Allen Bolts
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Sunmach specializes in manufacturing premium Duplex Allen Bolts, custom-engineered to provide exceptionally high-strength, vibration-resistant, and space-saving fastening solutions for critical industrial and marine assemblies. Featuring a cylindrical head and a recessed hexagonal drive socket, these premium fasteners sit flush with or below mating component surfaces, allowing for clean, streamlined assemblies in tight, restricted spaces where bulky standard hexagonal head fasteners cannot fit. By distributing heavy clamping preloads uniformly across the joint, they prevent localized material crushing, thread stripping, and joint relaxation under severe mechanical loads. These premium Duplex Allen Bolts are specifically engineered to perform reliably in the world's most aggressive marine and chemical process environments. Sourced from premium global mills, the balanced dual-phase metal structure combines outstanding resistance to saltwater crevice corrosion with nearly double the yield strength of traditional stainless steel. Backed by rigorous quality validation and delivered with complete batch traceability, Sunmach ensures zero-failure performance and reliable pressure-boundary sealing over long-term operational lifecycles.
Duplex Allen Bolts
Sunmach manufactures premium Duplex Allen Bolts engineered for applications demanding exceptional corrosion resistance combined with high strength in demanding industrial environments. As a leading global supplier with ISO 9001:2015 certification, we deliver Duplex Allen Bolts that exceed international standards and provide superior performance in critical applications.
MANUFACTURING EXCELLENCE: With 13+ years of specialized manufacturing experience, Sunmach combines advanced hot forming technology with precision manufacturing to deliver Duplex Allen Bolts with superior dimensional accuracy, tight tolerances per ISO 4762, consistent mechanical properties, complete material integrity, and full traceability and documentation for every fastener produced.
MATERIAL SPECIFICATIONS: Our Duplex Allen Bolts are manufactured from premium duplex stainless steel including Duplex S31803 (superior corrosion resistance with PREN 35+), Duplex S32205 (enhanced mechanical properties), and Super Duplex S32750 (highest performance grade with PREN 42+). Each grade is precisely selected for specific application requirements, ensuring optimal performance and longevity in service.
CRITICAL APPLICATIONS
Duplex Allen Bolts are ideal for Aerospace applications (critical fastening), Oil & gas, Chemical processing (corrosive environments), Marine engineering (saltwater exposure), Petrochemical facilities, Power generation, and Pharmaceutical equipment requiring the highest standards of reliability and corrosion resistance.
QUALITY ASSURANCE
Every Duplex Allen Bolt undergoes chemical composition verification, mechanical property testing, dimensional inspection (CMM certified), surface quality verification, and 100% traceability with complete certification documentation.
Sizes
| Metric : | M6 to M76 |
| Imperial : | 1/4" to 3" |
| MOQ : | 1 Piece & Above |
| Certification : | EN 10204 3.1, EN 10204 3.2 (On Demand) |
Specification
| Bolt | DIN | ISO | ANSI | IS |
|---|---|---|---|---|
| Allen Bolts | 912 | 4762 | B18.3 | - |
Frequently Asked Questions
Common questions about Sunmach Duplex Allen Bolts
Duplex Allen Bolts have a much smaller head diameter than a standard hex bolt of the same thread size, allowing them to be placed closer together or recessed inside counterbored holes for compact industrial designs.
ISO 4762 and DIN 912 are nearly identical and can generally be used interchangeably, though minor variations exist in dimensional tolerances, head height limits, and thread lengths for specific non-standard metric sizes.
Upgrade to super duplex S32750 alloys for highly aggressive chemical environments or hot seawater. Super duplex S32750 features a higher pitting resistance equivalent number (PREN) of 42+, withstanding much higher chloride concentrations.