Hardware Essentials zinc and yellow dichromate clevis type grab hooks are designed with a clevis pin at the base for easy attachment. Grab hooks are designed with a narrow throat. Instead of a wide surface area for the rope or chain to rest on the hook grabs the chain or rope to help keep in place. Grade 70 is 20% stronger than grade 43. zinc and yellow dichromate plating is used for it's anti corrosion properties.