Product & Tools : What's the Advantages of Ledger Lock Screws Ledger Lock Screws Board
Quote from What's the Advantages of Ledger Lock Screws :
To reduce the effect of friction between the ledgers lock screws head with the work-piece can be added to the ring / washer between the bolt head and the work-piece surface. Spiral-shaped washer on the bolt can be used to help prevent the connection strength is reduced due to the bolts loosen due to vibration. Construction bolt consists of a cylindrical rod that has a head on one end, and there is a groove along (or just at the end) of the cylinder rod. Bolts made of mild steel, alloy steel, stainless steel or brass. Bolts can also be made from metal or other metal alloys for special needs.