Below is a list of Industrial Bolts manufacturers from Harleysville, Pennsylvania. An industrial bolt is a type of mechanical fastener with a threaded body that is driven through two adjacent surfaces for the purpose of adjoining them securely in high stress situations. Bolts, which are extremely versatile, can be categorized as sex bolts, T-head bolts or toggle bolts. These broad groupings are used to narrow down the specific type of bolt needed as there are dozens of possibilities.