Features Made of 45 steel ,black oxide finish, features high hardness, high strength, durable in use It is used for T-slot aluminum extrusions to connect other parts Undersized to fit machine table slot case hardened Bottom of T-Slot nut Is staked to prevent the stud from protrusion T-Slot nuts enable the user to add clamps to a fixture without tearing down existing clamps Features: Made of 45 steel, black oxide finish, features high hardness, high strength, durable in use. Undersized to fit machine table slot case hardened. It is used for T-slot aluminum extrusions to connect other parts. Bottom of T-Slot nut is staked to prevent the stud from protrusion. T-Slot nuts enable the user to add clamps to a fixture without tearing down existing clamps.    Specifications: Material: 45 steel Surface treatment: black oxide Thread: M12 Size: as the picture Weight: 235g Package Included: 5 x  T Slot Nuts Package List