I. Application Fields

Black EPDM rubber washers are designed for outdoor color steel sheds, factory roofs and outdoor fences with reliable waterproof and anti-seepage performance. Transparent PVC washers are mostly applied to indoor light steel keels, door & window subframes and electromechanical sheet metal assembly.

One screw fits both indoor and outdoor thin plate fastening scenarios, serving as a universal fastener for civil steel structures and home decoration supporting projects. Large volumes are exported year-round to hardware and building material markets across Southeast Asia and the Middle East.

Equipped with an integrally formed drill point to eliminate pre-drilling, it greatly improves construction efficiency.

II. Raw Materials & Production Processes

Made of premium SWRCH22A carbon steel with quenching reinforcement on drill points, delivering sharp drilling performance and resisting tip chipping and tail breakage.

The complete production workflow covers eleven procedures: raw material rough drawing, annealing, phosphating, fine drawing, cold heading forming, drill point shaping, thread rolling, thermal refining treatment, blue-white zinc electroplating, washer assembly and packaging.

The neat hex flange surface ensures even force distribution and no slipping during tightening with socket wrenches; full uniform threads create tight interlock with substrates. The two types of washers are separately matched for outdoor and indoor working conditions, firmly bonded without falling off.

III. Core Product Advantages

Dual Optional Washers for Different Scenarios

Black EPDM rubber washers feature UV resistance and anti-aging properties to provide reliable sealing and waterproof performance under outdoor rain exposure. Transparent PVC washers are lightweight with outstanding cost performance for dry indoor environments.

Full Continuous Threads Deliver Powerful Clamping Force

Full-length threads tightly grip iron sheets and steel keels, preventing loosening and falling off under strong wind and vibration.

Dense Blue-White Zinc Coating

The compact blue-white zinc plating isolates moisture oxidation for general indoor and outdoor use. Dacromet coating can be upgraded for coastal high-humidity and corrosive environments.

IV. Quality Control, Warehousing & Supporting Services

All sizes are permanently stocked. Standard orders can be dispatched within 48 hours, and we accept small trial orders as well as full-container export orders.

Pre-delivery sampling inspection covers drill point hardness, flange flatness, washer bonding strength and coating quality to screen out defective products including bent screws, detached washers and flawed coatings.

Complete fastener sets bundled with nylon cap painted self-drilling screws and extended self-drilling screws for sandwich panels are available for stock preparation. Custom non-standard products with special lengths and coatings can be produced against customer samples, with stable production capacity to support long-term supply for all types of construction projects.