Stainless Steel Ball 420 Application Fields: 420 stainless steel balls are commonly used in industries that require high precision and corrosion resistance: motorcycle accessories, pulleys, stainless steel bearings, plastic bearings, handicrafts, valves, and oil. Material Comparison: Domestically, 420 stainless steel balls are mainly divided into two types: 2Cr13 steel balls (equivalent to Japanese standard SUS420J1 stainless steel balls) and 3Cr13 steel balls (equivalent to Japanese standard SUS420J2 stainless steel balls). Both types of balls have hardness, and many customers have a misunderstanding that 410 stainless steel balls (equivalent to Chinese standard 1Cr13 steel balls) and 430 stainless steel balls (1Cr17 steel balls) also have hardness. Although both are 4-series stainless steel balls, their microstructures are different: one is a martensitic steel, and the other is a ferritic steel. (All documents provided by our company are original; any similarities are coincidental and not plagiarism.) Characteristics: As a representative of martensitic steel, commonly known as stainless iron, it is magnetic, has good corrosion resistance, and high hardness of HRC 50-55.