Alloy banding in A2?

james terrio said:
Me too. Life is just too short to muck about with mill scale and weird sizes and whatnot.

Whenever possible I get my stock from Aldo (NJSB) and pay him a little extra to surface-grind it. Chuck (AKS) often has nicely ground stock as well. Works for me. I don't know if that's precise enough for your purposes, you'd have to talk to them about that.
Click to expand...

Cool, thanks for the info! I'll have a look into that!

A difference in thickness of like 0.010" is really not a big deal for me given that I'm making fixed blades, but anything too much over that and I think it could start causing issues. Deal with scale and decarb from rolling is definitely something I want to avoid too!
 
aarongough said:
The $640 price I gave was from the NSM website, for belt-ground and saw cut .186x6x36" which was the closest sheet size I could find to what I normally use.

The price you quoted is not shown on their website anywhere as far as I can see. Was that a 'full sheet' price?

For me having the stock come precision ground is a real plus as I don't want to be dealing with stock of different thicknesses, and flat grinding on the grinder is very inefficient compared to paying the supplier to do it. I really wish NSM would do precision grinding, rather than their belt grinding.
Click to expand...

The prices are for shear cut. The small deformation at the sheared edge isn't bad because of the hardness of the sheet. The 24"x36" piece requires emailing them for a quote.
 
Interference Fit Co. said:
The prices are for shear cut. The small deformation at the sheared edge isn't bad because of the hardness of the sheet. The 24"x36" piece requires emailing them for a quote.
Click to expand...

Ok thanks! I'll make sure to talk to the guys at NSM again to see what the prices are for larger sheets like the size you mention!
 
aarongough said:
Ok thanks! I'll make sure to talk to the guys at NSM again to see what the prices are for larger sheets like the size you mention!
Click to expand...

Just FYI, when I ordered my sheet last month I was told they were going to have a price increase at the beginning of this month. Based on how much the other sizes changed in price, I'm expecting you'd get a quote for around $800 for the piece I paid $700 for last month.
 
I just had a thought:

In my last batch (which were all satin finished) I didn't notice any banding. None. It took me a while to think back and look through my emails and work out which brand of steel I was using. The steel from that batch came from Precision Marshall. I had decided to avoid them in the future because their surface grinding wasn't as clean as the Starret stock I'd used, but the steel itself seemed really good.

I'll probably look at getting some more stock from them I guess! I'm also going to talk to Buffalo Precision. Apparently they're owned by Uddeholm and sell a broad range of precision ground stock which is made by Uddeholm, so they'll probably be a good option.

I had made the mistake in the past of assuming that because there was a standard for the composition of A2 that it would all roughly be equal. Clearly that's not true. If I find a company that consistently turns out clean A2 I will make sure to update this thread. I'm sure the either Uddeholm or Precision Marshall will be able to fill that role!
 
Ok guys, another follow-up:

Just had a chat with a metallurgist working for Precision Marshsall. He said that there's no guarantee that A2 won't have banding, and that because it doesn't affect the performance of the steel they wouldn't consider it to be a defect. That realistically means that they won't replace steel bought from them just because it exhibits banding (as far as I understand).

He said that he hasn't seen much banding in A2, that it would generally be seen more in higher alloy grades like D2 or S7.

He suggested that I look at procuring steel from a mill that uses the ESR (electro-slag remelting) process as it's likely to exhibit less banding.

I'm currently waiting on a quote from Uddeholm here in Canada for 5/32" thick flat ground stock. Unfortunately that seems to be the one fractional size that they don't keep as a stock item.

I'm also going to start chasing up some pricing on sheets of 3V.
 
Aaron, check out 4v, too. It's possibly a better fit for your intended knives. Sorry to hear about all these frustrations for you, too - you poured a lot of time and energy into your selection. Sucks that something this goofy could rear it's head...
 
Matthew Gregory said:
Aaron, check out 4v, too. It's possibly a better fit for your intended knives. Sorry to hear about all these frustrations for you, too - you poured a lot of time and energy into your selection. Sucks that something this goofy could rear it's head...
Click to expand...

Thanks mate, that's appreciated. Definitely a bummer to find out about this sort of problem at this stage. Will have a look at 4V too.

I've asked the metallurgists at Uddeholm the same question as I asked Precision Marshall, ie: do they consider carbide segregation/banding in their steel to be a defect... Uddeholm is well known for their extremely clean steel so I'll be curious to see how they answer that.
 
james terrio said:
Let me know what you find in that regard. I'll be happy to share my sources with you as well.
Click to expand...

Will do. Got a quote back from Uddeholm today for a custom precision-ground sheet: 5/32x6x36" = $149

I was pretty surprised by that price actually. As I noted above this is not the pricing for a stock item, this is a custom cut and grind, and it's still less expensive than Starrett, and it's straight from Uddeholm! Thought that was pretty great!

I'm still waiting to hear back from their metallurgists regarding whether they regard banding/segregation as a manufacturing defect. If they do, and they'll guarantee that I get clean steel then I'll be switching over to them as my sole supplier.

I'm also waiting on a quote for some precision ground Vanadis 4 Extra...
 
It's the amount of banding not whether or not it's there ! Chemical composition is a big factor as is processing. Maybe you should compare European or American to Chinese LOL
 
mete said:
It's the amount of banding not whether or not it's there ! Chemical composition is a big factor as is processing. Maybe you should compare European or American to Chinese LOL
Click to expand...

Right, I should clarify my statement: any amount of visible banding.

Not sure if that's an unrealistic expectation or not, but realistically that's what I (or any of us) need in order to make quality knives. If's that's not possible with a traditionally melted steel then I'll have to switch over to a powder steel.

And yes, I'm sure that chinese made steel is a very different animal compared to US or European steel, hence why I'm looking at sourcing from Uddeholm, given that they're known for how clean their steel is.
 
Some thoughts after reading this thread...

The Starrett name isn't what it used to be. Speaking from personal experience, the Starrett calipers in my shop are not very good (unreliable accuracy) and the Starrett bandsaw blades had either poor quality steel or HT because they all developed lots of cracks and broke quickly where the less expensive Lenox equivalent last for months.

A2 will always have some banding, but it shouldn't be pronounced like that. It's usually very thin and short.

Uddeholm is a good steel producer making quality steel but I don't believe there is anything special about their A2. I believe it can often be found in some of the less expensive import grade A2 offerings. Personally I have had good luck using American made A2 manufactured by Latrobe.

I have used 3V as a good substitute for A2. They're both very durable and they both have pretty good edge retention. 3V is more durable, has better edge retention and has better corrosion resistance. The only thing I can think of where A2 is better is that A2 is a little easier to process and is about 1/3rd the cost.

There is a certain mystique surrounding 3V, and it certainly is a very durable steel, but I don't think it holds an edge as well as properly done D2.

These guys have a high end remelt A2 http://sb-specialty-metals.com/products/premiumproducts

I have found that every dollar I spend on quality is re payed when I sell.
 
Nathan the Machinist said:
Some thoughts after reading this thread...

The Starrett name isn't what it used to be. Speaking from personal experience, the Starrett calipers in my shop are not very good (unreliable accuracy) and the Starrett bandsaw blades had either poor quality steel or HT because they all developed lots of cracks and broke quickly where the less expensive Lenox equivalent last for months.

A2 will always have some banding, but it shouldn't be pronounced like that. It's usually very thin and short.

Uddeholm is a good steel producer making quality steel but I don't believe there is anything special about their A2. I believe it can often be found in some of the less expensive import grade A2 offerings. Personally I have had good luck using American made A2 manufactured by Latrobe.

I have used 3V as a good substitute for A2. They're both very durable and they both have pretty good edge retention. 3V is more durable, has better edge retention and has better corrosion resistance. The only thing I can think of where A2 is better is that A2 is a little easier to process and is about 1/3rd the cost.

There is a certain mystique surrounding 3V, and it certainly is a very durable steel, but I don't think it holds an edge as well as properly done D2.

These guys have a high end remelt A2 http://sb-specialty-metals.com/products/premiumproducts

I have found that every dollar I spend on quality is re payed when I sell.
Click to expand...

Thanks for the input Nathan! Do you know who sells flat stock made from Latrobe steel? I would be interested in following that up.

I do also quite like 3V, but there are a few things I'm not a fan of with it too:

1) I haven't found a source for precision ground flat stock. If anyone can has a place that supplies 3V in precision ground sheets I would love to hear about it!
2) The datasheets for many of the Crucible grades (including 3V) are pretty sparse compared to what you get for an Uddeholm steel. I want the full CCT graphs and so on for the steel that I'm using so that I can tweak my HT with confidence. I'm aware that I can tweak the HT for 3V even without that data, but I would feel less confident about what I'm doing.

I really don't think that right now is the right time for me to be changing steels if I can help it. I have a bunch of experience working with A2, and I'm right in the middle of working on a big batch of customer orders. I have a lot of confidence in my abilities with A2, but not so much with the other steels as I haven't had the time to test them fully.
 
Nathan the Machinist said:
There is a certain mystique surrounding 3V, and it certainly is a very durable steel, but I don't think it holds an edge as well as properly done D2.
Click to expand...


I agree, Nathan. The primary advantage is the tremendous increase in toughness, which in my experience is noteworthy. If the knife is going to see any kind of abuse, 3v makes the most sense. Although I have little love for D2 in most circumstances, it's kind of freakish how well the toothy carbides it has work on cleaning game.

Aaron, I can't help but thinking you're right about finding a good source for A2 and scarfing up a ton of it. Go with what you know!!!!
 
Matthew Gregory said:
I agree, Nathan. The primary advantage is the tremendous increase in toughness, which in my experience is noteworthy. If the knife is going to see any kind of abuse, 3v makes the most sense. Although I have little love for D2 in most circumstances, it's kind of freakish how well the toothy carbides it has work on cleaning game.

Aaron, I can't help but thinking you're right about finding a good source for A2 and scarfing up a ton of it. Go with what you know!!!!
Click to expand...

Yeah in the short term at least that's the plan. I'll likely investigate new steels soon, but I'd like to do that at my leisure rather than under a massive time pressure!

Talking to Uddeholm here and finding out that ordering custom sheets is not expensive opens up a whole new world of steel for me, so I'm excited to test a bunch of stuff out! But only after I've managed to get through my back-orders, then I can stop and have fun!
 
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!
 
What an encouraging thread this has turned out to be. It's my belief that any maker who focuses on great geometry and seeks out a good alloy to work with, learn about, and maximize for performance is going to have a lot of happy clients :)

Thanks, guys :thumbup:
 
james terrio said:
What an encouraging thread this has turned out to be. It's my belief that any maker who focuses on great geometry and seeks out a good alloy to work with, learn about, and maximize for performance is going to have a lot of happy clients :)

Thanks, guys :thumbup:
Click to expand...


Couldn't agree more James!
 
I was having a look back at the results of the steel testing I did a while ago: http://www.bladeforums.com/forums/s...teel-testing-underway?p=12708211#post12708211

I noticed that the steel that did the best in the chip resistance test was actually CPM154, it fell back in the overall rankings because of it's failure in the tip strength test... I still have the original test blades, when I get to the shop later on today I'm going to measure the tips on the test pieces to see if they were all close in dimensions, that's one aspect that probably wasn't the most tightly controlled in the original testing...

Any of you guys have experience with CPM154 in hard-use knives?
 
You must log in or register to reply here.
Back
Top