Thread size: M4 x 0.7mm.Size: (overall) 12x8mm / 0.47"x0.31"; thickness(knurled part): 3.8mm / 0.15".Material: Made of good quality metal, nickel plated finished, wear-resisting and durable to use.Advantage: This facilitates tightening by hand, commonly used in electronics applications.Common on 3d printer beds, machine tools, cabinets, tool boxes, and great for maker projects and things that need adjusted quickly. Works with M3 bolts, studs and screws with a 0.5mm pitch.