[Product Parameter] - Screw Dimension: M4 x 40mm (Thread Dia*Total L); Head Type: Slotted Flat Head; Package Content: 100pcs x Wood Screws [Material] - Made of brass for high strength, corrosion resistance, durability and long-lasting reliability. [Flat Head Design] - Flat head screws can keep the surface flat after installation. Self-tapping screws can go through wood products without pre-drilling. [Application] - A flat head screw is generally used when the protrusion of the fastener above the contact surface is not acceptable. It is widely used in construction, industry, commerce, etc. For example, woodworking, external and marine use. [Note] - Please wear gloves to protect your hands when working. Please allow 0.1mm-1mm measurement difference due to manual measurement.