Alloy banding in A2?

aarongough said:
As another follow-up:

Just had a chat with Jeff at Niagara Specialty Metals (NSM). I didn't realize from talking with them in the past that they also have the capability to supply precision ground flat stock in the size I generally use (6x36").

They can also supply US made A2 (sourced from Latrobe, Crucible or Carpenter generally from what they said).

I have quotes coming back from them for 5/32x6x36" surface ground flat bar in CPM3V, CPM4V and A2.

Seems that this problem with the A2 I was using might be a blessing in disguise, I'm finding out that a lot more steel is easily accessible to me than I previously thought. I guess it also helps that I'm looking at buying much larger pieces than I would have in the past!
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Glad you got good news from NSM. When I purchased my 3V sheet, I also purchased some precision ground S110V. I've been surprised at their selection. Most of the sizes and materials you are having quoted are listed in their online sales page too (though not the S110v) . Online Store

Good luck with some hard decisions on steel.
 
So I went back to the shop this afternoon and looked at my old test sample blades made from CPM154. Here's the results:

dGS8DEzl.jpg


Seems that the tip on the CPM154 test blade was a fair bit thinner than the other blades. This is a silly oversight, something I should have caught when I was doing the testing. If I adjust the results to assume that steel passed the tip strength test then it's overall score is basically identical to CPM3V and A2. I find that really interesting because I had originally hoped to use a stainless steel for my knives, but I discounted CPM154 because of my testing.

I'll be putting together some test knives in CPM154 in the near future to do more testing.

Now, onto steel sourcing. I have been talking to Niagara Specialty Metals and Bohler/Uddeholm quite a bit. Here's what I've heard back so far:

Uddeholm - 5/32x6x36 precision ground A2 flat stock: $149.92 (3 day lead time)
NSM - 5/32x6x36 surface ground CPM3V flat stock: $569 (1 week lead time)
NSM - 5/32x6x36 surface ground CPM4V flat stock: $589 (1 week lead time)
NSM - 5/32x6x36 surface ground CPM154 flat stock: $589 (1 week leadt time)
NSM - 5/32x6x36 surface ground A2 flat stock: $503 (7-8 weeks lead time)

Bohler/Uddeholm apparently cannot supply Vanadis 4 Extra for me in a suitable size, apparently the mill doesn't normally roll as thin as I'd require so the cost of getting them to do so would be prohibitive. I've asked them to get me a full list of the steels they can supply in 5/32" flat ground stock, will keep you guys posted on that front.

If anyone has other good sources for CPM3V or CPM154 flat stock please let me know!

I'd actually be quite excited about the idea of offering my knives in CPM154 if it was possible. My original design was for the blade to be stainless as I wanted to keep the knife as low-maintenance as possible.

Interesting how this whole thing has turned out so far!
 
aarongough said:
I'll be putting together some test knives in CPM154 in the near future to do more testing.
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It's certainly worthwhile to try it out with your designs and geometry. CPM-154 is quite popular, and in my experience it's tougher than people give it credit for.
 
JamesPEmmons said:
Arron nice talking with you this weekend. Looking forward to seeing the videos and photos you took.

Here is a full sheet of CPM154 for much less https://www.knifemaker.ca/product.php?productid=16965&cat=250&page=1

James
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Nice to meet you too James! I'll be doing a rough cut of the video tonight hopefully.

Thanks for the link! Do you know what finish is on that sheet? Mill finish, rough belt ground or something else?

james terrio said:
It's certainly worthwhile to try it out with your designs and geometry. CPM-154 is quite popular, and in my experience it's tougher than people give it credit for.
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I will admit I was quite surprised when I had a look at it last night. Even after plenty of steel-on-steel contact from my trusty crowbar I was only able to get the edge to roll or dent, it wasn't chipping at all which is pretty impressive. And this is CPM154 hardened to 61.5HRC!

I have 2 bars of it at the shop so I'm looking forward to putting together some more test blades.

Funny how it's come full circle like that given that CPM154 was really the steel I was hoping to use right at the beginning!
 
aarongough said:
That sheet I asked for a quote on is precision ground to a tolerance of +- 0.002", rather than their usual belt finish, which accounts for the difference in price
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Yup, I bet that's it. :)

I'm curious if he was able to tell you the thickness tolerance on the normal belt finish? I was going to go this route on the next run, but if the tolerance is too large I may contact a couple local machine building companies and get a quote on surface grinding a 2'x3' sheet.

Thanks for sharing the results of your steel search.
 
Interference Fit Co. said:
Yup, I bet that's it. :)

I'm curious if he was able to tell you the thickness tolerance on the normal belt finish? I was going to go this route on the next run, but if the tolerance is too large I may contact a couple local machine building companies and get a quote on surface grinding a 2'x3' sheet.

Thanks for sharing the results of your steel search.
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They call their normal belt finish the 'timesaver finish' apparently. They said it's +- 0.010" or so. They said their surface ground finish will be much smoother also than the belt ground in addition to being tighter tolerance.
 
I would need quite a bit of convincing before paying that much extra for precision grinding. I just don't see .002" tolerance being necessary for fixed blades... even at .010" "off" you're going to grind most of it away anyhow, all you might need to do is true up the tang (and that's going to take seconds per blade, not minutes). The biggest reason I like "plain" surface ground steel is to get rid of the dang mill scale; that pays for itself in the time and belts I save.
 
james terrio said:
I would need quite a bit of convincing before paying that much extra for precision grinding. I just don't see .002" tolerance being necessary for fixed blades... even at .010" "off" you're going to grind most of it away anyhow, all you might need to do is true up the tang (and that's going to take seconds per blade, not minutes). The biggest reason I like "plain" surface ground steel is to get rid of the dang mill scale; that pays for itself in the time and belts I save.
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Yeah I hear you!

I'm trying to get a proper quote on the same steels with both mill finish and 'timesaver' belt ground finish... The reason being that their price for *belt ground* CPM3V .186x6x36 on their website is higher than what they quoted me for surface ground, so I'm sure that must be incorrect.

The link that James posted above at knifemaker.ca for 5/32x6x36 CPM154 for $284 is worlds different from what's on the NSM-NY website, so I'm trying to chase that up too.
 
I also had a proper chat with one of the external sales reps at Bohler/Uddeholm Canada's main office. He's going to chase up availability and pricing for me on a bunch of interesting steels including M390, K890, Vanadis 4 Extra and others at his discretion. Will report back on that too.
 
Just chatted quickly to the guys at knifemaker.ca, they have 5/32x6x36 sheets of CPM154 for $284.

Those sheets are mill finish, which is I guess what Aldo is selling as well. The NSM website doesn't even list prices for mill finish...

How hard is it to flat grind the scale off from CPM154 or CPM3V, have you guys dealt with that before? Anyone tried just pickling the scale off with vinegar or FC?
 
I can take a bar from Rob at knifemaker.ca and grind the mill scale off in about 15 seconds with a new 60 grit belt. You really are over thinking this.

Also if you really need percision ground why not buy a Surface Grinder, in our area they can be had for 500 to 1000. It best to surface the blade after HT any ways to grind out any warpage.

PS You have my card from this weekend, send me an e-mail with your number. I will call and we call discuss steel orders as I will soon be ordering a batch of stainless
 
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aarongough said:
How hard is it to flat grind the scale off from CPM154 or CPM3V, have you guys dealt with that before? Anyone tried just pickling the scale off with vinegar or FC?
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More times than I care to remember ;)

Pickle first, then grind. Use a somewhat worn coarse belt (36 or 50); it will glaze/knock the crisp edges off a new belt pretty quickly. High belt speed is your friend. Once you start seeing mostly clear raw steel, switch to a fresh 60 or 80 and finish cleaning it up. There may be some minor pitting under the scale itself, shouldn't be a major problem.

It's not difficult, it's just boring and uses up belts.
 
JamesPEmmons said:
I can take a bar from Rob at knifemaker.ca and grind the mill scale off in about 15 seconds with a new 60 grit belt.
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Ok cool, haven't tackled it before so I wasn't sure how hard it was to deal with.

JamesPEmmons said:
You really are over thinking this.
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Wouldn't be the first time :)

JamesPEmmons said:
Also if you really need percision ground why not buy a Surface Grinder, in our area they can be had for 500 to 1000. It best to surface the blade after HT any ways to grind out any warpage.
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That's something I've started to consider as I'd like to get into folders at some point. Haven't seen any that cheap round here, but will keep an eye out!
 
james terrio said:
More times than I care to remember ;)

Pickle first, then grind. Use a somewhat worn coarse belt (36 or 50); it will glaze/knock the crisp edges off a new belt pretty quickly. High belt speed is your friend. Once you start seeing mostly clear raw steel, switch to a fresh 60 or 80 and finish cleaning it up. There may be some minor pitting under the scale itself, shouldn't be a major problem.

It's not difficult, it's just boring and uses up belts.
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Thanks mate! Doesn't sound so bad.

Sounds like I've got some testing to do with CPM154!
 
Paid 450 for mine two years ago. I think I forget how to build a knife without it. I will also keep a look out for one for you.

PS why not S35VN it is a stainless 3v and only 100 buck more for a full sheet.

PSS I am just trying to add to your over think problem. :-)
 
JamesPEmmons said:
Paid 450 for mine two years ago. I think I forget how to build a knife without it. I will also keep a look out for one for you.

PS why not S35VN it is a stainless 3v and only 100 buck more for a full sheet.

PSS I am just trying to add to your over think problem. :-)
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Haha, I was just thinking that when you mentioned S35VN, "More options!?!"

I'm going to make a few blades in CPM154 (as I already have bar stock on hand) and will go from there I think. What I saw last night when I was being rather mean to that test blade really impressed me in terms of toughness. I'll carve a few spoons, prep some firewood and so on, see what I think after that.

If you were to keep an eye out for a grinder as well that would be greatly appreciated!
 
aarongough said:
They call their normal belt finish the 'timesaver finish' apparently. They said it's +- 0.010" or so. They said their surface ground finish will be much smoother also than the belt ground in addition to being tighter tolerance.
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A Timesaver is a large belt sander. Generally around 48" wide. Given that you're unlikely to have larger than a 0.001" taper in the area the size of a knife blade, I think that I'll continue to plan on that for my next sheet. Even if the sheet varies by the full tolerance, I'm not going to be concerned about the slight variations in thickness. More than likely the sheet will be within 0.002" in deviation from its average, with the +/-.010 tolerance applying to the average size VS nominal.

Good enough for me, I make each sheathed for each knife specifically anyway.
 
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