The magnitude of the stress in the stainless steel cap's microstructure is related to factors such as the cooling rate, shape, and chemical composition of the material within the martensite transformation zone. The stress variation in the stainless steel cap results in tensile stress on the surface and compressive stress in the core, which is opposite to the thermal stress. Practice has proven that during the heat treatment process, any workpiece will experience both thermal and microstructural stresses as long as there is a phase change. However, thermal stress occurs before the microstructural transformation in the stainless steel cap, while microstructural stress is generated during the transformation process. Throughout the cooling process, the combined effect of thermal and microstructural stresses results in the actual stress present in the workpiece.

Stainless steel end caps are widely used in industries such as oil, electronics, heating, chemical processing, wastewater treatment, light industry and textiles, food, machinery, construction, nuclear power, aerospace, pressure vessels, and military industry.