View Full Version : Sulferized Steel

11-21-2009, 03:16 AM
Hi Guys,

Years ago I was given a chunk of round steel by an old machinist. It cut beautifully!

When cutting, it did not come off in curls, rather, it came off in small fine chips almost the size of #9 shot. After cuts were made, the surface was absolutely smooth.

We lived in a coal mining community (deep mine and strip mine) and he frequently used sulferized steel when fabricating worn and broken equipment parts. He also mentioned that this metal could be nicely heat-treated and often did so if making gears or large pins for end-loading buckets.

Has anyone had experience with sulferized steel and if so, what was your application? Where did you get this metal and did you ever have it heat treated?


11-21-2009, 03:39 AM
if you deliberatley add sulphur you are making one of the free cutting mild steels, it is preferable to use sulphur as its not a neurotoxin so the steelplant workers dont get any thicker![lead is also used]
added as ferrosuphur a so called ferroalloy made in a mini blast furnace, raw S can be added to molten steel but you dont get good recovorey and you gas everyone, somtimes used with a little Nb to modify the inclusions.
Heat treatment depends on the Carbon content amongst other things so if not known then just use for low duty high finish as opposed to structural
not sure about welding as i cant remember restrictions on that, can go 'orange peely' if bending in sheet form.

11-21-2009, 04:39 AM
As far as welding goes, im pertty sure 'free cutting' generaly means 'poor welding'
Brazing/silver soldering may still be viable however.

11-21-2009, 09:59 AM

There are several sulfurized steels to choose from. None of them are supposed to weld very well as the sulfur is basicly a dirt or inclusion distributed in the metal to cause the chips to break apart and provide a little lubricity to the cut. Your material was likely Stressproof or 4150 Mod.

C1215 AND C1117 can be case hardened but not enough carbon to thru harden.

C1137, C1141, C1144 can be thru hardend

C1144 can also had in HT STR or Stressproof app 28 RC

4150 Modified re-sulphurized is also HT STR app 28-32 RC

See the links below. No affiliation to this company as I work for a differnt metal supplier.



11-21-2009, 10:42 PM
Hi Guys,

Much appreciate your replies. I believe I will order some of this. About all I can remember is, that stuff machined really great.

Thanks again,