CPM S9V looks amazing. Probably hard to work and hard to sharpen, but once it is there... <img src="/ubbthreads/images/graemlins/smile.gif" alt="" /> Check out how it compares to M4 in wear resistance and toughness. <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />
CPM S9V I have no interest in CPM S9V for a knife.
While S9V ranks up in the S7 ranges for toughness, it is designed to be hardened at a pretty low hardness range (like S7). So, while S9V can be made VERY tough, it isn't likely to get or hold an edge very well.
Personally, while I think S7's toughness is AMAZING, I am not real fond of S7's edge properties. And while S7's level of toughness can have certain values at times, I generally prefer a knife with VERY good edge property qualities and will generally be VERY happy with something like SR-101 that is not as tough as S7, but MORE than tough enough for my needs while providing much better edge properties and qualities. SR-101 is a better "Balance" of knife properties than SR-77 ***** For "My" preferences. <img src="/ubbthreads/images/graemlins/thumbup.gif" alt="" />
If you want a pry-bar knife, S7 is "plenty" good enough AND really WAY off the charts in toughness enough for that. If you can't break it, what more do you need? <img src="/ubbthreads/images/graemlins/confused.gif" alt="" /> And I doubt S9V has much improvements in edge qualities over S7 and S9V probably costs a LOT more than S7. So, I personally wouldn't have interest in searching for an alternative steel for pry-bar knives.
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M4 seem to be on the opposite end of the spectrum compared to S7 and 9V.
M4 is designed for HIGH hardness and generally run at about 63-64 HC.
S7 and 9V are reletively low hardness steels commonly at 55-57 HC.
Most tough knives are aroud 57-58 these days.
And most sharp smaller field knives are around 59-61.
S7 and 9V are extreme on one end of the spectrum and M4 is extreme on the other end.
Art mentioned:
...... From what I've read CPM M4 is better for big blades. You know we love our mucho grande knives!
I am curious what and where you have read this Art. I think you likely made some semi-false assumptions based on some info you have read. But, this is an assumption on my part.
From what I know about M4, it is in HIGH favor with a lot of competition rope cutters. Their knives blades are long, but I don't think toughness is nearly as important to them as sharpness. I think "Sufficiently" tough with much higher emphasis on edge retention and edge toughness is more important to the competition guys.
Per Crucible, M4 is tougher than D2, but not quite as tough as A2 = Still fairly tough! But, not as tough as many steels we are becoming used to around here for heavy-duty choppers and “longer” knives.
I think I will likely stick to choppers that are tougher, have sufficient edge qualities and a LOT easier to sharpen. I don't want a chopper that is so hard to sharpen. I like SR-101's balance of toughness and edge properties a LOT for my choppers.
I know INFI and S7 are still a LOT tougher than M4 and I am pretty confident 52100, 5160 and similar are also tougher than M4. But, I don’t have specific info to compare these steels to the Crucible steels in toughness. <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />
Plus, hardness level and heat treat are a big part of the equation.
By todays standards and based on the edge qualities and performance, I would argue that M4 is actually WAY more suited for smaller knives where you want extremely sharp edges to stay sharp for VERY long times, rather than larger beater/chopper/prying knives.
I have a Spyderco Mule (small knife) in M4 and love it. I can’t confirm how tough it is, but it is a MEAN slicer. It holds a CRAZY sharp edge. But, I sharpened it and can confirm that it’s 64 HC was a PITA to sharpen.
The Spyderco Mule is a small fixed blade knife with no scales with about a 3.3125” blade and about 7.625” oal. The knife concept was created to help people test different types of steels. Spyderco also made the Mule in 52100. The M4 version cost about twice the price of the 52100. After grinding on the M4 to reprofile the edge and assuming the MUCH higher Crucible price for Crucible steel, I can see why it cost so much. It is MUCH harder to grind than 52100.
I don’t have exact info to support, but I assume 52100 with Busse heat-treat is still tougher than M4. And while Busse SR-101 holds an awesome edge, I assume M4 holds an edge longer. But, SR-101 is WAY easier to sharpen.
I haven’t done a side by side, but the Spyderco M4 is about as hard to sharpen as I remember the Busse 154CM was to sharpen. Neither is easy.
From what I remember, 154CM is a bit trickier - hard to explain and may have just been a learning curve on my part.
M4 wasn't so tricky as just requires a lot more time and probably better compound media. Diamond paste or similar higher quaility and harder abrasive compounds might be the trick for M4 and ZDP189 type steels. <img src="/ubbthreads/images/graemlins/confused.gif" alt="" />
Personally, I like the M4 based on the little familiarity I have with it so far. But, I am VERY confident I have NO interest in M4 in a larger than 5.5” blade.
Shorter than 5.5” and I would like to try some more.
To me, M4 is an AWESOME slicer blade steel, but NOT ideal for choppers, prying, etc.
However, it is EXPENSIVE!!!!!! - And contradicts Dan’s and Scrap Yard’s business model on value.
I would bet money against Dan using M4.
I would describe M4 as a “Boutique” steel and something only certain custom knife makers who are willing to “Wrangle” with it’s hard to grind properties might consider working with.
I think anyone who wants M4 should expect to need to look elsewhere.
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