440 Stainless Steel Ball Specifications

The annealing temperature for 440 stainless steel balls is low, and during heat treatment for tools and bearings, the recommended hardness is between HRC57-59. If subjected to deep cryogenic treatment, the hardness can reach HRC60.

440 Stainless Steel BallStainless steel is a high-carbon, high-chromium martensitic stainless steel. Carbon content is 1.0%, and chromium content is 17%. Application range:

The 440 stainless steel balls are primarily used for manufacturing bearing components that operate in corrosive environments and under non-lubricated, strongly oxidizing atmospheres. Known for their good high-temperature dimensional stability, they can also be utilized as corrosion-resistant high-temperature bearing steel. Additionally, they are suitable for producing high-quality tools such as surgical knives, scissors, nozzles, and bearings. However, the 440 stainless steel balls have a lower capacity to withstand dynamic loads.

The SUS440 stainless steel ball is a martensitic stainless steel with a higher carbon content than the 3Cr13 steel, thus offering higher strength and hardness. Its other properties are similar to those of the 3Cr13 steel, but it has poor weldability and is generally not used as welding material. It is commonly used in the production of surgical medical instruments. Imported from Japan, this stainless steel is suitable for manufacturing bearing components that operate in corrosive environments and under high-temperature, non-lubricated oxidation conditions. The steel also exhibits good high-temperature dimensional stability, allowing for the production of corrosion-resistant high-temperature bearings and tools with temperatures not exceeding 250°C.

Hardness: Annealed, ≤269HB; Quenched and tempered, ≥55HRC

Heat Treatment Standards: 1) Annealing, cooled slowly to room temperature at 800～900℃; 2) Quenching, oil-cooled at 1000～1050℃; 3) Tempering, air-cooled at 200～300℃.