A JCB made of stainless steel One kind of fastener that stands out is the Allen Bolt, which is made of stainless steel and has endurance and corrosion resistance. An "Allen Bolt" is a bolt with a hexagonal socket head that is intended to be tightened or loosened with an Allen wrench, also known as a hex key. Because of their robustness and dependability under harsh conditions, these bolts are frequently found in heavy gear, including JCB equipment. They are appropriate for uses that call for corrosion and rust resistance along with a secure fastening.