 

[Shopgeezer]

Where do you get it?

 

[john futter]

Any proffessional plastics supplier will get it for you
It makes Teflon look very cheap

 

[karlw144]

Just googled it.PEEK 2” diameter rod, 12” long. $273 plus s&h

 

[Shopgeezer]

Ouch! Pricey. Teflon is cheaper.

 

[rmd55]

That's why McMaster sells it in 3", 6", 9"as well as foot lengths to 8ft

 

[mohavegun]

Where do you get it?

Hello,
The shop I worked for bought it from "McMaster Carr" corporation in Santa Anna California, they ship worldwide and carry all sorts of things, find them at Mcmastercarr.com .

We made big pump rings out of it, the pumps were working in a steel mill in Kingman, AZ. The PEEK rings outwore the silicon bronze rings by a factor of two times life. The environment was the pumps handled cooling water for the rolling line, the water was heavily contaminated with acids, chemicals and steel particles from the steel, rust, dirt and sand! Some of these pump rings or lantern seals were more than a foot in diameter. Yes, the material is expensive but it is extremely durable, makes Teflon look like butter!

Rod

 

[mohavegun]

My favored screw machine stock is 12L14 and I do my own centerless grinding when necessary, I operate 3 Brown & Sharpe screw machines and a Royal Master centerless grinder in my shop. I also like 1045 stress proof.

Just a further comment about 12L14, it was originally designed for screw machine production for the automotive industry. It is in the 100% machinability index for steels, most others are compared to it! I buy for my shop from FRY steel corp in California... They generally only sell in specific quantity lots but will sell small units, expect to pay for packaging and handling on small orders. I stock it in my shop in .130 and .343 diameters and produce parts which are .125 and .312 diameters from it. I centerless grind this material and will sell small quantities if you are interested. I do not want to make a business of it but it is something available in my shop. I also have 1/4" 6061 aluminum and 26o series brass HEX barstock and can supply that as well if anyone is having problems finding such.

 

[kquiggle]

McMaster Carr has everything - but you pay top dollar. If you shop around the Internet at the "usual suspects" you can find it much cheaper. I found 3/4" Diameter PEEK 450G Rod (12" length) for $25 without looking too hard. Just search ebay or amazon for "peek rod".

 

[Johno1958]

Here in Australia I can not seem to get 12L14 steel but can get S1214 which I believe to have sulphur instead of lead in it. I have yet to use it but wonder at the difference
in machining of the two. I also bought some 12mm PEEK of Ebay, 15 dollars per 200mm from China .Unfortunately I could not get white it is the natural color which is
a very light tan color.
John

 

[Cogsy]

The shop I worked for bought it from "McMaster Carr" corporation in Santa Anna California, they ship worldwide and carry all sorts of things, find them at Mcmastercarr.com .

Unfortunately McMaster Carr will only ship internationally to their "established customers" (meaning something like companies that had an account prior to them making this decision) and refuse all orders from new, non-account, international customers. They won't allow new international customers to open an account either. I'm pretty sure they won't even ship to Canada let alone the rest of the world. It's a pity, they seem to have a good range of stuff.

 

[Johno1958]

I am finding that a lot with US gear even on Ebay. A 10 dollar item and they charge 150 bucks or more to post it. I think they have got such a large domestic market we
would not be worth the hassle down here in Australia not to mention the amount of times they must get ripped off by parcels not delivered or damaged.
Its a shame because of the lack of variety of tools and materials specially if you live in a regional area.
John

 

[SailplaneDriver]

You can get 12L14 from Hobby Metals in small quantities.