Description
CPM 154
This steel is manufactured in the USA and is supplied hot rolled and annealed. It has a textured surface from the hot rolling process and is soft and easily cut, ground, drilled, and filed. Exact thickness may vary from batch to batch.
CPM 154 stainless steel was developed by Crucible Industries in 2004 specifically for knifemakers. It is a modernised particle metallurgy version of the high temperature jet engine bearing steel 154CM and its Japanese equivalent ATS34, that became popular with both production and custom knifemakers after Bob Loveless started using it in the 1970s. The particle metallurgy process used to make CPM 154 gives it an even distribution of alloying elements, fine grain, fine carbide size, and greatly improved toughness over the ingot version of the same alloy.
One of the innovative features of the original alloy is the reduction in chromium and addition of 4% vanadium in its place, which improves hardenability, improves tempering resistance and hardness at elevated heat, and improves corrosion resistance.
Carbon – 1.05%
Molybdenum – 4.00%
Manganese – 0.50%
Silicon – 0.30%
Chromium – 14.00%
Iron – balance
Toughness 5/10 – Good toughness, better than most stainless steels but not as tough as most carbon steels. Suitable for small blades like slipjoint folders up to large blades like bowies and daggers.
Edge retention 4.5/10 – Better edge retention than any carbon steel and better than most stainless steels (approximately 20% better than 440C), almost as good as D2 tool steel; lower edge retention than vanadium stainless and tool steels like CPM S35VN, M390, or CPM M4. CPM 154 typically has better edge retention than tougher stainless steels, or, is tougher than higher edge retention stainless steels. This gives CPM 154 an optimal balance where it performs well in all areas and is easier to grind, hand sand, and polish compared to other premium stainless steels, making it popular with custom knifemakers where it can easily be hand finished to 600 grit or much higher.
Corrosion resistance 7/10 – Adequate resistance to rust, on par with many other common stainless steels like AEB-L and Nitro-V. The inclusion of 4% molybdenum in the alloy specifically improves its pitting resistance.
Recommended Heat Treatment
- Coat blade in an anti scale compound or seal in double crimped 321 or 309 grade stainless steel tool wrap
- Austenitise – heat to 1065°C and hold for 30 minutes (see note)
- Quench between aluminium plates, or air quench, or oil quench
- Immerse in liquid nitrogen or a dry ice slurry or place in a kitchen freezer for 1 hour or more – the lower the temperature the more austenite will be converted to martensite and the higher the as-quenched hardness will be
- Temper at 150-230°C for 2 hours, twice, depending on desired hardness
Note: If you are not using liquid nitrogen or dry ice as a cold treatment before tempering, lower austenitising temperatures will give better results – 1030°C with a freezer or no cold treatment, and temper at 200°C.
Alternatively, for maximum hardness suitable for small blades or high performance kitchen knives, austenitise at 1105°C for 20 minutes, liquid nitrogen or dry ice for 1 hour or more, then temper at 150°C for 2 hours, twice. This should yield a Rockwell C hardness of around 64 at a small reduction in toughness.
Recommended working hardness 60-64 HRC