Features These are multipurpose hexagon socket screws that you can easily drive with an Allen key These set screws are made of 12.9 grade alloy steel for high hardness, durability and long life Get these 200 pieces of screws in total so you don't have to run to the hardware store for quite a while to get a set screw Well packaged and sorted in a transparent resealable box for convenient carrying and storage There are 10 common sizes and you can focus on your project without worrying about not having the right screws Description: A set screw is a type of screw that is generally used to attach an object in it or against another object without using a nut. The most common examples attach a pulley or gear to a shaft. Set screws are fully threaded and have no head that protrudes beyond the main diameter of the screw thread. These set screws are powered by a hexagon socket drive. Specifications: Material: 12.9 grade alloy steel. Colour: black. Type: cup point with hexagon socket. Size and quantity: 20 pieces M3 x 3 mm. 20 pieces M3 x 4 mm. 20 pieces M3 x 6 mm. 20 pieces M4 x 4 mm. 20 pieces M4 x 6 mm. 20 pieces M5 x 5 mm. 20 pieces M5 x 8 mm. 20 pieces M6 x 6 mm. 20 pieces M6 x 10 mm. 20 pieces M8 x 8 mm. Box size: 13 x 6.5 x 2.3 cm / 5.11 x 2.56 x 0.9 inches. Package includes: 200 x screws Package List