Astm A193 Plain Triangular Flat Csk Head Security Metal Screw Anti Theft Screw M3 M4

This security screw features a triangular recess drive with a flat countersunk (CSK) head for flush installation. Conforming to ASTM A193 material specifications, the screw is made from high‑quality alloy steel or stainless steel (plain finish as standard). The triangular drive is designed to accept only a matching triangular bit, providing effective anti‑theft protection. The countersunk head allows the screw to sit below or level with the workpiece surface, making it difficult to grip with pliers or other extraction tools. Available in M3 and M4 sizes, these screws are commonly used in panels, signage, and light‑duty security applications.

• Street furniture – bench planks, litter bin access panels.

• Electrical switchgear covers in public buildings.

• Signage and advertising displays – prevents unauthorised removal.

• University and school laboratory equipment housings.

• Access covers on vending machines and ticket validators.

• Countersunk head – sits flush, cannot be grabbed by hand tools.

• Triangular drive – requires dedicated key, blocks standard bits.

• ASTM A193 material – reliable mechanical properties for structural use.

• Plain finish – suitable for indoor applications or as base for painting.

• M3/M4 sizes – cover small to medium panel mounting needs.