The NEXT SALE

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Burke said:
I was going to ask the same thing. Assuming SD is standard deviation.
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That's correct.

We have seen some of the little hiccups associated with the beginning of the production of the new alloy so we are skeptically cautious with it.

These numbers are very good and indicate that the heat treat worked without a hitch which indicates a good melt. You can't get this level of consistency without everything being perfect.


I named the company Carothers performance knives instead of Carothers performance cutlery because CPK is a measure of process capability CPC is the communist party of China...


Fun fact: I was certified in Georgia as an ISO9001 quality auditor about 20-25 years ago. I didn't actually work in that role, I was a design engineer, but I was one of the few people in the facility that actually had a college degree so they ran me through with the quality team so it would look better on paper (I had all the prerequisites, it was spring loaded). But I did learn what CPK was and how to calculate it. This CPK statistical analysis indicates five sigma process capability with practically no chance of any out of spec components across the run. Which indicates to me that we're probably pretty good with this batch. :thumbsup:
 
Cpk = Process Capability Index. Adjustment of Cp for the effect of non-centered distribution. It measures how close you are to your target and how consistent you are to around your average performance. CPK <1.00 (Poor, incapable) 1.00< CPK <1.67 (Fair) CPK >1.67 (Excellent, Capable).

PS: sorry, post parallel to Nathan‘s
 
To translate from nerd-speak, that means the hardness range Nathan wants is either above 61.7 or below 63.3 but he's well within that range since more than 99% of the blades are between 62 and 63.

1.67 Cpk is equivalent to the much vaunted "5 sigma" level of statistical significance, meaning there is a 99.99994% chance Nathan's blades will be within his target range.
 
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Nathan the Machinist said:
I have processed some of that cool old vintage Micarta brand International Paper phenolic into some sheets for this and we're going to be running some scales. Rather than get our regular natural micarta (which is Accurate Acculam) try this stuff. IP had just bought the brand from Westinghouse and this was made in batches in a press rather than pultruded. Like Westinghouse, it doesn't get fuzzy when I machine it and it sends the load meter up into a range I'd associate with aluminum. This is really good stuff, they don't make this anymore, and I bought tons of it so I can offer it to you at a really good price.
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Nathan, just to verify, this is the same stuff you were offering on the preorder, right?
 
Synov said:
To translate from nerd-speak, that means the hardness range Nathan wants is either above 61.7 or below 63.3 but he's well within that range since more than 99% of the blades are between 62 and 63.

1.67 Cpk is equivalent to the much vaunted "5 sigma" level of statistical significance, meaning there is a 99.99994% chance Nathan's blades will be within his target range.
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Where do y’all go to learn all this stuff? I’m a chemist specialized in organic chemistry and had to take graduate material/inorganic chem classes but we never discussed any of this stuff.
Does anyone have any good references or books they suggest to learn about this subject matter ?

Thank you all for your time!
 
Tools_and_Tights said:
Where do y’all go to learn all this stuff? I’m a chemist specialized in organic chemistry and had to take graduate material/inorganic chem classes but we never discussed any of this stuff.
Does anyone have any good references or books they suggest to learn about this subject matter ?

Thank you all for your time!
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This is a business school thing in manufacturing or engineering. I love Nathan even more now that I know CPK was chosen because it's the abbreviation for Process Capability Index.
 
Statistics
Tools_and_Tights said:
Where do y’all go to learn all this stuff? I’m a chemist specialized in organic chemistry and had to take graduate material/inorganic chem classes but we never discussed any of this stuff.
Does anyone have any good references or books they suggest to learn about this subject matter ?

Thank you all for your time!
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Process capability index - Wikipedia

en.wikipedia.org en.wikipedia.org

When you look at the introduction section you can see that Cpk = the distance between the mean and the closest target bound, divided by 3*SD. So when Cpk = 1.67, that means the distance between the mean and the closest target bound = 1.67*3*SD = 5*SD, aka 5 sigma.
 
Nathan the Machinist said:
Our next sale will be Friday June 21st

40 Basic 5 in Magnacut. HRC 62.5 (SD .16, CPK 1.67, this batch looks really good, no sign of trouble)

If you like Magnacut or have been wanting to try it out, this is going to be a good batch for you.

Also:
I have processed some of that cool old vintage Micarta brand International Paper phenolic into some sheets for this and we're going to be running some scales. Rather than get our regular natural micarta (which is Accurate Acculam) try this stuff. IP had just bought the brand from Westinghouse and this was made in batches in a press rather than pultruded. Like Westinghouse, it doesn't get fuzzy when I machine it and it sends the load meter up into a range I'd associate with aluminum. This is really good stuff, they don't make this anymore, and I bought tons of it so I can offer it to you at a really good price.

Out in the main sale area here: https://www.bladeforums.com/forums/for-sale-fixed-blades.754/

Sale is at 3:00 eastern time.



^ Jo, Bo, Mark, Ben, Carl, Trevor, Sadie, Tanto and I hope to see you there.
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Will the next Basic 5 sale (July 5,12?) also be Magnacut or will it be Delta 3V?
 
Our next sale will be Friday July 5th

20 Basic 5 in Magnacut. HRC 62.5 (SD .16, CPK 1.67, this batch looks really good, no sign of trouble)

If you like Magnacut or have been wanting to try it out, this is going to be a good batch for you.

Also:
I have processed some of that cool old vintage Micarta brand International Paper phenolic into some sheets for this and we're going to be running some scales. Rather than get our regular natural micarta (which is Accurate Acculam) try this stuff. IP had just bought the brand from Westinghouse and this was made in batches in a press rather than pultruded. Like Westinghouse, it doesn't get fuzzy when I machine it and it sends the load meter up into a range I'd associate with aluminum. This is really good stuff, they don't make this anymore, and I bought tons of it so I can offer it to you at a really good price.

Out in the main sale area here: https://www.bladeforums.com/forums/for-sale-fixed-blades.754/

Sale is at 3:00 eastern time.



I'd hoped to also have some in D3V available for this sale but we're about out of those and I need to hold on to the remaining inventory until the pre-order is fulfilled.



^ Jo, Bo, Mark, Ben, Carl, Trevor, Sadie, Tanto and I hope to see you there.
 
Nathan the Machinist said:
Our next sale will be Friday July 5th

20 Basic 5 in Magnacut. HRC 62.5 (SD .16, CPK 1.67, this batch looks really good, no sign of trouble)

If you like Magnacut or have been wanting to try it out, this is going to be a good batch for you.

Also:
I have processed some of that cool old vintage Micarta brand International Paper phenolic into some sheets for this and we're going to be running some scales. Rather than get our regular natural micarta (which is Accurate Acculam) try this stuff. IP had just bought the brand from Westinghouse and this was made in batches in a press rather than pultruded. Like Westinghouse, it doesn't get fuzzy when I machine it and it sends the load meter up into a range I'd associate with aluminum. This is really good stuff, they don't make this anymore, and I bought tons of it so I can offer it to you at a really good price.

Out in the main sale area here: https://www.bladeforums.com/forums/for-sale-fixed-blades.754/

Sale is at 3:00 eastern time.



I'd hoped to also have some in D3V available for this sale but we're about out of those and I need to hold on to the remaining inventory until the pre-order is fulfilled.



^ Jo, Bo, Mark, Ben, Carl, Trevor, Sadie, Tanto and I hope to see you there.
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👍👊
 
Nathan the Machinist said:
Our next sale will be Friday July 5th

20 Basic 5 in Magnacut. HRC 62.5 (SD .16, CPK 1.67, this batch looks really good, no sign of trouble)

If you like Magnacut or have been wanting to try it out, this is going to be a good batch for you.

Also:
I have processed some of that cool old vintage Micarta brand International Paper phenolic into some sheets for this and we're going to be running some scales. Rather than get our regular natural micarta (which is Accurate Acculam) try this stuff. IP had just bought the brand from Westinghouse and this was made in batches in a press rather than pultruded. Like Westinghouse, it doesn't get fuzzy when I machine it and it sends the load meter up into a range I'd associate with aluminum. This is really good stuff, they don't make this anymore, and I bought tons of it so I can offer it to you at a really good price.

Out in the main sale area here: https://www.bladeforums.com/forums/for-sale-fixed-blades.754/

Sale is at 3:00 eastern time.



I'd hoped to also have some in D3V available for this sale but we're about out of those and I need to hold on to the remaining inventory until the pre-order is fulfilled.



^ Jo, Bo, Mark, Ben, Carl, Trevor, Sadie, Tanto and I hope to see you there.
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I watched your video on YouTube comparing the industry standard magnacut to your optimized magnacut (along with blades from other makers). Has there been any changes made to your current protocol for magnacut compared to the CPK magnacut shown in that comparison video?
I’m asking because, in that video, it seemed like you were still trying to optimize the magnacut even further. Will there be a point where it becomes Delta Magnacut similarly to the way 3V became Delta 3V? 🤓
Thank you for your time
 
Tools_and_Tights said:
I watched your video on YouTube comparing the industry standard magnacut to your optimized magnacut (along with blades from other makers). Has there been any changes made to your current protocol for magnacut compared to the CPK magnacut shown in that comparison video?
I’m asking because, in that video, it seemed like you were still trying to optimize the magnacut even further. Will there be a point where it becomes Delta Magnacut similarly to the way 3V became Delta 3V? 🤓
Thank you for your time
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20240626_152709.jpg

20240626_152718.jpg
 
We have continued to tweak the protocol and have it dialed in very well. I believe we have the best heat treat in the industry. This is my Magna cut at HRC 62.5. Is it as tough and durable as Delta 3V? Of course not. But it tolerates abuse and rough use, up to a certain point, and holds an edge very well.

The Delta protocol 3V was so named because the protocol deviated from the industry standard by enough that it really needed a new name. Magnacut started out as a low temperature tweak from the manufacturer. My protocol is different and optimized and measurably better, but the difference in approach to heat treat is not enough to justify a new name.
 
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