| Brand Name: | YongBiao |
| Model Number: | GB15856.4 |
| MOQ: | 20000 |
| Payment Terms: | T/T |
GB 15856.4 zinc plated carbon steel hex head self-tapping screws with EPDM bonded washers — engineered for leakproof metal roofing, cladding, and heavy-duty steel structure fastening.
GB 15856.4 hex head self-tapping screws with EPDM washers are high-performance industrial fasteners designed specifically for heavy-duty metal joining, roofing, and cladding applications. Manufactured from premium carbon steel and protected by standard electro-zinc or hot-dip galvanizing, these screws deliver outstanding mechanical strength, rapid installation, and long-lasting corrosion resistance.
The integrated EPDM bonded washer creates a tight, weatherproof compression seal under the hex head, making these screws the premier choice for exterior steel structures, metal roofing sheets, and industrial wall cladding where zero-leakage performance is critical.
Precision-engineered to satisfy national standard GB 15856.4 (identical to ISO/DIN international self-tapping screw specifications), ensuring consistent thread pitch, head dimensions, and reliable mechanical properties for global structural projects.
Outfitted with a high-grade EPDM (Ethylene Propylene Diene Monomer) rubber washer bonded to a metal backing. It maintains excellent elasticity and UV resistance under extreme temperature fluctuations, effectively locking out moisture and preventing water seepage around fastener holes.
Built from hardened carbon steel for maximum tensile, shear, and torsional resistance during high-speed power tool driving. The uniform zinc-plated surface finish isolates the base metal from ambient humidity, preventing rust and thermal oxidation.
The external hexagon head profile allows full tool engagement with standard hex sockets or nut setters. This minimizes cam-out risks, permits maximum torque transmission without stripping the drive, and accelerates assembly on construction sites.
The broad washer surface spreads the clamping force over a wider contact area. This prevents over-tightening damage, crushing, or surface cracking on thin sheet metals and coated steel panels.
| D | ST3.5 | ST4.2 | ST4.8 | ST5.5 | ST6.3 |
|---|---|---|---|---|---|
| P | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 |
| a max | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 |
| dc max | 8.3 | 8.8 | 10.5 | 11 | 13.2 |
| dc min | 7.6 | 8.2 | 9.8 | 10 | 12.2 |
| c min | 0.6 | 0.9 | 0.9 | 1 | 1 |
| s max | 5.5 | 7 | 8 | 8 | 10 |
| s min | 5.32 | 6.78 | 7.78 | 7.78 | 9.78 |
| e min | 5.96 | 7.59 | 8.71 | 8.71 | 10.95 |
| k max | 3.45 | 4.25 | 4.25 | 5.45 | 5.45 |
| kw min | 1.55 | 1.9 | 2 | 2.7 | 3.3 |
| r max | 0.5 | 0.6 | 0.7 | 0.8 | 0.9 |
A: GB 96.2 features a significantly larger outer diameter (approximately 3× the nominal thread diameter), making it ideal for soft materials, elongated holes, or high-torque load distribution compared to standard GB 97.1 washers.
A: Yes, we can offer thicker electro-zinc coatings or passivation processes (such as yellow zinc or ROHS-compliant trivalent chromium) to meet specific salt spray resistance requirements (e.g., 48h to 96h).
A: Yes, standard size samples are provided free of charge for quality verification and fit testing. Shipping fees apply.
| Brand Name: | YongBiao |
| Model Number: | GB15856.4 |
| MOQ: | 20000 |
| Payment Terms: | T/T |
GB 15856.4 zinc plated carbon steel hex head self-tapping screws with EPDM bonded washers — engineered for leakproof metal roofing, cladding, and heavy-duty steel structure fastening.
GB 15856.4 hex head self-tapping screws with EPDM washers are high-performance industrial fasteners designed specifically for heavy-duty metal joining, roofing, and cladding applications. Manufactured from premium carbon steel and protected by standard electro-zinc or hot-dip galvanizing, these screws deliver outstanding mechanical strength, rapid installation, and long-lasting corrosion resistance.
The integrated EPDM bonded washer creates a tight, weatherproof compression seal under the hex head, making these screws the premier choice for exterior steel structures, metal roofing sheets, and industrial wall cladding where zero-leakage performance is critical.
Precision-engineered to satisfy national standard GB 15856.4 (identical to ISO/DIN international self-tapping screw specifications), ensuring consistent thread pitch, head dimensions, and reliable mechanical properties for global structural projects.
Outfitted with a high-grade EPDM (Ethylene Propylene Diene Monomer) rubber washer bonded to a metal backing. It maintains excellent elasticity and UV resistance under extreme temperature fluctuations, effectively locking out moisture and preventing water seepage around fastener holes.
Built from hardened carbon steel for maximum tensile, shear, and torsional resistance during high-speed power tool driving. The uniform zinc-plated surface finish isolates the base metal from ambient humidity, preventing rust and thermal oxidation.
The external hexagon head profile allows full tool engagement with standard hex sockets or nut setters. This minimizes cam-out risks, permits maximum torque transmission without stripping the drive, and accelerates assembly on construction sites.
The broad washer surface spreads the clamping force over a wider contact area. This prevents over-tightening damage, crushing, or surface cracking on thin sheet metals and coated steel panels.
| D | ST3.5 | ST4.2 | ST4.8 | ST5.5 | ST6.3 |
|---|---|---|---|---|---|
| P | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 |
| a max | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 |
| dc max | 8.3 | 8.8 | 10.5 | 11 | 13.2 |
| dc min | 7.6 | 8.2 | 9.8 | 10 | 12.2 |
| c min | 0.6 | 0.9 | 0.9 | 1 | 1 |
| s max | 5.5 | 7 | 8 | 8 | 10 |
| s min | 5.32 | 6.78 | 7.78 | 7.78 | 9.78 |
| e min | 5.96 | 7.59 | 8.71 | 8.71 | 10.95 |
| k max | 3.45 | 4.25 | 4.25 | 5.45 | 5.45 |
| kw min | 1.55 | 1.9 | 2 | 2.7 | 3.3 |
| r max | 0.5 | 0.6 | 0.7 | 0.8 | 0.9 |
A: GB 96.2 features a significantly larger outer diameter (approximately 3× the nominal thread diameter), making it ideal for soft materials, elongated holes, or high-torque load distribution compared to standard GB 97.1 washers.
A: Yes, we can offer thicker electro-zinc coatings or passivation processes (such as yellow zinc or ROHS-compliant trivalent chromium) to meet specific salt spray resistance requirements (e.g., 48h to 96h).
A: Yes, standard size samples are provided free of charge for quality verification and fit testing. Shipping fees apply.