Why D2

[Mo2]

The HDFK marked D2 is PSF27

PSF27 is D2

The EDC I've made that are marked D2 are Crucible D2, but the non-particle metallurgy version. CPM D2 carbide is small and rounded and does not enhance edge retention or create a toothy edge like conventional D2, and it is a little more "mushy" and does not respond well to pre-quenching so overall it does not have the edge stability potential (given an optimized HT) or edge retention of their regular D2 though I expect it is very good in tool and die.

D2 can be cheapass Chinese import with impurities, alloy banding and mixed microstructure (this is frequently sold as American D2 because it was cutup and ground here)

It can be high end cross rolled very clean electroslag remelt

It can be spray formed to reduce issues with aggregating alloy and carbide (PSF27) this actually has some advantages over CPM

It can be one of the foreign equivalents with tungsten replacing vanadium and some Chinese maker is calling it D2




edit to add:

The amount of vanadium can vary widely from maker to maker and this greatly effects pre-quenching response. You might find a higher chrome lower vanadium and moly blend that works great in tool and die or reacts well to induction hardening that doesn't play well in a knife edge or increased carbon versions tweaked for drawing dies rather than stamping tools or a lower carbon made to use for injection molding abrasive corrosive plastics like PVC. Some D2 has no manganese and added moly and has a better secondary hardening response and reduced pitting and is used to extrude vinyl siding. D2 is like hotdogs with many makers using different ingredients. Many flavors.

PSF27 is D2


D2 might be my personal favorite steel but I don't use it much because other people value other properties differently than I do and there isn't much demand for it. Also, it was frustrating having one batch behave differently than the next. 3V does so much of what D2 does and does it with much better toughness, and better corrosion resistance and edge stability too that I work in 3V almost exclusively now, and from a manufacturing point of view it is wonderful ordering 3V custom rolled and getting an entire ingot of it with consistent chemistry and microstructure. People tend to think of me as a 3V guy, but I was a D2 person first.

And another for good measure ^
https://www.bladeforums.com/threads/is-it-psf27-or-d2.1597897/#post-18249001

 

[Xero Xero]

https://www.hudsontoolsteel.com/technical-data/steelD2

Here's a link to a site that provides data regarding D2.
Charts and graphs along with some technical discussion. Lots of quality knife production uses D2 for a variety of reasons. The discussion here -- forgive the analogy -- seems very much like discussing the relative merits of blondes, brunettes, red-heads. LMAO

 

[leghog]

Why are the knife companies from China all using D2 steel?
I’m to the point I will not buy a knife if it has D2 steel. I don’t trust the chinesiam steel from that country.

You're missing out on some good knives. My L.T. Wright NextGen in D2 with iron wood scales is an excellent Kephart inspired knife. Holds a great edge and easily sharpened. I like 1095, but D2 has better rust resistance even though it too is high carbon.

 

[22-rimfire]

I have to admit that I'm a little suspicious of the heat treat and actual steel used by the entry level Chinese manufacturers. But Chinese manufacturers like ones in Japan, Taiwan and so forth will improve as long as there's a demand for their product which there is. 15 years from now, few will question that a Chinese made knife is substandard as compared to Japan and Taiwan stuff now. China is filling the mass manufacturing vacuum right now. This will change.

 

[Blacplastik]

I don't know about all them other knives but I was surprised at how good the D2 in my Rat 1 is. The only example of D2 that I have tried. Meaning it reminds me of High Carbon in the way it sharpened and felt cutting challenging materials (hard rubber etc.). It held the edge LONGER than good High Carbon would have.
Good stuff !

I'm not all about it, in theory, because it isn't powder / high tech (fine grained) but danged if it didn't make me sit up and take notice.
No complaints from me.

Rat 1 is made in Taiwan. I have one also and it’s a great knife

 

[John_0917]

1) D2 has long been in the public domain as far as formula and there are ranges on some of the elements

2) It’s made using the conventional ingot process and the manufacturing is fairly simple as far as steel making hoes.

3) It’s air or oil hardened and does not need to be Cryo treated so that’s simple as well.

4) It doesn’t contain any exotic elements like niobium or tungsten that are harder and more expensive to obtain and machine.

 

[Halfneck]

I like D2 (and CTS-XHP) in knives. First used it in a knife from Bob Dozier, then one from Tom Krein. Of course I realize the D2 in my Steel Will Modus may not be as good as that in my custom D2 knives. That said, for the price, I like it a lot better than the various CR steels I've used in other inexpensive knives.

 

[Xero Xero]

I like D2 (and CTS-XHP) in knives. First used it in a knife from Bob Dozier, then one from Tom Krein. Of course I realize the D2 in my Steel Will Modus may not be as good as that in my custom D2 knives. That said, for the price, I like it a lot better than the various CR steels I've used in other inexpensive knives.

I bought a Schrade Uncle Henry Skinner (UH 2203 I believe) -- stag grip, drop point 1.25" thick D2 blade. This knife lists on the Schrade site for $119.00. I got it from SMKT as a "special" for less than $50. Schrade has a long standing reputation for quality product, and this knife is a jewel. -- Oh yeah, it's mfg'd in China but no where on the knife does "China" appear. Serial number and limited lifetime warranty, both good signs.

Here's a good discussion on D2
https://www.knivesillustrated.com/articles/does-d2-tool-steel-make-a-good-knife/

 

[fjblair]

Any companies using D2, chinese or not, I think have learned that if they want to sell an inexpensive knife and have it sell well thats the way to go. People aren’t as accepting of cheap steels as they used to be. Make a rat in aus 8, it sells but use D2 and everyone flocks to it. Ive never had a problem with D2 from any company.

D2 is used in not inexpensive knives made by some premium knifemakers. As others have mentioned, it can be an excellent steel.

 

[warden41272]

I realize I'm probably necro-threading this, but I thought I'd throw my $.02 in. D2 is one of my favorite steels. It's an aggressive cutter. But I certainly notice differences in makers. My Bestech seems to be fantastic, while an Eafengrow I picked up on a whim (because I liked the handle and blade shape) is cheap kitchen knife soft. I can get my Bestech to an edge that will literally pass a HHT, while the Eafengrow is suitable only for scraping cotton picker spindles. I have a Katsu in D2 that works very well, too. As has been said before, D2 takes a lousy edge and holds it forever.

 

[Mo2]

I realize I'm probably necro-threading this, but I thought I'd throw my $.02 in. D2 is one of my favorite steels. It's an aggressive cutter. But I certainly notice differences in makers. My Bestech seems to be fantastic, while an Eafengrow I picked up on a whim (because I liked the handle and blade shape) is cheap kitchen knife soft. I can get my Bestech to an edge that will literally pass a HHT, while the Eafengrow is suitable only for scraping cotton picker spindles. I have a Katsu in D2 that works very well, too. As has been said before, D2 takes a lousy edge and holds it forever.

Eafengrow are scammers and cloners. That steel is likely not d2. In fact I've heard people test the steel showing it to not be d2 at all. If I had the links id post them but I can't remember where I found it. In any case avoid that company if you can even call it a company due to the practices they do. Ultimately they ride on other people's backs to make money.

 

[jason41987]

I found some people having done some tests on the so-called D2 used in a Chinese made knife and the results were that the Chinese D2 was good, maybe even better than American, harder too. Why D2? Why not? When you compare 1/8" or 3/16" 1" wide blade stock prices between basically any steel from cheap 420 and 1095 up to 154CM and SV35 it's only something like $10-$15 price difference from low end to the top per blade, D2 being on the lower end of that scale being even closer in price to something like 8cr.

So with minimal differences in material costs you have to ask yourself, why not D2? And I think the reason you don't find a lot of budget D2 options from people like Spyderco, Kershaw, etc is because they all have premium line knives they'd rather you purchased. Why give you something sufficient enough for your needs if they can make you pay $150 to get something somewhat decent? It's probably why a company like Ontario which doesn't really have this high end knife line decided to put it into their Rat 1 and 2, because, why not? Spyderco could EASILY afford to sell D2 Tenacious' but less people would buy PM2s then.

Counterfeits using another companies logos and trying to pass them off as legitimate will likely lie about the steel too, but a number of them not doing this (take the Cutjacks for example) do not.

 

[vwb563]

Nothing wrong with D2 if it's really D2. It's a very tough semi-stainless steel. The "D" in D2 stands for "die" steel that's used in manufacturing to cut other steels. Any steel that's used to cut other steels has to be tuff stuff. I think that's why Medford uses it because of it's toughness. It also holds a great edge and is reasonably easy to sharpen. It's only real drawback is it's not truly a stainless steel generally having only 12 percent chromium. It behaves like a carbon steel when sharpening but does have enough chromium to resist rusting. As long as you apply a small amount of oil coating every now and then it will stay rust free just like any other stainless steel. It's really good stuff...

 

[whp]

"chinesiam"... cute. Got a question and xenophobic slap in all at the same time.

If you don't trust a company, don't buy their product no matter what you think they might be doing in their manufacture or use of materials. That is your right and only makes good sense.

There will no doubt be those that will gladly pile on here to tell you they "know" that Chinese makers aren't using D2. No testing, no smoking gun, no manufacturer's purchasing receipts, needed. They can tell what steel is being used by holding a knife (maybe any knife!) and determine its authenticity. They know the real truth from osmosis and by reading the internet.

I have no doubt that as with all products, including products we know and trust, there are issues of bait and switch. So as with all products, only buy brands from people you trust. I believe that the verified vendors on BF most likely take the time to make sure they aren't cheating customers. I don't think they would knowingly sell a phony product, and plenty of them sell knives with D2 blades.

You should read a bit more on D2. https://goo.gl/UQx4VU

Although mine and many others favor this steel as a reliable hard worker, you can see that it is far from meeting the needs of today's "super steel" crowd, and is in fact, an old steel developed decades ago as a tool steel. At this time, it is manufactured all over the planet and the price is inexpensive. A quick look shows (less shipping) that it can be purchased for about $250 to $300 a ton.

So, on this rainy day in my town:

One ton of D2 at $275 per ton + $50 a ton shipping = $325 per ton cost.
2000 pounds X 16 = 32,000 ounces, or .01 per ounce. One cent.
So if an average 6 ounce folder is 1/2 blade, that would mean a 3 oz blade.
So raw material cost per blade would be about 3 cents.

Do you really think anyone would counterfeit such a dirt cheap, readily available steel? They could I guess, but doubtful any manufacturer of any repute would find that a worthwhile effort.

Robert

If these numbers are right, how can anybody believe that there would be fake D2 steel blades?
Is somebody giving away the fake steel? At 3 cents for the D2 blade material, how much money is made with a substitution?
Either these numbers are wrong or the accusations about fake D2 are wrong.

 

[PirateSeulb]

I would suspect those prices by weight of D2 are probably what it cost a company who turns the D2 into various sized stock and that company then charges for their cost to process and store the material plus a profit causing it to rise dramatically on a price/ounce. To know how "profitable" a fake D2 would be we would need to know how much less other steels like 440A cost in such volume.

 

[SteelJunkee]

The only reason someone would substitute D2 for another same priced steel is because they can't get it done right and for the price you pay and the performance it offers I consider it a super steel. I don't have any experience with D2 folders but I have tried a bunch of fixed blades, I have 2 at the moment and it was never a deceiving experience. The toughness and hardness of that stuff is beyond anything else in that range of price. Good D2 Vacuum hardened at 60-62HRC makes incredible blades.

 

[Mo2]

The only reason someone would substitute D2 for another same priced steel is because they can't get it done right and for the price you pay and the performance it offers I consider it a super steel. I don't have any experience with D2 folders but I have tried a bunch of fixed blades, I have 2 at the moment and it was never a deceiving experience. The toughness and hardness of that stuff is beyond anything else in that range of price. Good D2 Vacuum hardened at 60-62HRC makes incredible blades.

The reason why some companies say one steel but use another is because no one buying it will tell the difference and it's cheaper. That and it's popular so they put what's popular on the blade. Popular sells. Especially in this market of trends.

Trends suck because there's more to just the steel composition but most buyers don't know this.

Viper knives is known for selling real m390 but the heat treatment is always lacking. Why use it if it's not a good ht? Cause 'm390' sells.

 

[dirc]

Nothing wrong with D2 if it's really D2. It's a very tough semi-stainless steel. The "D" in D2 stands for "die" steel that's used in manufacturing to cut other steels. Any steel that's used to cut other steels has to be tuff stuff. I think that's why Medford uses it because of it's toughness. It also holds a great edge and is reasonably easy to sharpen. It's only real drawback is it's not truly a stainless steel generally having only 12 percent chromium. It behaves like a carbon steel when sharpening but does have enough chromium to resist rusting. As long as you apply a small amount of oil coating every now and then it will stay rust free just like any other stainless steel. It's really good stuff...

Actually, even good (genuine) D2 is NOT very tough. It's actually one of the weakest steels in terms of toughness. What it is good at is edge retention, which is very different.
I would NOT use D2 in any sort of bushcraft scenario.

Crucible put out a decent review of hardness and toughness levels for their cpm-3v steel, which includes D2. Look at this:

http://www.crucibleservice.com/eselector/general/generalpart1.html

 

[WillB]

Actually, even good (genuine) D2 is NOT very tough. It's actually one of the weakest steels in terms of toughness. What it is good at is edge retention, which is very different.
I would NOT use D2 in any sort of bushcraft scenario.

That seems overly generalized. Has anyone who has used a good D2 knife designed for bushcraft here ever had one fail? Seems makers and uses choose D2 for that all the time, and they appear to hold up very well. Does it not come down to the balance of hardness developed by the HT?

 

[vwb563]

That seems overly generalized. Has anyone who has used a good D2 knife designed for bushcraft here ever had one fail? Seems makers and uses choose D2 for that all the time, and they appear to hold up very well. Does it not come down to the balance of hardness developed by the HT?

Exactly. Ka-Bar used it their D2 Extreme survival fixed blade with great success. If it had been a weak steel they would not have used it in a knife that's destined to be used and abused. D2 is a good all around steel and nothing is going to convince me otherwise.