S7 Steel in comparison to others like 5160

S

Skidoosh

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I stumbled across S7 steel. I can't find a lot about it used in knifemaking. How is it compared to D2, A2, 5160? Just curious, thanks.
 
It's super tough (resistant to chipping or breaking), but doesn't hold an edge well. It's a shock steel used in jack-hammer bits.

Busse has made some blades in S7. I think they call it SR77
 
Awesome for choppers. I have a scrapyard dogfather with a pretty aggressive convex edge. It doesn’t shave, but it’ll cut a 4” -5” tree down in 8-10 strokes. It’s sharp like an axe and a whole day of clearing saplings around my hunting stands has no effect on it. Yeah I could use my 12” battery chainsaw for that, but I’m a knife guy. Chainsaw is lame. SR77 is badass.

5160 (my scrapyard and swamp rat “SR101” blades) do hold an edge better, but patina like crazy without oiling. My SR77 (S7) blades don’t corrode. I take zero care of them.

overall for hard use, (if you’re chopping, cutting, skinning) the 5160 is a better general steel. My skinners are SR101 and my choppers are SR77. I have a 7” full convex grind and edge that is my best overall blade. Swamp rat camp tramp. It’ll chop (kinda), cut, skin, and hold an edge like a razor with just some ceramic touch up after hard use.
 
VJT said:
Awesome for choppers. I have a scrapyard dogfather with a pretty aggressive convex edge. It doesn’t shave, but it’ll cut a 4” -5” tree down in 8-10 strokes. It’s sharp like an axe and a whole day of clearing saplings around my hunting stands has no effect on it. Yeah I could use my 12” battery chainsaw for that, but I’m a knife guy. Chainsaw is lame. SR77 is badass.

5160 (my scrapyard and swamp rat “SR101” blades) do hold an edge better, but patina like crazy without oiling. My SR77 (S7) blades don’t corrode. I take zero care of them.

overall for hard use, (if you’re chopping, cutting, skinning) the 5160 is a better general steel. My skinners are SR101 and my choppers are SR77. I have a 7” full convex grind and edge that is my best overall blade. Swamp rat camp tramp. It’ll chop (kinda), cut, skin, and hold an edge like a razor with just some ceramic touch up after hard use.
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I think Swamp Rat's SR101 steel is 52100 modified with slightly lower chromium and more manganese.
 
Paging G Gossman Knives

mWqnBzx.jpg
 
shqxk said:
I think Swamp Rat's SR101 steel is 52100 modified with slightly lower chromium and more manganese.
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You are correct. I’m not sure what I was thinking.
 
Skidoosh said:
I stumbled across S7 steel. I can't find a lot about it used in knifemaking. How is it compared to D2, A2, 5160? Just curious, thanks.
Click to expand...

Twindog said:
It's super tough (resistant to chipping or breaking), but doesn't hold an edge well. It's a shock steel used in jack-hammer bits.

Busse has made some blades in S7. I think they call it SR77
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Yes, I had SR77 analyzed and it is S7. Heat treated by busse of course, which makes it even better.

Here is what the old thru hardened dogfather could do

wVHyH5G.jpg


gbkWPtw.jpg


I think this may have been Busse's last SR77 blade made several years ago

frfkbUF.jpg
 
Cobalt said:
Yes, I had SR77 analyzed and it is S7. Heat treated by busse of course, which makes it even better.

Here is what the old thru hardened dogfather could do

wVHyH5G.jpg


gbkWPtw.jpg


I think this may have been Busse's last SR77 blade made several years ago

frfkbUF.jpg
Click to expand...
Did it return to straight?
 
DMG said:
Did it return to straight?
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I don't know, but I highly doubt that any steel bent to an astronomical degree like that could even bend back half way, and especially not a thru hardened steel. Think about it, it almost made a full circle and that's considering it is not differentially heat treated and took what looks to be a 4 or 5 ft bar to bend.
 
afishhunter said:
If it did, it passed the British Proof Test for blades.
That one may have been given a spring temper, in which case it probably did return to straight.
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The british proof test isn't even a blemish to this knife. 5" of flex in either direction probably equates to 30 degrees. But since that standard appears to be made for swords the sword angle would be less at 5 inches, more like 10 degrees. If you look at how far that blade flexed it is somewhere in the 120 degree range. The ABS test is 90 degrees without total failure and will not return to true.

here is a quote of the test:
BRITISH PROOF TEST​

Test 1: Hit the cutting edge of the sword or saber HARD on a heavy wood block. The blade must remain straight and the handle, guard and tang, etc, must all remain rigidly in place with no bending, loosening, rattling, twisting, or turning at all or the sword fails.

Test 2: Hit the back of the blade HARD on a heavy wood block. The blade must remain straight and true and the handle, guard and tang, etc, must all remain rigidly in place with not bending, loosening, rattling, twisting, or turning at all or the sword fails.

Test 3: Hit the flat side of the blade hard on the wooden block and the blade must not bend. The blade must recover and come back truly straight. If it bends or takes a ?set? other than straight it must be rejected.

Test 4: Same as test #3 except the other side of the blade is to be struck.

Test 5: Set the point of the sword on a heavy wood block and flex the blade 5" to the left. It must recover to truly straight. If the blade bends or takes a set other than straight I must be rejected.

Test 6: Same as #5 but the blade is flexed to the right.
Click to expand...
 
If I had to trust my life to a blade not breaking, S7. I used jack hammers made of this stuff and I have full confidence. iirc Emerson said he would rather have a dull knife to a broken one.
 
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