Hardened Ultra-Wear-Resistant 440C Stainless Steel Ball
Grade 25, 18 mm Diameter
Precision Ball Grade | 25 |
Shape | Ball |
Diameter | 18 mm |
Diameter Tolerance | -0.0025 mm to 0.0025 mm |
Hardness | Rockwell C58 (Extra Hard) |
Specifications Met | ISO 3290 |
Magnetic Properties | Magnetic |
Appearance | Mirror Like |
Certificate Form | Digital |
Certificate Type | Material Certificate with Traceable Lot Number |
Construction | Solid |
Container Net Weight | 5 lb. |
Elongation | Not Rated |
Finish | Passivated |
Heat Treatment | Hardened |
Material | 440C Stainless Steel |
Material Composition | |
Carbon | 0.95% to 1.2% |
Chromium | 16% to 18% |
Copper | 0% to 0.5% |
Iron | 76.73% to 82.65% |
Manganese | 0% to 1% |
Molybdenum | 0.4% to 0.75% |
Nickel | 0% to 0.75% |
Phosphorus | 0% to 0.04% |
Silicon | 0% to 1% |
Sulfur | 0% to 0.03% |
Maximum Temperature | 800° F |
Minimum Temperature | Not Rated |
Performance | Corrosion Resistant, Chemical Resistant, Extreme Strength, Ultra Wear Resistant, Bearing Quality |
Tolerance Rating | Standard |
Warning Message | Physical and mechanical properties are not guaranteed. They are intended only as a basis for comparison and not for design purposes. |
Yield Strength | Not Rated |
Country of Origin | China, India |
DFARS Compliance | Specialty Metals COTS-Exempt |
Export Control Classification Number (ECCN) | 1C999 |
REACH Compliance | REACH (EC 1907/2006) (02/04/2026, 253 SVHC) Compliant |
RoHS Compliance | RoHS 3 (2015/863/EU) Compliant |
Schedule B Number | 848291.0020 |
U.S.–Mexico–Canada Agreement (USMCA) Qualifying | No |
The best choice for high-performance bearings and valves, these 440C stainless steel balls are among the strongest, hardest, and most wear-resistant we offer. They’re passivated to wash away surface particles that cause rust, and they’re polished to a mirror-like finish that contaminants can’t stick to. The result is balls that stay smooth and stand the test of time—even at temperatures up to 800° F. They’re made to strict ISO 3290 standards for roundness and surface quality.
These balls are magnetic, so you can use them in separators, sensors, and automated handling systems that use magnetic pickup or positioning.
Grade 25—Precision-ground to tighter tolerances than Grade 100 balls. Use them in high-accuracy assemblies.
The information in this 3-D model is provided for reference only.