AISI 440C Stainless Steel Balls for Precision Bearings and Valves
REDHILL supplies AISI 440C stainless steel balls for bearings, valves, couplings and precision mechanisms. This high-carbon stainless steel develops high hardness through heat treatment. As a result, it suits parts that face repeated rolling or seating contact.
Material Designations: AISI 440C (UNS S44004); common European references include 1.4125 and X105CrMo17.
Key Technical Specifications
The following figures provide typical material reference values. Therefore, confirm the required material standard and condition when ordering.
- AISI 440C Composition: Carbon 0.95–1.20%, chromium 16–18%, molybdenum ≤0.75%, manganese ≤1.0%, silicon ≤1.0%, iron balance.
- Structure: Hardened and tempered martensitic stainless steel.
- Hardness: Typically 58–65 HRC, depending on heat treatment and ball size.
- Tensile Strength: Approximately 1,965 MPa (285,000 psi), typical for hardened material around 60 HRC.
- Density: Approximately 7.75 g/cm³.
- Magnetic Properties: Magnetic material.
Hardness, Wear and Corrosion Resistance
High hardness helps resist wear during repeated contact. In addition, a smooth finish supports consistent contact with the mating surface. Therefore, match the ball grade and surface finish to the bearing race, valve seat or contact part.
However, corrosion resistance varies with the fluid, temperature and surface condition. For example, saltwater and some acids can attack this steel. Also check compatibility with cleaning agents and process fluids.
Applications of AISI 440C Stainless Steel Balls
For example, common uses include:
- Ball Bearings: Rolling elements in precision and miniature bearings.
- Valves and Pumps: Check balls and sealing elements for compatible fluids.
- Couplings and Locking Devices: Balls for retention and release mechanisms.
- Actuators and Instruments: Precision contact and locating elements.
Available Grades and Sizes
- Precision Grades: G5–G100.
- Diameters: 0.3–101.6 mm (up to 4 inches).
Available combinations depend on diameter, grade and material condition. Finally, send us your ball size, grade, quantity and working conditions. We can then confirm suitable options, availability and lead time.