Description:
1.Machine screws are often used with nuts but also often driven into tapped holes.
2.Oftenr used to hold object to another object that has a pre-threaded hole, frequently a nut.
3.They might be considered a screw or a bolt based on the Machinery's Handbook distinction.
4.A flat head is a head with flat top and a conical bearing surface (bottom). This one is designed to be Countersunk.

Specifications:
Standard: GB/YB 819
Material: 304 Stainless Steel
Drive Type: Phillips/Flat
Screw Size: M4x40
Thread Pitch: 0.7mm
Total Length: 39.5~40.5mm/1.555"~1.594"
For detailed size, please refer to the product picture.