Screw A4

Screw A4 is a fastener made of austenitic alloy containing 2-3% molybdenum. Structurally, it is a cylindrical threaded shank with a head featuring a slot or cross recess for driving with a screwdriver.

Stainless steel screws of grade A4 are resistant to acids, chlorine-containing substances and seawater. They retain their performance properties at temperatures from -60 to +450°C over an extended service life.

A4 screws vary in length and diameter. By head shape, the fasteners can be:

• countersunk and raised countersunk head;
• with a cylinder head;
• round (button) head;
• with a flange or headless.

By application, A4 stainless steel screws are divided into fastening and mounting types. Fastening screws are used for detachable threaded joints. Mounting (set) screws fix parts in a given position. The end sections of A4 set screws are made conical, cylindrical or flat — for ease of installation. The field of application spans a wide range of industries.