NSM CruWear - Tool Steel Flat Bars

NSM CruWear - Tool Steel Flat Bars

NSM CruWear is a high-performance tool steel developed by Crucible Industries, designed to offer a balance between toughness, wear resistance, and edge retention. It is made through Crucible’s particle metallurgy process, which ensures a uniform distribution of carbides, enhancing its wear resistance and toughness compared to conventional ingot steels. NSM CruWear is often favored by knife makers for its ability to achieve high hardness without becoming brittle, making it suitable for a wide range of cutting applications.

Its composition, which includes vanadium and tungsten, results in excellent edge stability, while its lower chromium content compared to stainless steels makes it less corrosion resistant but improves toughness and ease of sharpening.

Composition

• Carbon – 1.10%
• Molybdenum – 1.60%
• Manganese – 0.30%
• Silicon – 0.90%
• Chromium – 7.50%
• Vanadium – 2.40%
• Tungsten – 1.10%
• Iron – Balance

Performance Characteristics

• Toughness 7/10 – CPM CruWear offers excellent toughness, particularly for a tool steel. It is tougher than CPM M4 and D2, making it suitable for hard-use knives, from small EDC knives to larger tactical and outdoor blades. It is also highly resistant to chipping, even at high hardness levels.

• Edge retention 7/10 – With its high vanadium and tungsten carbide content, CPM CruWear provides excellent wear resistance, offering edge retention superior to many stainless steels like CPM S35VN, while being easier to sharpen compared to higher-carbide steels such as CPM M4 or M390.

• Corrosion resistance 4/10 – Due to its relatively low chromium content (7.5%), CPM CruWear does not offer the same level of corrosion resistance as stainless steels. It can develop rust in humid or wet conditions, so proper care is recommended to prevent oxidation. However, it is more corrosion resistant than steels like 1095 or O1.

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 1050-1075°C and hold for 20-30 minutes
• Quench between aluminum plates or oil quench
• Cryogenic Treatment – For maximum performance, immerse in liquid nitrogen or dry ice slurry for 1 hour or more to convert retained austenite to martensite and increase hardness
• Temper at 150-250°C for 2 hours, twice, depending on the desired hardness

Note: For best results, cryogenic treatment is recommended after quenching. If no cryogenic treatment is used, aim for a lower austenitising temperature (around 1050°C) and temper at higher temperatures to achieve a balance between hardness and toughness.

Approximate As-Quenched Hardness Before Tempering:

• 1075°C followed by liquid nitrogen – 63-65HRC
• 1075°C followed by dry ice – 62-64HRC
• 1050°C followed by freezer – 61HRC

Recommended Working Hardness
60-64HRC