by Shun Otsuki
President & Editor in Chief KINSAN FASTENER NEWS
Nitto Seiko (Ayabe City, Kyoto Prefecture) as changed the product name of its new clinching stud bolt to JOISTUD-S, which went on sale on February 1 this year.
The company has been developing and improving JOISTUD for more specialized applications, which is currently gaining a good reputation mainly among users in the automotive industry, where EVs are increasingly being used. In response to numerous requests, three types of JOISTUD products (high non-turnover strength, space-saving, and waterproof function) have been developed and launched on February 1, 2023. Patents have already been applied for for all products. In conjunction with the new name change, the company has also adopted a new product logo, which will be used extensively in future product PR. The company aims to ship 2 million units per month of the series in FY2023.
The JOISTUD series uses a non-turn projection with only the lobed edge left in a ring shape instead of the uniformly thick lobed non-turn projection used in conventional clinching stud bolts, thereby reducing the load on the fastening member during press-fitting and suppressing warpage of the member. In addition, the inner recess of the non-turn projection can accommodate the fastening member that is deformed during press-fitting, preventing this deformed part from protruding from the thread side and becoming a burr, and improving the non-turn strength in the rotational direction. The product lineup is as follows
High-torque type "JOISTUD-HT (High-Torque)" = The addition of a projection with a gentle slope toward the center from the outer portion of the lobe provides an even higher anti-turn effect. The anti-torque strength has been improved by approximately 22%.
Space-saving type "JOISTUD-SS (Space-Saving)" = By setting a height difference between the outer and inner portions of the non-turn protection projection and an angle difference in the slope, the load on the mating material during press-fitting is reduced and warpage of the mating material is suppressed. This reduces the load on the mating material during press-fitting and realizes a smaller head while suppressing warpage of the mating material. This solves the issues of space saving and weight reduction.
Waterproof type "JOISTUD-WP (Water Proof)" = The unique structure enables press-fitting without crushing the O-ring incorporated in the stepped section. When fastening the mounting part, the O-ring is compressed to realize waterproofing at the interface between the mounting part and the mating material. After the fastening part was immersed in 30 cm of water and left for 30 minutes, no water was found to have entered the enclosure, confirming that the waterproof performance is maintained.
