S5 alloy

JTknives

JTknives

Joined
Jun 11, 2006
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I have been interested in S5 for along time but it’s always been in round stock. To me that alloy content makes it look really interesting for a very tough wear resistant steel. Just recently I have sourced it in a sheet which I think would be super fun to play with. I’m waiting on word back about it’s availability and lead time. Just wondering what you guys think Of this steel. Here is the hardness chart and alloy content from the manufacture and a generic data sheet on S5

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Shock steels are cool. Busse used S7 modified and with a special heat treat. They called it SR77. Wicked tough.
 
Bigfattyt said:
Shock steels are cool. Busse used S7 modified and with a special heat treat. They called it SR77. Wicked tough.
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Great! Use it, make some heat treated coupons, grind them and send to Larrin, to toughness testing. It should be interesting to compare S5 and S7 (and others that Larrin has tested so far).
 
hugofeynman said:
Didn’t know this graph. So S5 eclipsed S7 and all the others! And at relatively high hardness! I wander why no one (that I know of) uses this steel! Super tough stuff!
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I think a contributor to this is the fact that it’s normally only found in round stock. I like that it’s rather simple to heat treat compared to the others that Larrin put in the graph. I look forward to running some heat treat tests with it to see what can be brought out of it. I mean look at that thy actually spec a water quench for it. Not sure it would be needed in the thickness we normally work with but it makes me wonder what some cryo treatments could do.
 
I'm in for 50 pcs unless I beat you to it and buy my own plate. Niagara can make it in any thickness, last I checked it was approx 1.5x the price of S7 which is why I haven't tried it already.
 
IIRC, the toughness falls of rapidly as the hardness increases. For a knife, Rc59 would be about the max if you want the toughness to stay high. Larrin's chart stops at Rc59 for S5 and S7 ( probably due to that). However, for a bush/combat zone knife that will take a beating, one made in S5 at Rc58 will be one tough knife.
 
Many of the Iron Worker manufacturers use S5 for their punches. Some use S7. The main reason for using S5 is being able to get a couple more RC than S7. The main reason S5 isn't used anywhere else is it is an oil quench grade and the distortion is big when you try to heat treat flat sections. S7 is the main alloy for flat applications.
 
I talked to my guy and said it’s made in batches and he would get me a batch but I would have to buy the 20ton heat lot lol. I might be able to get in on another order. I’m talking to Niagara about it.
 
Kevin McGovern said:
What do you suppose they mean by "stability in heat treat" on the bar graph?
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Most steels grow when heat treated. Simple high carbon steels grow the most and high alloy steels grow the least, depending on how much retained austenite there is. All steel grows the most after the quench, they shrink some during tempering but not enough to overcome the growth. Stability has to do with how much they grow during heat treating.

Hoss
 
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