Material:Carbon steel,rust-proof, wear-resistant, accurate, and smooth,Mainly used for positioning work in the connection of different equipment, often installed in parts that need to be disassembled frequently Package Includes:140 Pcs in total,there are 10Pcs 3*3*8mm,10Pcs 3*3*10mm,10Pcs 3*3*12mm,10Pcs 3*3*16mm,10Pcs 4*4*10mm,10Pcs 4*4*12mm,10Pcs 4*4*16mm,10Pcs 4*4*20mm,10Pcs 4*4*20mm,10Pcs 5*5*12mm,10Pcs 5*5*16mm,10Pcs 5*5*20mm,10Pcs 5*5*25mm,5Pcs 6*6*16mm,5Pcs 6*6*20mm,5Pcs 6*6*25mm,5Pcs 6*6*30mm,various sizes and sufficient quantities can meet your daily basic needs Easy to use:The flat key is round ended at both ends, integrally formed, easy to insert and install, and you can easily install it Easy to carry:All of the round ended feather key are packed in a plastic box with a clear label size by sizes for portable and convenient to store Widely used:Usually used for shaft key sets of various equipment such as machine tools, pulleys, axles, replacement parts for landscape, garden equipment and lawn mowers, etc. They are often used in factories, workshop machines, etc, and are ideal for machine tool fastening pieces, Manufacturer: BuxiuGK