Descriptions:ThisT slot nuts are 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. Bottom of T-Slot nut is staked to prevent the stud from protrusion. 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 oxideThread: M14Size: as the pictureWeight: 277gPackage Included:5 x T Slot Nuts