sample of what you will find there! CPM 3V, CPM 10V, CPM 420V and CPM(T)440V
CPM is a registered trademark of Crucible Materials Corp.
Information is posted with Crucible Materials Corp. permission
CPM S30V is the NEW addition from Crucible Materials Corp.
CPM S60V is a new designation for CPM 440V
CPM S90V is a new designation for CPM 420V.
CPM - Crucible Particle Metallurgy - steels are made by Crucible Specialty Metals, and are super edge holding steels.
The process used to manufacture particle metallurgy permits unusually high Carbon and Vanadium content.
About Particle Metallurgy
The traditional process uses the pressing of blended metal powders into a mold. The compacted part is then heated to just below the melting point. This is called sintering.
Sintering is similar to forge welding, since the individual particles are bonded without melting down. Parts can be produced that contain elements impossible to include in casting procedures.
Like making porous filters for gas and oil lines, sintered bronze self lubricated bearings, tungsten carbide cutting tool tips and replaceable ceramic inserts.
Crucible Specialty Metals company advanced the process of particle metallurgy in 1970 by introducing
Crucible Particle Metallurgy.
This process differs from traditional PM in that it is used to produce a large compact (billet), which is than rolled or forged in conventional mills into bars, rods, wire, sheet or plates required by the industry.
The wear resistance and strength of CPM steels are always greater than of the steels made by conventional methods. The fine grain size and even distribution of the alloy elements are the key.
Spyderco offers at least one model in CPM T440V
Comparison of CPM versus 440-C and 154CM Stainless:
Carbon Manganese Silicon Chromium Molybdenum Vanadium
440 C 1.20 1.00 1.00 18.00 0.75 0.00
154 CM 1.02 0.60 0.25 14.00 4.00 0.00
CPM 3V 0.80 0.50 0.90 5.23 1.30 9.75
CPM 10V 2.46 - - 7.50 1.30 2.75
CPM S60V (440V) 2.30 - - 14.00 1.00 9.00
CPM S90V (420V) 2.15 0.40 0.40 17.00 0.40 5.50
CPM S30V 1.45 0.40 0.40 14.00 2.00 4.00
Heat treating
Preheat at 1500 - 1550 degrees F and hold for about 1/2 hour. Transfer to furnace heated to 1950-2150 degrees F, depending on the temperature selected.
- 1,950 degrees F is recommended for maximum toughness,
- 2,150 degrees F is recommended for maximum wear resistance.
To ensure adequate solutioning of the alloy carbides and proper response to tempering, a minimum soak time of 30 minutes at temperature is recommended for hardening from 1950 degrees F, and a minimum soak time of 10 minutes at temperature for hardening from 2150 degrees F.
These times should be adjusted accordingly for large or very thin section sizes.
Air quench. Temper immediately.
Edge holding ability is said to be 2 - 3x better than 440C at 57 - 58RC.
CPM steels are easier to grind and polish than conventional stainless.
440-V available SIZES
Hot Rolled 1/8" thick x 1-1/2" wide x 1' + and 36" long - Orange End
3/16" thick x 1-1/2" wide x 1' + and 36" long - Orange End
1/8" thick x 1-1/2" wide x 18" and 36" long - White End
5/32" thick x 1-1/2" wide x 18" and 36" long - White End
3/16" thick x 1-1/2" wide x 18" and 36" long - White End
3/16" thick x 2" wide x 18" and 36" long - White End
Precision ground 3/32" thick x 1-1/2" wide x 18" and 36" long - White End
1/8" thick x 1-1/2" wide x 18" and 36" long - White End
Sheet 3/32" thick x 6" wide x 12" long - Orange End
3/32" thick x 6" wide x 24" long - Orange End
3/32" thick x 6" wide x 36" long - Orange End
CPM S30V - is a martensitic stainless steel designed to offer the best combination of toughness, wear resistance and corrosion resistance.
It's chemistry has been specially balanced to promote the formation of vanadium carbides which are harder and more effective than chromium carbides in providing wear resistance.
S30V offers substantial improvement in toughness over other high hardness steels such as 440C and D2,
and its corrosion resistance is equal to or better than 440C in various environments.
The CPM process produces very homogeneous, high quality steel characterized by superior dimensional stability, grindability, and toughness compared to steels produced by conventional processes.
Current Data Sheets are available in HTML and PDF formats at company's web site:
http://www.crucibleservice.com/datasheets/dynamicPull.cfm?gradeName=CPM S30V
Heat treatment of CPM S30V
Forging: 2100°F (1150°C) Do not forge below 1750°F (950°C).
Annealing: Heat to 1650°F (900°C), hold 2 hours, slow cool no faster than 25°F (15°C) per hour to 1100°F (595°C), then furnace cool or cool in still air to room temperature.
Annealed Hardness: About BHN 255
Stress Relieving
Annealed Parts: Heat to 1100-1300°F (595-705°C), hold 2 hours, then furnace cool or cool in still air. Hardened Parts: Heat to 25-50°F (15-30°C) below original tempering temperature, hold 2 hours, then furnace cool or cool in still air.
Straightening: Best done warm 400-800°F (200-430°C)
Hardening Preheat: Heat to 1550-1600°F (845-870°C) Equalize.
Austenitize: 1900-2000°F (1035-1095°C), hold time at temperature 15-30 minutes.
Quench: Air or positive pressure quench (2 bar minimum) to below 125°F (50°C), or salt or interrupted oil quench to about 1000°F (540°C), then air cool to below 125°F (50°C).
Temper: Double temper at 400-750°F (200-400°C). Hold for 2 hours minimum each time.
A freezing treatment - may be used between the first and second tempers. Freezing treatments help to attain maximum hardenability and must always be followed by at least one temper.
NOTE: For optimum stress relieving, CPM S30V may be tempered at 1000-1025°F (540-550°C). Tempering in this range may result in a slight decrease in corrosion resistance. Size Change: +0.05 to +0.10% when fully martensitic. The presence of retained austenite may reduce the net growth.
When tempering at 400-750°F (200-400°C), freezing treatments may be necessary to minimize retained austenite.
Note: Properties shown throughout this data sheet are typical values. Normal variations in chemistry, size and heat treat conditions may cause deviations from these values. For additional data or metallurgical assistance, please consult your local Crucible Service Center.
Recommended Heat Treatment:
Austenitize 1950°F (1065°C). Quench to below 125°F (50°C). Double temper at 600°F (315°C) 2 hrs. minimum each temper. Cool to hand warm between tempers. A freezing treatment may be added between tempers.
Aim hardness: 58-61 HRC.
Listed in the catalog of:
Sheffield's Knifemakers Supply
Texas Knifemaker's Supply
Boxcutters have thin blades and are designed just for that specific purpose (and priced accordingly). Just because somebody was clumsy enough to cut himself with one doesn't mean they are inappropriate tool for the job ... what would you boss have said if you told him about all the times you've cut yourself fiddling with your knives ? 
