Product Overview
The Phillips Drive Combo Screw is an integrated fastening component consisting of a Phillips drive machine screw, a flat washer (SAE type), and a spring (split) lock washer pre-assembled in sequence. This pre-combined unit streamlines the assembly process by eliminating the need to handle three separate parts, reducing inventory complexity, and ensuring the correct washer arrangement for optimal performance. It is designed for efficient, high-volume production in applications requiring secure, vibration-resistant fastening with a finished appearance.
Key Advantages
Assembly Efficiency: Reduces part count and handling time, speeding up production lines and lowering total assembly cost.
Ensured Correct Sequence: Guarantees the proper installation order (screw > flat washer > spring washer), which is critical for effective load distribution and locking function.
Vibration Resistance: The pre-assembled spring washer provides maintained tension to resist loosening under dynamic loads.
Surface Protection: The flat washer distributes clamp load, protecting soft or finished surfaces from damage.
Inventory Simplification: Manages one SKU instead of three, simplifying logistics and procurement.
Material Specifications & Strength Grades
| Component | Material Standard | Grade / Class | Key Characteristics |
|---|---|---|---|
| Screw | Low/Medium Carbon Steel | 4.8 / 8.8 | Grade 4.8: General purpose. Grade 8.8: Quenched & tempered for higher strength. |
| Flat Washer | Low Carbon Steel (ASTM AISI 1008/1010) | – | Provides bearing surface, protects assembled material. |
| Spring Washer | Spring Steel (ASTM AISI 1065/1070) | – | Hardened (HRC 40-50) to provide spring action and locking force. |
Standard Series & Specifications
Screw Drive & Head: Phillips Cross Recess (PH), compliant with ISO 8764. Pan head or countersunk head styles are common.
Washer Standards: Flat washer conforms to general SAE or ASME B18.22.1 dimensions. Spring lock washer conforms to ASME B18.21.1 or DIN 127.
Thread Systems: Available in Machine Screw Threads (Metric: M3, M4, M5, etc.; Imperial: #6-32, #8-32, #10-24, etc.).
Pre-Assembly: The washers are loosely assembled onto the screw shank and are free-spinning until tightened, allowing for normal installation.
Available Surface Finishes
| Finish Type | Specification / Process | Application & Benefit |
|---|---|---|
| Zinc Plated, Blue/Yellow/Trivalent Chromate | ASTM B633 | Standard corrosion protection. Trivalent chromate is RoHS/REACH compliant. |
| Zinc-Nickel Alloy Plating | – | Enhanced corrosion resistance for demanding environments (e.g., automotive underbody). |
| Phosphated & Oiled | – | Good break-in lubrication and mild corrosion resistance. |
| Geomet®-type Coating | Proprietary | Dry-film, lubricious coating offering excellent corrosion resistance and consistent torque-tension relationship. |
Application Notes
Typical Uses: Electrical enclosures, HVAC equipment, automotive interiors and trim, furniture assembly, appliance manufacturing, and general sheet metal fabrication.
Installation: Use a correctly sized Phillips bit (PH1, PH2, PH3) to prevent cam-out and recess damage. The washers will self-align during tightening.
Torque Values: Follow torque recommendations based on the screw’s grade, size, and application. The presence of washers may slightly affect the final clamp load.
Quality Assurance
Our combo screws are manufactured and pre-assembled under a certified ISO 9001:2015 quality management system. We perform dimensional checks on all components, salt spray testing on finished products, and mechanical tests (hardness, torque-to-yield) on screw samples to ensure consistent performance.
Manufacturing Expertise
Hebei Wohe Fastener Manufacturing Co., Ltd. specializes in the integrated production and assembly of component fasteners. Our process controls ensure the compatibility and quality of each element—the screw, flat washer, and spring washer—before they are assembled into a single, reliable unit. This vertical integration, combined with over 15 years of experience in serving the electronics, automotive, and general manufacturing sectors, guarantees a product that meets the efficiency demands of modern assembly lines.
Availability: Wide range of standard size combinations in stock.
Customization: Options include different screw grades, various plating finishes, and alternative washer types (e.g., star washers).
MOQ: Standard items start from 10,000 pieces. Custom combos are negotiable.
Lead Time: Standard items: 15-20 days. Customized orders: 25-30 days.
Note: The pre-assembled washers are designed for convenience and are not permanently locked in place until installation. For applications involving extreme vibration, additional locking methods may be required. Always verify the compatibility of screw length with your material thickness when using pre-assembled washers.
