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Self Tapping Screw

GB 15856.4 Hex Washer Head Carbon Steel Self-Tapping Fasteners with EPDM Seals for Metal Roofing & Sheet Assembly

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GB 15856.4 Hex Washer Head Carbon Steel Self-Tapping Fasteners with EPDM Seals for Metal Roofing & Sheet Assembly

Brand Name:	YongBiao
Model Number:	GB15856.4
MOQ:	20000
Price:	Negotiation
Packaging Details:	Carton Box/Pallet/Customized
Payment Terms:	T/T

Detail Information

Product Description

Detail Information

Place of Origin:

ZheJiang China

Certification:

ISO9001,IATF16949

Color:

Zinc Plated,Silvery Or Black,Natural,red Blue Black Orange Green Yellow Silver Gold Purple Pink,Sliver

Grade:

4.8,B8,5.6,10.9,8.8

Surface Treatment:

Heat Treating,Black Zinc,Polished,Zinc Plated,Anodized

Length:

13--152mm,4mm 6mm 8mm 10mm 12mm 14mm 20mm 30mm 40mm,3mm-60mm,10-50mm,16mm-120mm

Sample:

Available,5-8 PCS Samples FREE,free,Avaliable (shipping Costs Needed)

Package:

PE Bag /carton Box Or Customized,Cartons&pallets Or According To Customer's Requirement.,Carbon Box+plastic Bags

Supply Ability:

500Tons/month

Highlight:

Hex Washer Head Self-Tapping Screws

Carbon Steel Self-Tapping Fasteners

EPDM Sealed Roofing Self-Tapping Screws

Product Description

Product Overview

GB 15856.4 Hex Head Self-Tapping Screws with EPDM Washers are high-performance industrial fasteners engineered 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 is critical.

Key Features

Strict Compliance with GB 15856.4 Standard

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.

Superior EPDM Weatherproof Sealing

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.

High-Strength Carbon Steel & Durable Galvanizing

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.

External Hex Head Design for High Torque Drive

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.

Integrated Flat Bearing & Load Distribution

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.

Dimensional Specifications

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

Applications

Metal Roofing & Wall Cladding: Secure attachment of corrugated steel sheets and sandwich panels to metal or timber purlins.
Steel Structure Construction: Industrial workshops, warehouses, and prefabricated steel frame buildings.
HVAC & Ductwork: Assembly of heating, ventilation, and air-conditioning units and metal ducting.
Automotive & Equipment Enclosures: Sheet metal housings, electrical cabinets, and chassis assembly.

Packaging & Logistics Options

Standard Export Packaging: Bulk in 20/25 kg cartons plus fumigated wooden pallets.
Small Box Packaging: Customized polybags or small inner boxes with custom barcode labeling.
Port of Loading: Ningbo / Shanghai / Lianyungang, China.
Trade Terms: FOB, CFR, CIF, DDP, DAP.

Frequently Asked Questions

Q1: What is the main difference between GB 96.2 and standard GB 97.1 flat washers?

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.

Q2: Can you provide customized salt spray testing for higher corrosion protection?

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).

Q3: Are samples available before placing a bulk order?

A: Yes, standard size samples are provided free of charge for quality verification and fit testing. Shipping fees apply.

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Products Details

Home > Products >

Self Tapping Screw

GB 15856.4 Hex Washer Head Carbon Steel Self-Tapping Fasteners with EPDM Seals for Metal Roofing & Sheet Assembly

All Category

Pan Head Screw

Bugle Head Screw

Self Tapping Screw

Self Drilling Screw

Stainless Steel Screw

Screw Kit

Concrete Anchor Bolt

Hex Head Bolt

Allen Head Bolt

Machine Bolt

Expansion Anchor Bolt

Hex Head Nut

Spring Lock Washer

Waterproof Cable Gland

Precision Turned Components

Plastic Bolt

GB 15856.4 Hex Washer Head Carbon Steel Self-Tapping Fasteners with EPDM Seals for Metal Roofing & Sheet Assembly

Brand Name:	YongBiao
Model Number:	GB15856.4
MOQ:	20000
Price:	Negotiation
Packaging Details:	Carton Box/Pallet/Customized
Payment Terms:	T/T

Detail Information

Product Description

Detail Information

Place of Origin:

ZheJiang China

Brand Name:

YongBiao

Certification:

ISO9001,IATF16949

Model Number:

GB15856.4

Color:

Zinc Plated,Silvery Or Black,Natural,red Blue Black Orange Green Yellow Silver Gold Purple Pink,Sliver

Grade:

4.8,B8,5.6,10.9,8.8

Surface Treatment:

Heat Treating,Black Zinc,Polished,Zinc Plated,Anodized

Length:

13--152mm,4mm 6mm 8mm 10mm 12mm 14mm 20mm 30mm 40mm,3mm-60mm,10-50mm,16mm-120mm

Sample:

Available,5-8 PCS Samples FREE,free,Avaliable (shipping Costs Needed)

Package:

PE Bag /carton Box Or Customized,Cartons&pallets Or According To Customer's Requirement.,Carbon Box+plastic Bags

Minimum Order Quantity:

20000

Price:

Negotiation

Packaging Details:

Carton Box/Pallet/Customized

Delivery Time:

7-25Days

Payment Terms:

T/T

Supply Ability:

500Tons/month

Highlight:

Hex Washer Head Self-Tapping Screws

Carbon Steel Self-Tapping Fasteners

EPDM Sealed Roofing Self-Tapping Screws

Product Description

Product Overview

Key Features

Strict Compliance with GB 15856.4 Standard

Superior EPDM Weatherproof Sealing

High-Strength Carbon Steel & Durable Galvanizing

External Hex Head Design for High Torque Drive

Integrated Flat Bearing & Load Distribution

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.

Dimensional Specifications

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

Applications

Metal Roofing & Wall Cladding: Secure attachment of corrugated steel sheets and sandwich panels to metal or timber purlins.
Steel Structure Construction: Industrial workshops, warehouses, and prefabricated steel frame buildings.
HVAC & Ductwork: Assembly of heating, ventilation, and air-conditioning units and metal ducting.
Automotive & Equipment Enclosures: Sheet metal housings, electrical cabinets, and chassis assembly.

Packaging & Logistics Options

Standard Export Packaging: Bulk in 20/25 kg cartons plus fumigated wooden pallets.
Small Box Packaging: Customized polybags or small inner boxes with custom barcode labeling.
Port of Loading: Ningbo / Shanghai / Lianyungang, China.
Trade Terms: FOB, CFR, CIF, DDP, DAP.

Frequently Asked Questions

Q1: What is the main difference between GB 96.2 and standard GB 97.1 flat washers?

Q2: Can you provide customized salt spray testing for higher corrosion protection?

Q3: Are samples available before placing a bulk order?

A: Yes, standard size samples are provided free of charge for quality verification and fit testing. Shipping fees apply.

Tags: