M3 M4 Stainless steel Hex Flange Self Tapping metal Screws SS304 SS316 A2 A4-80 Drilling screws

There are two types of self-tapping screws: round head and flat head. They require a pilot hole to be drilled into the material that is slightly smaller than the diameter of the screw before a screwdriver is used to screw the screw into the material. Self-tapping screws with a pointed head do not require a pilot hole. Self-tapping threaded screws are suitable for fixing materials such as wood, plastic, metal and brick.

Self-tapping screws can also be classified as self-tapping locking screws, wall panel self-tapping screws, self-drilling self-tapping screws, general self-tapping screws, etc., depending on their use.

• Generally manufactured from carburised steel (99% of total production). Can also be manufactured from stainless steel or non-ferrous metals.
• Product must be heat-treated. Carbon steel self-tapping screws must be carburised, and stainless steel self-tapping screws must be solution-hardened.
• High surface hardness, good core toughness - 'soft and rigid'. This is a major feature of the performance requirements of self-tapping screws.
• Surface of the product requires surface protection treatment, generally plating treatment. Some products may be treated with phosphate (phosphating).
• Cold heading process is adopted using high-speed machines to ensure product quality with good head forming and high thread quality.
• A2
  Material: corresponds to SUS304 (Stainless Steel 304)
  Characteristics: General-purpose stainless steel, good corrosion resistance, suitable for most daily environments
  Common grade: A2-70 (tensile strength ≥700 MPa)
• A4-80
  Material: corresponds to SUS316 (stainless steel 316)
  Characteristics: Containing molybdenum (Mo), more corrosion-resistant than 304, especially suitable for marine, chemical and other highly corrosive environments.
  Strength grade: 80 means tensile strength ≥800 MPa.
  Cold work hardening treatment: Since austenitic stainless steel cannot be strengthened by heat treatment, A4-80 is cold worked to improve strength.