Non-standard cold-forged carbon steel zinc-nickel alloy black enlarged meson washer hexagonal self-tapping screw is a high-performance fastener. Its customization function is achieved through the synergy of materials, processes, and structural design, as follows.
1. Material requirements
Base material: Various types of carbon steel; material certification is required.
Surface treatment: zinc-nickel alloy plating, salt spray test ≥500 hours.
Color: black, black passivation, or epoxy resin coating can be added, and the coating type needs to be indicated.
2. Size and structure
Screw type: external hexagonal self-tapping screw.
Head specification: external hexagonal head, opposite side size needs to be marked.
Washer integration: enlarged meson washer. Flat washer or spring washer, washer outer diameter ≥ 1.5 times the screw head.
Thread specification: non-standard self-tapping thread, need to provide drawings or mark pitch and thread length.
Total length range: 10mm~100mm, need to clarify whether the head height is included.
3. Processing technology
Forming technology: multi-station cold heading.
Heat treatment: quenching and tempering treatment, hardness HRC 28~32, or according to tensile grade, such as grade 8.8, grade 10.9.
Thread processing: thread rolling or thread rolling process (to ensure thread strength, no burrs).
4. Performance requirements
Tensile strength: ≥800MPa (corresponding to grade 8.8 and above).
Torque test: The breaking torque and tightening torque data must be provided.
Anti-corrosion performance: zinc-nickel plating + sealant, to ensure no white rust or red rust.
5. Surface and logo
Surface appearance: uniform without bottom exposure and no bubbles.
Head logo: brand LOGO or strength grade can be customized.
6. Packaging and delivery
Packing method: blister tray/roll packaging/bag packaging (rust-proof paper + desiccant).
MOQ: 5000~10000 pieces (small batches can be negotiated).
Delivery cycle: 15~30 days (need to confirm mold development time).
7. Additional services
Test report: provide third-party reports on material, coating thickness, hardness, etc.
Drawing confirmation: both parties need to sign and confirm non-standard drawings.
Note: Samples need to be provided for confirmation before mass production, and special requirements (such as no hydrogen embrittlement treatment, environmental protection RoHS) need to be stated in advance.
Through the above design, this screw has comprehensive advantages in strength, corrosion resistance, installation efficiency, and adaptability, meeting the stringent requirements of high-end industrial fields for fasteners.
