Square Taper Washer

Square Taper Washer — Channel & I-Beam Taper Washer | DIN 434 / DIN 435 | Steel Structure Connection

Square taper washers are specialized structural washers with a tapered (wedge-shaped) profile on one face, designed to compensate for the inherent slope of channel flanges (I-beams, U-channels, and H-beams). Manufactured to DIN 434 and DIN 435 standards, our square taper washers ensure that the bolted connection achieves even clamping force across the entire bearing surface by eliminating the angular misalignment caused by tapered flanges. Essential components in steel structure construction, available in sizes M12 to M36 with hot-dip galvanized coating as standard.

Material & Specifications

Size Range	M12 to M36 / 1/2″ to 1-1/2″ (bolt diameter)
Standard	DIN 434 (Square Taper Washers for U-Profiles), DIN 435 (Square Taper Washers for I-Profiles), GB/T 1230, EN 14399-6
Material	Carbon Steel (S235JR / Q235B), High-Strength Steel (S355 / Q345B), Weathering Steel (Corten A/B), Stainless Steel 304/316
Surface / Coating	Hot-Dip Galvanized (HDG) — Standard for structural applications, Dacromet for high-strength bolts, Multi-Element Alloy Co-Permeation, Electroplated Zinc, Weathering Steel (uncoated)
Taper / Slope	4% (standard for I-beam flanges), 6%, 8%, 10% (for various channel profiles)
Types	Square Taper for U-Channels (DIN 434), Square Taper for I-Beams (DIN 435), Rectangular Taper, Custom Slope per Profile

Surface Treatment & Zinc Coating Quality

At BoltNutsPlus, we understand that surface treatment is critical to fastener longevity and performance. Our washers undergo rigorous coating processes to ensure maximum corrosion resistance and durability. We offer five premium coating options, each tested to international standards:

• Hot-Dip Galvanizing (HDG) — Thick zinc layer (50-120μm) providing superior long-term corrosion protection for outdoor, marine, and industrial environments. Compliant with ISO 1461 / ASTM A153 standards. Salt spray resistance: 500-1,000+ hours. HDG washers are ideal for structural steel assemblies exposed to harsh weather.
• Electroplated Zinc Blue-White (Zn Blue/White) — Bright, clean silver-blue appearance with 5-15μm zinc layer. Cr3+ passivation technology, fully RoHS compliant. Ideal for indoor machinery, electronics, and general-purpose applications requiring aesthetic appeal and moderate corrosion resistance.
• Color Zinc / Yellow Zinc (Iridescent Passivation) — Multi-colored iridescent passivation film offering enhanced corrosion resistance (100-200 hours salt spray) with a distinctive golden finish. Widely preferred in automotive, agricultural equipment, and construction machinery sectors for its balanced protection and visual appeal.
• Dacromet Coating — Advanced water-based zinc-chromium coating technology with NO hydrogen embrittlement risk. Provides 1,000+ hours salt spray resistance, making it the preferred choice for high-strength fasteners in extreme environments. Environmentally friendly (no heavy metal discharge), RoHS/ELV compliant, ideal for automotive and wind energy applications.
• Multi-Element Alloy Co-Permeation — Zinc-aluminum-rare earth alloy layer offering 2-3x the corrosion resistance of traditional galvanizing. Features self-healing properties at scratch points, ensuring long-term protection even in damaged areas. Ideal for critical infrastructure, power transmission towers, coastal projects, and marine installations.

Key Features

• Tapered profile precisely matches channel flange slope ensures 100% surface contact and even bolt loading
• Eliminates bending stress in bolts caused by angular misalignment — prevents premature bolt failure in structural connections
• Required by structural steel codes (EN 1090, AISC 360) for bolted connections on tapered flange surfaces
• Hot-dip galvanized to ISO 1461 as standard, providing decades of corrosion protection in exposed steel structures
• Available in multiple taper slopes (4%, 6%, 8%, 10%) to match different standard channel and I-beam profiles
• Compatible with high-strength structural bolts (Grade 8.8, 10.9, ASTM A325, A490) for preloaded connections

Applications

• Steel structure buildings — beam-to-column connections on I-beam and H-beam flanges
• Industrial plant and warehouse construction with extensive structural steel framing
• Bridge construction and highway infrastructure projects requiring code-compliant connections
• Crane runway beams, monorails, and material handling system support structures
• Pipe rack and cable tray support steelwork in petrochemical and power generation facilities
• Transmission line towers and communication tower structural connections

Why Choose BoltNutsPlus?

• ISO 9001:2015 Certified Manufacturing — consistent quality you can trust on every batch
• 15+ Years of Export Experience — serving 40+ countries across 6 continents
• Full Traceability — material certificates (EN 10204 3.1) and comprehensive test reports included
• Custom Packaging & OEM/ODM — your brand identity, your specifications, our precision manufacturing
• Third-Party SGS / Bureau Veritas Inspection Available upon request
• 24-Hour Quote Response — same-day reply for urgent requirements; standard 24-hour turnaround