A8 mod testing

rodriguezryan14 said:
I can be a little extreme sometimes. But what can I say, I like tough blades. That’s why I started making knives to begin with. I’ve been using thinner stock lately because of the toughness I can get with this heat treat. I tend to go overboard , but with the tests I’ve done, I know I won’t have failures in the field with normal use! You should see some of my flex test and hammer impact videos! 🤣

I did find some cpm1v that I wanted to try. But I can’t justify the cost on a sheet right now. I’d rather get a few pieces to test then spend 4 grand on a sheet! That steel has decent enough wear resistance, yet it’s probably tougher than A8 mod. Very interesting!
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Yeah, last month I was looking for 1v too..... It looks perfect for what I wanted. I think Niagra will shear off smaller amounts? but it is still CRAZY expensive! relative to A8mod.
 
Crag the Brewer said:
Yeah, last month I was looking for 1v too..... It looks perfect for what I wanted. I think Niagra will shear off smaller amounts? but it is still CRAZY expensive! relative to A8mod.
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They told me they wouldn’t. They would only sell the entire sheet! 2980 for that sheet, .187 thick. I didn’t ask about shipping, but I’m assuming close to 500 dollars!
 
rodriguezryan14 said:
They told me they wouldn’t. They would only sell the entire sheet! 2980 for that sheet, .187 thick. I didn’t ask about shipping, but I’m assuming close to 500 dollars!
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I'm (thinking) just what I thought I saw on their website?

I'll look again IF i saw that.....
 
I'm not sure of their pricing, seems a bit confusing.... hopefully someone can comment if they will shear smaller amounts? nsm nsm


I guess I was looking at CD1 which is almost ZTUFF, which is still in the same family as 1v.

oops, my memory was a bit off.

I bet that steel is Awesome for what we want. Wish it was more popular!
 
Crag the Brewer said:
I'm not sure of their pricing, seems a bit confusing.... hopefully someone can comment if they will shear smaller amounts? nsm nsm


I guess I was looking at CD1 which is almost ZTUFF, which is still in the same family as 1v.

oops, my memory was a bit off.

I bet that steel is Awesome for what we want. Wish it was more popular!
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according to larrins graph on Patreon. It may be tougher than ztuff, but better wear resistance! That’s a win in my opinion!
 
Crag the Brewer said:
I'm not sure of their pricing, seems a bit confusing.... hopefully someone can comment if they will shear smaller amounts? nsm nsm


I guess I was looking at CD1 which is almost ZTUFF, which is still in the same family as 1v.

oops, my memory was a bit off.

I bet that steel is Awesome for what we want. Wish it was more popular!
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Well according to catra, it may be a little lower than ztuff. But I doubt that’s true
 

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I am about doing another round of notched impact toughness testing, A8M among other steels, what public ht protocol you recommend I use for 2nd 'control' samples? Thanks. One set I will use AKS's coupon 2 ht protocol.
 
BluntCut MetalWorks said:
I am about doing another round of notched impact toughness testing, A8M among other steels, what public ht protocol you recommend I use for 2nd 'control' samples? Thanks. One set I will use AKS's coupon 2 ht protocol.
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Maybe you could use Larrin's 1900F for 30 min, cryo and 2 x 2 hr x 400F. Personally, I would like to also see 1900 with a longer soak time, say 40 minutes, and also 1925 Fahrenheit for 20 minutes.
 
BluntCut MetalWorks said:
I am about doing another round of notched impact toughness testing, A8M among other steels, what public ht protocol you recommend I use for 2nd 'control' samples? Thanks. One set I will use AKS's coupon 2 ht protocol.
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I’d try what everyone else is recommending, 1900 aus temp, I’m soaking a little longer, around 35-40 minutes. And I’m using the low temper with that aus temp!
 
rodriguezryan14 said:
I’d try what everyone else is recommending, 1900 aus temp, I’m soaking a little longer, around 35-40 minutes. And I’m using the low temper with that aus temp!
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BluntCut MetalWorks said:
I am about doing another round of notched impact toughness testing, A8M among other steels, what public ht protocol you recommend I use for 2nd 'control' samples? Thanks. One set I will use AKS's coupon 2 ht protocol.
Click to expand...
I’ve also been using a lower aus temp of 1875 for a 40 minute soak. Trying to get more toughness
 
HPD said:
Maybe you could use Larrin's 1900F for 30 min, cryo and 2 x 2 hr x 400F. Personally, I would like to also see 1900 with a longer soak time, say 40 minutes, and also 1925 Fahrenheit for 20 minutes.
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rodriguezryan14 said:
I’d try what everyone else is recommending, 1900 aus temp, I’m soaking a little longer, around 35-40 minutes. And I’m using the low temper with that aus temp!
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rodriguezryan14 said:
I’ve also been using a lower aus temp of 1875 for a 40 minute soak. Trying to get more toughness
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:thumbsup: avoid an hour of slow ramp is a bonus.

I'll use 1875F 40min aust, cold treatment. If failed to produce 60+rc AQ at -40C, will try dry-ice, LN2 if need to, then temper to target 60rc. btw: Ft-lbf# for a notched specimen will be 2% to 10% of an un-notched specimen, hence 2.5x10mm specimen (-2 mm notched, thus 8mm is effective width) a8m will get ft-lbf range 0.5 to 3.5... My guess 60rc a8m will yields ~1.2 ft-lbf
 
BluntCut MetalWorks said:
:thumbsup: avoid an hour of slow ramp is a bonus.

I'll use 1875F 40min aust, cold treatment. If failed to produce 60+rc AQ at -40C, will try dry-ice, LN2 if need to, then temper to target 60rc. btw: Ft-lbf# for a notched specimen will be 2% to 10% of an un-notched specimen, hence 2.5x10mm specimen (-2 mm notched, thus 8mm is effective width) a8m will get ft-lbf range 0.5 to 3.5... My guess 60rc a8m will yields ~1.2 ft-lbf
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Thank you sir. Let us know how it turns out! I always appreciate your info!
 
BluntCut MetalWorks said:
:thumbsup: avoid an hour of slow ramp is a bonus.

I'll use 1875F 40min aust, cold treatment. If failed to produce 60+rc AQ at -40C, will try dry-ice, LN2 if need to, then temper to target 60rc. btw: Ft-lbf# for a notched specimen will be 2% to 10% of an un-notched specimen, hence 2.5x10mm specimen (-2 mm notched, thus 8mm is effective width) a8m will get ft-lbf range 0.5 to 3.5... My guess 60rc a8m will yields ~1.2 ft-lbf
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Just out of curiosity, why do you think it is that low in toughness compared to 80CrV2? It seems to me just by the numbe it is close to A2 in toughness at the same hardness.
 
Zozo*HC* said:
Just out of curiosity, why do you think it is that low in toughness compared to 80CrV2? It seems to me just by the numbe it is close to A2 in toughness at the same hardness.
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hardness/toughness chart on page 2: AKS A8M spec sheet: https://www.alphaknifesupply.com/Pictures/Info/Steel/A8M-DS-Walter.pdf
10x10mm specimen 60rc 4.5ft-lb, so a subsize 2.5x10mm 60rc is around 1.13 ft-lb <= my 1.2# was a guess from my test data. I think A8M this low because of high alloy could be a liability when dealing with tensional force. well my projection was way-off.

FYI aka FWIW - data thus far for A8MC1 (AKS #2 protocol - specsheet), A8MC2 (1875F 40 minutes soak), A8MHi (high rc), 3VC (1950F 30min), 3VHi (1950F 30min), Aebl (1950F 15min)

'C' stands for 'Control' using public ht protocol

300F tempered RC | Ft-Lb:
A8MC1: 61rc | 2.3
A8MC2: 62 | 0.6
A8MHi: 63 | 0.4
3VC: 63 | 0.8
3VHi: 64 | 0.4
Aebl: 64 | 0.7
80CrV2: 63.5+ | ~0.5

350F tempered
A8MC1: 60rc | 2.7
A8MC2: 61 | 1.4
A8MHi: 61.5 | 1.0
3VC: 62 | 1.3
3VHi: 62.5 | 0.7
Aebl: 62 | 0.8
80CrV2: 62.5 | 2.8

400F TBD
 
BluntCut MetalWorks said:
hardness/toughness chart on page 2: AKS A8M spec sheet: https://www.alphaknifesupply.com/Pictures/Info/Steel/A8M-DS-Walter.pdf
10x10mm specimen 60rc 4.5ft-lb, so a subsize 2.5x10mm 60rc is around 1.13 ft-lb <= my 1.2# was a guess from my test data. I think A8M this low because of high alloy could be a liability when dealing with tensional force. well my projection was way-off.

FYI aka FWIW - data thus far for A8MC1 (AKS #2 protocol - specsheet), A8MC2 (1875F 40 minutes soak), A8MHi (high rc), 3VC (1950F 30min), 3VHi (1950F 30min), Aebl (1950F 15min)

'C' stands for 'Control' using public ht protocol

300F tempered RC | Ft-Lb:
A8MC1: 61rc | 2.3
A8MC2: 62 | 0.6
A8MHi: 63 | 0.4
3VC: 63 | 0.8
3VHi: 64 | 0.4
Aebl: 64 | 0.7
80CrV2: 63.5+ | ~0.5

350F tempered
A8MC1: 60rc | 2.7
A8MC2: 61 | 1.4
A8MHi: 61.5 | 1.0
3VC: 62 | 1.3
3VHi: 62.5 | 0.7
Aebl: 62 | 0.8
80CrV2: 62.5 | 2.8

400F TBD
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Wow, Great amount of test data, Really appreciate for the hard work in that.

I am looking forward to see the 400f test results.

BTW i am still not sure why AKS data sheet is for A8 and their listing is A8Mod. I am using Bestar manufactured A8Mod (BE 2360A8Mod , Chipper), and that one has 8% Cr instead of the listed 5% in the AKS Material. I am not sure but i think Larrin used the same 8% Cr version in his toughness specimens.

The A8Mod at Bestar has same content, except missing the Tungsten, Added 0,5 Vanadium and Cr is raised to 8.5. I would assume the 5% Cr version is tougher even with the missing Vanadium
 
Zozo*HC* said:
Wow, Great amount of test data, Really appreciate for the hard work in that.

I am looking forward to see the 400f test results.

BTW i am still not sure why AKS data sheet is for A8 and their listing is A8Mod. I am using Bestar manufactured A8Mod (BE 2360A8Mod , Chipper), and that one has 8% Cr instead of the listed 5% in the AKS Material. I am not sure but i think Larrin used the same 8% Cr version in his toughness specimens.

The A8Mod at Bestar has same content, except missing the Tungsten, Added 0,5 Vanadium and Cr is raised to 8.5. I would assume the 5% Cr version is tougher even with the missing Vanadium
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To be A8M, its composition should be w/i (a norm) AISI range, per Cr of 8-9% Beside Chuck/AKS already stated 8%Cr in his sept2023 post. I suspect AKS page lists Walter-Metals A8 because absent thereof A8M sheet/mfg-work and the listed A8 sheet contains a lot of great info (worth careful examination if using A8M often).

To avoid thread-hi-jacking , I will bail after post results of 400F.
 
Zozo*HC* said:
Wow, Great amount of test data, Really appreciate for the hard work in that.

I am looking forward to see the 400f test results.

BTW i am still not sure why AKS data sheet is for A8 and their listing is A8Mod. I am using Bestar manufactured A8Mod (BE 2360A8Mod , Chipper), and that one has 8% Cr instead of the listed 5% in the AKS Material. I am not sure but i think Larrin used the same 8% Cr version in his toughness specimens.

The A8Mod at Bestar has same content, except missing the Tungsten, Added 0,5 Vanadium and Cr is raised to 8.5. I would assume the 5% Cr version is tougher even with the missing Vanadium
Click to expand...
The 5%Cr it’s an error. They already clarified that in another thread. It’s 8% Cr.
 
BluntCut MetalWorks said:
To be A8M, its composition should be w/i (a norm) AISI range, per Cr of 8-9% Beside Chuck/AKS already stated 8%Cr in his sept2023 post. I suspect AKS page lists Walter-Metals A8 because absent thereof A8M sheet/mfg-work and the listed A8 sheet contains a lot of great info (worth careful examination if using A8M often).

To avoid thread-hi-jacking , I will bail after post results of 400F.
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I’m kind of lost in the numbers! Is a higher number better? Or a lower number?
 
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