What types of stainless steel screws do you manufacture?

StainGrip specializes in the production of high-quality SS304, SS305, and SS316 stainless steel screws. Our core product range includes roofing screws, decking screws, and wood screws, engineered for superior durability and corrosion resistance.

Are you a trading company or a manufacturer?

StainGrip is a direct manufacturer specialized in stainless steel fasteners. We have full control over the production process, ensuring consistent quality and competitive factory-direct pricing for our global partners.

Do you offer fasteners for B2B and industrial clients?

Yes, we provide comprehensive OEM/ODM services tailored for B2B and industrial clients, including customized packaging and head marking to align with your brand identity and technical specifications.

What are the differences between 304, 305, and 316 stainless steel screws?

Grade 304 is for general-purpose corrosion resistance. Grade 305 features a lower work-hardening rate, ideal for high-volume decking installations. Grade 316 offers maximum protection in marine or high-chloride environments.

What is the typical lead time for bulk orders to the US or Europe?

For standard stainless steel screws, our lead time is typically 30-45 days. We also offer expedited shipping and flexible logistics solutions for urgent wholesale orders to ensure project timelines are met.

410/304/316 Stainless Steel Heavy-Duty Sandwich Panel Screws

Stainless steel 410, 304 and 316

Material

Size

Length

Coating

StainGrip® 304 / 316 Stainless Steel Heavy-Duty Sandwich Panel Screws (available in both solid austenitic stainless and high-performance Bi-Metal constructions) are specialized structural fasteners engineered for fixing insulated sandwich panels (PIR, PUR, EPS, Rockwool) directly onto steel purlins or timber substructures. Featuring a unique dual-thread design and pre-assembled weatherproofing EPDM bonded washers, these fasteners provide airtight, watertight seals and secure structural engagement across roof and wall cladding systems.

Key Features & Technical Benefits

Dual-Thread Technology (Upper Support & Primary Fastening Threads):
- Upper Retaining Thread (Larger Diameter): Situated directly under the hex head, this thread engages the outer metal skin of the insulated panel, supporting the face sheet and preventing panel crushing, sheet dimpling, or thermal deformation.
- Primary Lower Thread: Drives into the underlying structural purlin or wood support, securing high pull-out resistance.
Pre-Assembled Stainless Steel EPDM Bonded Sealing Washer: Fitted with an oversized, weather-resistant EPDM rubber washer vulcanized to a stainless steel backing disc, ensuring a long-lasting, watertight and airtight seal against severe rain, wind-driven moisture, and thermal expansion.
304 & 316 Stainless Steel Construction: Formulated with high nickel and chromium alloys (plus molybdenum in SS316) to provide maximum protection against rust, industrial pollution, outdoor weathering, and harsh coastal salt spray.
Available Bi-Metal High-Drilling Options: For installation directly into heavy structural steel purlins (e.g., up to 6mm or 12mm thickness), bi-metal variants feature a precision welded, heat-treated alloy steel drill point fused to the SS304/SS316 body.
Hex Washer Head Drive: Hex flange design allows positive socket driver engagement, preventing socket slipping and ensuring controlled compression of the EPDM washer without over-tightening.

Technical Specifications

Feature	Specification
Material Grade	SS304 (A2) / SS316 (A4) Marine Grade Stainless Steel (or Bi-Metal)
Head Style	Hex Washer Head
Washer Type	Pre-Assembled Stainless Steel EPDM Bonded Sealing Washer
Thread Type	Dual Thread (Upper Support Thread + Lower Structural Tapping Thread)
Point Type	Self-Drilling Tek Point / Bi-Metal Tek 3 or Tek 5 Point
Application	Insulated Sandwich Panels (Roofing & Wall Cladding), Cold Storage Facilities, Industrial Metal Buildings

Stainless Steel Grades:

o 304 / 18-8 Stainless Steel: Excellent corrosion resistance, ideal for general applications.

o 305 Stainless Steel: High nickel content, non-magnetic, ideal for cold forming and deep drawing.

o 316 Stainless Steel: Marine-grade, superior resistance to salt water and chemicals.

Applicable Standards:

o Dimensional: ASME B18.6.3 / ASME B18.2.1 / ANSI

o Material / Physical: ASTM F593 (Group 1: 304/305, Group 2: 316) / ASTM A240

Certifications: MTR (Material Test Report) / Mill Certs available upon request.

Fast Dispatch for Stocked Items: Ready-to-ship inventory available for quick order dispatch.
Factory-Direct Bulk Production: Competitive direct-from-factory lead times for wholesale and custom orders.
Flexible International Shipping: Comprehensive shipping options including FOB, CIF, and DDP (Door-to-Door with duties paid).
Tracking & Logistics: Full shipment tracking provided from factory loading to final delivery.

We offer full OEM/ODM manufacturing to meet your specific application needs.

Head Marking & Design: Custom head logo, drive type, and head shape.
Dimensions & Tolerances: Custom sizes according to ASME standards or customer drawings.
Head Painting & Coating: Head color matching, passivation, and specialty finishes.
Private Label Packaging: Custom inner/outer box design, polybags, and barcode labeling.
Samples: Custom samples and initial inspection reports available before full production.

Flexible custom packaging solutions available for both wholesale and retail markets:

Multiple Packaging Options: From small polybags and small inner boxes to industrial bulk packing.
Custom Printing & Logo: Custom box design, printed logos, and brand artwork.
Labeling & Barcodes: Private labels, UPC/EAN barcodes, part numbers, and shipping marks.

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Get a Fast Quote Today

Looking for standard or custom stainless steel screws? Contact our engineering team for factory-direct pricing, MTR reports, and fast shipping. We will get back to you within 1 business day upon receiving your inquiry.