Hardlock Industry

At HARDLOCK, we innovate safety and reliability through fastening solutions that never fail. Over 50 years ago, Katsuhiko Wakabayashi (1933–2024) invented the HARDLOCK Nut and went on to found HARDLOCK Industry Co, Ltd. The idea came to him during a visit to a Shinto shrine, where he noticed a traditional wooden wedge used in the gate structure—a simple, effective method for securely joining parts while remaining easily removable. That moment inspired the wedge concept behind the HARDLOCK Nut and led to a fastening solution trusted around the world. The wedge concept is what sets the HARDLOCK Nut apart—it applies a preload-independent transverse load to the bolt shaft. This locking effect prevents loosening, no matter the conditions. As a result, HARDLOCK is trusted in applications where safety and reliability cannot be compromised. Our product lineup includes: HARDLOCK Nut (HLN) – an all-metal, free-spinning locknut with industry-leading resistance to loosening through its wedge interface HARDLOCK Bearing Nut (HLB) – an all-metal bearing locknut that uses the same wedge design as the HLN to prevent loosening HARDLOCK Set Screw (HLS) – an all-metal set screw system derived from the HLN wedge concept, eliminating loosening in the most demanding environments All products are manufactured in Japan to the highest quality standards.