1、A2‑70 Material: Adopting high quality A2‑70 steel material, not easy to deform, very durable for long use. 2、Exquisite Craft: Having been through black galvanizing process, these countersunk is pretty and reliable. 3、Extensive Using: Allows for flexible application of fixing on various materials and for connection as well. 4、50Pcs in 1 Set: There are 50pcs flat screw in the set, which will largely satisfy the replacement needs. 5、Easy to Install: M4 type enables convenient installation with PZ2 screwdriver, also very easy to carry. Item Type: Countersunk Screw Material: A2-70 Product Model: M4 Standard: DIN 965 Process: Black Galvanized Thread Diameter: Approx. 4mm / 0.16in Pitch: Approx. 0.7mm / 0.03in Screw Head Height: Approx. 2.2mm / 0.09in Head Diameter: Approx. 7.3mm / 0.29in Screwdriver Size: PZ2 Black Zinc Plated Explained These screws are standard zinc plated screws with a decorative black coating applied. The dip spin black coating offers a slightly increased level of protection against corrosion and is very thin so will not interfere with the threads, there is no build up in the threads or recess on the heads. The coating is solvent based and is resistant to chemicals and is also RoHS2 compliant. Please note though that due to the thin application on these screws, it is possible that the coating may scratch slightly. 50 x M4x30 Screw