Few quotes:
From Carpenter’s webpage:
Carpenter CTS XHP Alloy
(Nominal Analysis)
1.60 C, 0.50 Mn, 0.40 Si, 16.00 Cr, 0.35 Ni, 0.80 Mo, 0.45 V, Bal. Fe
Air hardening, high carbon, high chromium, corrosion resistant alloy which can be described as either a high hardness Type 440C stainless steel or a corrosion resistant D2 tool steel. Possesses corrosion resistance equivalent to Type 440C stainless but can attain a maximum hardness of 64 HRC, approaching that of D2 tool steel. Now available in strip product form.
This proprietary alloy is in the Carpenter CTS™ family of alloys that offer superior edge retention and surface finish, an ability to be machined to a fine edge, and consistent heat-treatability from lot to lot. Consider CTS alloys for many blade applications including commercial food processing, paper processing, textile, packaging, recycling/refuse, kitchen knives, hand tools, scissors/shears, shaving razors, sport/hunting knives, ice skates, military/defense, law enforcement, salon blades and various surgical/medical applications.
From Tactical Life
http://www.tactical-life.com/online/tactical-knives/space-age-xhp-blasts-off/
Space Age XHP Blasts Off!
Written by Tactical-Life.com. Author Archive »
Veteran Carpenter Steel has entered the knife-making arena with new blade steel that Bob Dozier calls “440C stainless on steroids.”
This Dozier Personal Knife features a Wharncliff pattern blade made from Carpenter XHP stainless. Independent testing of the steel revealed that it easily out-cut many other premium blade steels, including S30V.
There’s an old tradition connected to marriage that recommends providing the bride with “something old and something new.” Well, the Carpenter Steel Company has been around for 120 years and that qualifies as “something old.” And they’ve recently introduced a blade steel alloy bearing the name CTS-XHP; that fits the designation “something new.”
Carpenter Steel is a huge facility consisting of several buildings spread over some 300 acres in Reading, Pennsylvania. The company was founded in 1889 and has been continuously producing various steel products ever since. They are a leader in the development, manufacture and distribution of cast/wrought and powder metal stainless steel and specialty alloys. At the present time, the company has 14 different types of steel designed especially for the cutlery industry.
Signature Steel
The CTS (CTS is the Carpenter trademark) XHP steel is an air-hardened, high carbon, high chromium and corrosion-resistant steel that is comparable to 440C stainless steel. The chemical formulation of the steel is as follows: Carbon 1.60%, Chromium 16.00%, Magnesium 0.50%, Molybdenum 0.80%, Nickel 0.35%, Silicon 0.40% and Vanadium 0.45%. While 440C has a similar Chromium content, the formulation only has 0.95-1.20% Carbon in its makeup.
As evidenced above, the major difference between XHP and 440C lies in the added Carbon content of XHP. The addition of both Nickel and Vanadium, which are absent in 440C, is also a component that contributes to enhanced edge retention. When compared to 440C, XHP offers superior edge durability, outstanding surface finishing and consistent heat-treatability from steel lot-to-lot.
Of course, XHP is a powder steel produced by Metal Injection Molding (MIM), a manufacturing technique we’ve covered in this column previously. Basically, the primary material is physically powdered. Afterwards, the powdered steel is passed through a die and then heat and pressure self-weld the individual particles together.
"'When compared to a new knife with an S30V blade, which cut through .5-inch manila rope at maximum of 200 times before the edge began to fail; an XHP blade with identical edge geometry was able to make 850 cuts. Obviously, the XHP blade possessed greater cutting endurance.'"
From Sal Glesser
“What's seems to be unique about the steel is that it is the first powdered stainless D2.”
From jayfisher
D2 cold work high carbon, high chromium die steel: is the highest carbon alloy tool and die steel (thus the "D" designation) typically used in knife making. It has 12% chromium so it doesn't resist corrosion as well as high chromium tool steels and will rust if continually exposed to corrosive moisture, acidic fluids (like orange juice or blood), so requires more attention. But at 1.65% carbon, it can be made very hard, and very wear resistant. The polished finish on D2 can be somewhat mottled with an orange peel appearance. This is due to chromium carbides forming in the steel during heat treat, the very thing that makes this steel so wonderful (most steels form iron carbides). Please note: some manufacturer's versions of D2 do not exhibit the orange peel granularity in the polished finish because they are made with a higher sulfur content. These high sulfur versions are easier to machine and are designated "sulfurized D2." D2 is very hard to work with, expensive, downright malicious to abrasives, resistant to cutting and milling and metal fabrication. So it's usually used for extreme use knives.
From Mike Stewart, who said he now uses XHP like Rick Hinderer does:
“It is fantastic but you will have to sign up for the passaround we are about to do here with one.
I have tested the heck out of it and so have a lot of others on my forum but we will have to wait till we see how all of you like it.
All I can tell you is that it is nothing at all like S30V except that it is a stain resistant alloy like S30V. It is a little more per pound but it is much easier to use for both the maker and the user.”
I like XHP blades a lot which I have from Hinderer and would use it for anything without a hesitation.
Rick Hinderer now makes xm-24 which supposed to be the toughest folder around and Rick decided to make the blade exclusively from CTS-HXP steel.
As he recently ran out of this steel he has to seize production of xm-24s till next year. It definitely tells me something.