Ou rthree-in-one pre-assembled combination screws integrate screw, flat washer and spring washer into one finished unit, covering full specs from M5, M6, M8 to M10 with varied lengths such as M5×10, M6×12, M8×18, M10×16. Available in Phillips, slotted, hex socket, torx and outer hex head types with stainless steel or carbon steel zinc-plated finish. Pre-installed washers eliminate separate gasket assembly, deliver reliable anti-loose cushioning, perfectly suited for electric meter shell, terminal block and distribution box assembly in power industry projects worldwide.
| System of Measurement | Metric |
|---|---|
| Material | 304 Stainless Steel, Zinc-plated Carbon Steel |
| Available Spec | M5×10, M6×12/M6×80, M8×16/M8×18/M8×19, M10×16, custom non-standard dimension |
| Head & Drive | Phillips, Slotted, Hex Socket, Torx, Outer Hex, Recessed Hex Head |
| Washer Combination | Pre-mounted Flat Washer + Spring Washer (3-in-1 integrated) |
| Surface Finish | Zinc Plating, Stainless Steel Natural Passivation |
| Production Process | Cold Heading, Thread Rolling, Automatic Washer Pre-assembly |
| Executive Standard | ISO, DIN, GB, ANSI, Custom Drawing Specification |
| Grade | 4.8/8.8 Grade Carbon Steel, A2-70 304 Stainless Steel |
| Application | Electric Meter Shell, Terminal Block, Power Distribution Box Fixing |
1.Integrated three-in-one pre-crimped integrated structure: Screw, flat washer and spring washer are preassembled together to save manual washer mounting work during component installation.
2.Elastic anti-loose double-washer matching design: Spring washer offers lasting elastic preload to counter vibration and avoid screw loose for long-running electric meter equipment.
3.Abundant diversified head and drive type selection: Multiple drive styles fit different screwdriver tools to adapt diversified meter casing and terminal block mounting structures.
4.Two alternative high-performance raw material grades: Stainless steel for damp outdoor anti-rust needs and zinc-plated steel for economical indoor bulk production procurement.
5.Full range of standard metric dimension coverage: From small M5 to large M10 plus short/extra-long lengths to fulfill all mainstream meter assembly specification requirements.
Greatly boost factory assembly production efficiency
Pre-finished triple combination design removes separate gasket fitting step to cut labor cost for automatic meter production assembly lines.
Dual washer structure improves overall fastening stability
Flat washer uniformly spreads compression force while spring washer provides elasticity to enhance long-term anti-vibration connection performance.
Flexible personalized OEM & ODM customization service
We adjust thread length, head contour and plating treatment strictly based on clients’ original meter design drawings and physical samples.
Excellent anti-corrosion surface protection treatment
Standard zinc plating and stainless steel passivation effectively resist moisture and corrosive gas inside electrical cabinets all year round.
Spot inventory for mainstream regular specifications
Core common M5/M6/M8/M10 sizes are stocked in warehouse to realize quick delivery of small sample orders and urgent bulk purchase orders.
Global power equipment standard compliant design
Mechanical performance and dimensional parameters meet international fastener codes for matching various domestic and imported electric meter products.


