Polypropylene (PP) plastic balls are made from a lightweight thermoplastic polymer (density 0.90-0.91 g/cm³) with excellent chemical resistance. They are non-toxic, FDA-compliant, and often include UV stabilizers for outdoor use.

With an elastic modulus of 200-210 GPa and thermal expansion coefficient of 11.5-12.5×10⁻⁶/°C, they maintain stability in temperatures from -50°C to 150°C, suitable for varied operating conditions.

They offer high precision with grades G10-G200 (tolerances ±0.0025mm to ±0.025mm) and a surface roughness of Ra 0.02-0.05μm, ensuring smooth, low-friction performance in high-speed or precision applications.

They are used in rolling bearings, grinding media, valves, and mechanical transmission systems, particularly in automotive (e.g., gearboxes), industrial machinery, mining equipment, and precision instruments.

Alloy steel balls are made from low-alloy steels like CG40Cr, CG08, or SAE8620, containing elements such as chromium (0.4-1.1%), nickel (up to 0.7%), and molybdenum (up to 0.25%). These elements enhance hardness, toughness, and wear resistance.

Low carbon steel balls are made from steel alloys with 0.05–0.3% carbon, such as AISI 1010, 1015, or 1018. They primarily consist of iron with trace amounts of manganese, sulfur, and phosphorus, but lack significant alloying elements like chromium. They are typically case-hardened or left soft for specific uses.

High carbon steel wire (e.g., AISI 1085) is cold-headed into blanks, flashed, and ground. The balls are then heated to ~1500–1600°F, quenched to lock in hardness, and tempered to reduce brittleness. Final grinding and polishing ensure dimensional accuracy and smooth surfaces. They meet ABMA standards for sphericity and tolerance (e.g., ±0.0001" for Grade 100).

• Hardness: Through-hardened to HRC 60–65, providing uniform hardness throughout.
• Wear Resistance: High, suitable for heavy loads and wear-intensive applications.
• Corrosion Resistance: Poor; prone to rust in humid or wet conditions without protection.
• Magnetic: Fully magnetic, ideal for applications requiring magnetic properties.
• Load Capacity: Excellent for higher loads compared to low-carbon steel, but more brittle.
• Sizes and Grades: Available from 0.5mm to 50.8mm, in ABMA grades 100–1000 for varying precision.

High carbon steel balls are made from steel alloys with 0.6–1.2% carbon, such as AISI 1060, 1070, or 1085. They contain iron as the primary element, with trace amounts of manganese, sulfur, and phosphorus, but minimal alloying elements like chromium (unlike chrome or stainless steel). They are typically through-hardened for uniform strength.

• Grade 100: Ultra-precise (±0.0001" deviation), for semi-precision bearings.

• Grade 500–1000: Commercial tolerance (±0.0005–0.001"), for casters, slides, toys. High-carbon balls are more common in higher grades for demanding applications.