Anybody out there tried S5 or S7 steel???

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RobertHankins

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Has anybody out there tried S5 or S7 steel on knives?
It is called Shock steel and is suppose to be really tough stuff.
Sure is a Itch to grind thats for sure:rolleyes:
 
Yea I Have Groud Stuff Like That Before Mine is all S 6 at least the Local Tool Steel Supplier Say's that is What this Steel Is !! Not That Bad !! Try 3/16 thick Titanium That is a B *&%** Even with Ceramic Belt's
But Who Said a Knife Maker was Sane ??
Good Luck !!
 
This is a verbatim quote from my written source: "S7 has the highest shock rating of all tool steels .......". It also states: "...it is a very stable air hardening steel .....". I show S7 has a machinability of 95! It appears S5 is a oil hardening steel and it states its machinability is 65. It states "S7 has a little more wear than S5". It talks about using these steels for stuff like chisels - were shock and compression resistance is important. It also states that S5 is difficult to find which may indicate S7 has killed it off (my summation only).

You probably have the analysis for these steels but if you don't, I do - along with temps.

I know you like Bowies, so looks like S7 will make you a real chopper.

Roger
 
Roger,
I looked the analysis up some time ago but can't find it.
If you would be so kind as to share the analysis and the HT and tempering temps that would be great.
Robert
 
Here ya go, Robert. This is right out of the ASTM manual.

S7 AISI
Carbon 0.45 to 0.55
Manganese 0.20 to 0.90
Silicon 0.20 to 1.00
Chromium 3.00 to 3.50
Molybdenum 1.30 to 1.80
Vanadium 0.20 to 0.30 (optional)


Highest hardenability of the S series steels and maximum softening resistance at elevated temperatures. As quenched hardness 60 to 61 HRC.

Forging - start forging at 1950 to 2050 F. Do not forge below 1695 degrees F.

Normalizing – Do not normalize.

Annealing – Heat to 1500 to 1555 F. Use lower limit for small sections and upper limit for large sections. Hold time varies from I hour for light sections to 4 hours for heavy sections. Cool at a rate not to exceed 25 F per hour to 950 F then air cool.

Hardening – Heat slowly and preheat at 1200 to 1300 F and austenitize at 1695 to 1750. Hold for 15 to 45 minutes and quench in oil or let air cool.

Tempering – tempering at 400 to 1150 F will give approximately 57 to 45 HRC.
 
Robert, I do not have the S5 specs. The information posted previously comes from a friend. He had access to the ASTM manuals and he put the information into MS Word and *.jpg files (the tempering graphs) and burned me a CD. I only asked for the steels I was interested in experimenting with, and S5 was not among them. Now, having said that, I did a quick Internet search and found a good link at Crucible's site: www.crucibleservice.com/eselector/prodbyapp/tooldie/labelle.html.

I hope this helps. I can send you individual *.doc or *.jpg files if you need them, just send me an email.
 
Robert,

S5

Carbon 0.60%

Manganese 0.90

Silicon 1.90

Chromium 0.20

Molybdenum 1.30

Vanadium 0.30

Preheat 1200 F./ 650 C.
Hardening (145 deg. F. oil quench) 1725 F. / 940 C.

Temper before steel cools to below 125 F.

As quenched - 61 Rc
300 F. / 150 C. - 60
400 F. / 205 C. - 59
600 F. /315 C. - 57
800 F. / 425 C. - 52


S7

Carbon 0.50%

Manganese 0.70

Silicon 0.30

Chromium 3.25

Molybdenum 1.40

Vanadium 0.25

Same heat treat temps as S5 *EXCEPT S7 IS AIR QUENCHED* - temper before steel becomes less than 125 F.

As quenched - 62 Rc
300 F. - 59
400 F. - 58
600 F. - 55
800 F. - 52

I do not have temper times but you can not temper tool steels too long, only not long enough. I would go three at 2 hours per with a preceeding snap at about 50 degrees F. less.

My written source, Heat Treatment, Selection, And Application Of Tool Steels by Bill Bryson, says of S7: "Its best working range is ontained by tempering at 450 F (230 C.), which produces a 58 Rc hardness".

Tempering between 500 and 700 F. can/will cause brittleness.

Roger
 
Robert,

For the life of me, I don't know why S7 hasn't found it's way into custom knifemaking. I have extensive experience using it in the cold metal forming industry on stamping dies and cold forging tooling. Here in the Mid-West "rust belt" around the great lakes, it is commonly found at tool steel srvice centers and dealers.

It is tough! Even at Rc 52-54 it still has some ductility.
Far superior to O1, A2, D2 in toughness at the same hardness.

I have a confession though....I use to think I knew my share of metalurgy and tool steel....untill I saw a demo by JS Len Landrum at Ron Clayborne's hammer-in last spring. Len proceeded to demonstrate grain refinement through smithing techniques and heat-treating in a coal forge that made me completely throw out the books on traditional "tool-steel" practice when considering knives.

My experience with it in knives is very limited. I had troubles with the heat-treat. I did and edge quench in oil from non-magnetic.....but it didn't seem to harden very well. Not sure where I went wrong but I suspect the troubels started with my make shift coffee-can forge. :(

Please try it...and let us know. S7 was the saving grace for me in the past for tooling.....I can't help to think that it will be incredible in knives....once the details are figured out.

Take care,
Rob
 
Rob,
Good info as always. I have more S5 and just one piece of S7. I found the S7 a BEAR to bandsaw cut even a 5/32nds piece I have. Actually harder than ATS34 on the blades and took longer. S5 was almost as much trouble to grind as it is to cut. Has sort of a toughness built in that requires a new belt and alot of patience to grind a blade. Makes ATS34 look like butter. Then there is the added pleasure of Valadium fumes while grinding...just a little dangerous:eek:

I would like to hear from others who may had experience using it even if it was not for making knives.
 
Epsilon,
Hey never got the HT information...did you forget?
Thanks for your help in this endeavor it is much appreciated. It is all ways great to get expert advice from of one of my fellow knifemakers.
 
Robert,

Sorry, I cannot let go of my info on my specific HT S-5 work. Did you mean general industrial HT info?

Also, are you foring S-5 or using stock removal? What kind of stock (sizes) are you using? I.e flat bar, round, square. I ask because you expressed some difficulty grinding. It shouldn't be much different from anything else if it was properly annealed. Let me know, I'd be happy to help you out in that department. Also who was the supplier any what was the said condition you bought it in?

-Jason
 
Rlinger,

Not to nit-pick but S-5 does not have that much Moly. Got to get rid of about 1%. :p

-Jason
 
S7 knife. one of my dies on the Scotchman Ironworker broke so I called the manufacture to find out the alloy. The guy tells me it's S7. I have never forged it before so I did some research. Air hardens and tempers at 1200 degrees that's really hot! After the tempering process I oil quenched in clean 10W40? The blade turned some crazy colors ! Pinks, electric green in areas golds the blues. All very weird

Charles Cooper
 
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