440C Stainless Steel Bar (1.4125)

440C stainless steel bar (EN 1.4125 / AISI 440C / UNS S44004) is a high-carbon, straight-chromium martensitic stainless steel grade used where very high hardness, strength and wear resistance are required. It is commonly supplied in the annealed condition to support machining, and it can then be hardened and tempered to achieve high performance in service.

Overview
440C is selected for demanding mechanical applications where abrasion resistance and edge retention are important. When properly hardened and tempered, 440C stainless steel bar offers excellent strength and hardness alongside good corrosion resistance for a martensitic grade. It can be through-hardened and is capable of reaching very high hardness levels (often up to around 60 HRC depending on heat treatment and section size).

Key benefits

• Very high achievable hardness and strength after heat treatment
• Excellent wear and abrasion resistance
• Good corrosion resistance for a high-carbon martensitic grade
• Supplied annealed to support machining prior to heat treatment

Machining and heat treatment notes
440C stainless bar typically machines best in the annealed condition. Where a component requires maximum hardness and wear resistance, the part is usually machined first and then heat-treated (hardened and tempered) to the required properties. If you require a specific condition, hardness range or heat treatment route, our team can advise on availability and typical supply options.

Welding and fabrication limitations
Welding 440C is generally not recommended, particularly after hardening and tempering, due to the risk of cracking and property changes. If welding is unavoidable, it is normally considered only in the annealed condition and should be approached with appropriate specialist guidance and procedures.

Typical applications
440C stainless steel bar is commonly used for high-wear components and parts requiring high hardness, including bearings, shafts, valve parts, tools and precision components subject to abrasion, sliding wear or repeated loading.

Supply note
Below is our standard size range for 440C stainless steel bar. If you do not see the size or quantity you need, please contact our team, and we will help with availability, lead times and a quote.