A large number of M0.8‑M3 micro screws are adopted in consumer electronics and precision instruments. Material selection directly affects anti‑rust performance, assembly yield and service life. Many buyers only focus on dimensions while ignoring material difference, which causes rusting, fracture and magnetic interference in later stage.

SUS304 stainless steel micro screw is widely used in electronics industry with good rust resistance for ordinary indoor environment. Slight magnetism caused by cold working is normal and does not mean unqualified material. It has medium mechanical strength and higher cost compared with carbon‑steel screws.

Hardened & electroplated carbon‑steel micro screws feature high hardness and competitive price for mass‑production electronics. Yet its anti‑corrosion performance is limited. It is easy to get rust under humid condition, only suitable for dry inner cavity instead of exposed positions. Hydrogen embrittlement risk shall be noticed for tiny‑size screws from poor‑quality electroplating suppliers.

SUS316 stainless steel provides superior salt‑spray resistance over SUS304. It is applied for seaside outdoor electronics such as outdoor cameras and coastal monitoring instruments. Due to higher cost, it is only recommended for heavy‑corrosion scenarios.

Copper screws own good conductivity and non‑magnetic property for RF and signal‑related precision devices. However, mechanical strength is low and thread stripping happens easily, so they cannot be used for heavy‑load connections.

Practical selection advice: Electroplated carbon‑steel screws for dry inner‑part assembly to save cost. SUS304 for exposed or humid environment. SUS316 for coastal outdoor equipment. Copper material for RF signal devices. Regardless of material, tightening torque must be strictly controlled to prevent thread stripping and screw breakage.

For overseas procurement, verify material certificate, salt‑spray report and hardness test report to avoid non‑standard materials and ensure long‑term stability of electronic products.