High-Strength Stainless Steel Fasteners
In our previous edition (Vol.17), we discussed how it is possible to specify the exact material of austenitic stainless steels in the A2 and A4 categories in Japan.
By increasing the tensile strength of the wire-drawn material to a certain level, it becomes possible to manufacture high-strength stainless steel fasteners from A2 and A4 grades, which cannot undergo heat treatment. This is one of the unique strengths of Japanese fastener manufacturing.
For example, if A2-grade material is drawn to achieve a tensile strength of just under 700 N/mm², it is then relatively easy to reach tensile strength levels exceeding A2-70 through subsequent heading and thread rolling processes.
Furthermore, by carefully designing the cold forming process to include both compressive and tensile stress stages, the mechanical strength of the fastener can be further enhanced—making it possible to produce high-strength grades such as A2-80 and A2-90.
A4-grade stainless steels, such as SUS316, generally have higher strength than A2 grades due to the addition of molybdenum (Mo). By reducing the diameter during the wire drawing process and applying cold forging, materials such as SUS316 or SUS316L can also achieve even greater strength.
While A4-80 class high-strength fasteners are available in Europe, Japan is capable of producing even higher strength fasteners, such as A4-100.
For more details, please contact 310 Express Company, the export division of the SAIMA Group and a team of specialists in sourcing high-grade fasteners made in Japan.
【Writer】Tak Saima/CEO, Technical Sales