【100 Pcs, 5 Sizes, M3 Hex Socket Head Cap Screws + 1 Pcs Hex Key Come In a Plastic Storage Box】 ✔ Contains 100 Pcs M3 hex socket head cap screws --Meets/exceeds: DIN912 --Screw head style: socket cap head, head diameter: 5.50 mm ( Range: 5.50 ± 0.18 mm), Head Height: 2.93 mm ( Range: 2.93 ± 0.07 mm) --Screw drive style: hex socket drive, also known as internal hex drive, hex size: 2.5 mm --Made of Stainless steel 304, high strength and anti-corrosion in various conditions --Thread size ( diameter ): 3 mm, thread Pitch: 0.5 mm --Thread length from 30 to 50 mm: [ Items ]-----[ Thread Length ]-----[ Total Length ( Includes Head ) ] M3 x 30mm----- 30 ± 0.50 mm-----32.93 ± 0.57 mm M3 x 35mm----- 35 ± 0.50 mm-----37.93 ± 0.57 mm M3 x 40mm----- 40 ± 0.60 mm-----42.93 ± 0.67 mm M3 x 45mm----- 45 ± 0.60 mm-----47.93 ± 0.67 mm M3 x 50mm----- 50 ± 0.60 mm-----52.93 ± 0.67 mm ✔ Contains 1 Pcs hex key to drive these screws conveniently and easily --Hex size: 2.5 mm --Made of chrome-vanadium steel, nickel plated, higher strength, anti-rust ✔ Easy to store: These 100 Pcs M3 hex socket head cap screws and 1 Pcs Hex Key come in a plastic storage box, organized conveniently and easily [ Package Contains ] M3 x 30mm---20 Pcs M3 x 35mm---20 Pcs M3 x 40mm---20 Pcs M3 x 45mm---20 Pcs M3 x 50mm---20 Pcs Hex Key----1 Pcs [ What is Hex Socket Drive ] Hex Socket Drive, also known as Internal hex drive, have a hexagonal hole in the center that requires an Allen key, also known as a hex key or Allen wrench [ What is Socket Cap Head ] Socket Cap Head , also known as Allen head, have a recessed drive, and are commonly used when there is not enough clearance for a conventional wrench or socket. They are fastened with an Allen wrench, which is also called a hex wrench or hex key