Hex Head Bolt
Hex head bolts feature a hexagonal head design for easy installation with a wrench or socket. They provide stable fastening and are widely used in machinery, steel structures, construction projects, automotive applications, and industrial assembly.
Hot Dip Galvanized Railway Fasteners
Railway fastening systems are vital safety components that secure rails to sleepers and connect rail segments, enduring strong vibrations while maintaining standard track gauge. Exposed to harsh outdoor conditions, fasteners face severe corrosion. Our hot dip galvanized (HDG) fasteners with a zinc coating over 40μm provide durable anti-rust performance and reduce maintenance work. Hotop supplies standard-compliant HDG rail fasteners including bolts, screws, and matched accessories per UIC, AREMA, DIN, and GB.
Stainless Steel Hex Bolts (SS304 / SS316) | A4-80 Heavy Duty Hexagon Head Fasteners
Stainless steel hex head bolts in SS304 and SS316 comply with DIN933/DIN931 standards. Passivated surface avoids thread seizing, with complete custom sizes. Excellent corrosion resistance fits coastal, chemical and marine projects. Factory in Handan offers strict testing, customized packing and stable shipping to Southeast Asia, with MTC certification provided.
SS304 / SS316 Hex Head Bolts
Stainless steel hex head bolts comply with DIN933 full thread & DIN931 half thread standards, available in SS304 A2-70 and marine SS316 A4-80. Passivated finish avoids thread galling, 6g precise metric threads. Factory in Handan holds abundant standard stock with fast delivery, full quality inspection and MTC certificates, widely used for coastal solar, chemical and municipal projects in Southeast Asia.
Made-to-Print Custom HDG Fasteners & Structural Hardware
Custom made-to-print HDG fasteners are tailor-produced per customer drawings. Engineers reserve dimensional allowance before hot dip galvanizing to avoid thread jamming and tolerance deviation. We prevent hydrogen embrittlement and offer full in-house forging, CNC machining & FAI inspection. Covering anchor bolts, U-bolts, clevis pins etc., with moisture-proof customized export packaging for infrastructure and heavy machinery.
Heavy-Duty HDG Fasteners for Agricultural Machinery and Farm Infrastructure
HDG agricultural fasteners feature thick zinc alloy coating resistant to fertilizer, manure abrasion and outdoor moisture. Matching nuts are overtapped for smooth assembly. Includes carriage bolts, square nuts, U-bolts and high-strength hex bolts, widely used in greenhouses, livestock pens, irrigation and farm machinery OEMs. Factory strict QC and moisture-proof export packaging, also supports custom drawing production.
High-Strength HDG Structural Bridge Bolts
HDG structural bridge bolts comply with ASTM A325 and EN14399 standards, and are not applicable to A490 due to the risk of hydrogen embrittlement. They are equipped with heavy hex heads, matched overtapped nuts, and hardened washers, and have passed ROCAP, tensile, and coating thickness tests. Complete MTR traceability is provided, and the thick zinc coating resists salt and de-icing salt. They are packed in iron kegs for heavy infrastructure such as highway and railway bridges. Alternative anti-corrosion coatings are available for high-strength A490 projects.
High-Tensile HDG Tower & Step Bolts for Transmission Structures
HDG tower bolts comply with ASTM A394 and DIN7990, with short threads to place shear plane on solid bolt shank for better wind resistance. Step bolts adopt centrifugal process for smooth zinc coating to protect climbing workers. Supporting overtapped matched nuts, thick HDG coating delivers over 30 years anti-corrosion performance. Widely used for power transmission towers, 5G monopoles and substation steel frames, packed moisture-proof for export.
High-Tensile HDG Tower Bolts for Transmission Structures
HDG tower bolts comply with ASTM A394 and DIN7990 with short threads to place shear plane on solid shank for higher wind resistance. Over 50μm thick matte zinc alloy coating offers over 30 years anti-corrosion. Supporting overtapped matched nuts for easy high-altitude installation. Step bolts adopt centrifugal process for smooth coating without sharp burrs. Widely used for power transmission towers, 5G telecom poles, packed moisture-proof in cartons or iron kegs for export.
High-Strength HDG Flange Bolts for Solar Racking (DIN 6921)
DIN6921 HDG flange bolts integrate an integral washer to cut solar installation time by 25%, with smooth or anti-vibration serrated bottom options. Zinc coating ≥45μm supports 25-year outdoor anti-corrosion, compatible with aluminum solar rails without galvanic corrosion. Matched overtapped DIN6923 flange nuts ensure smooth assembly. Centrifugal treatment protects serrations; moisture-proof carton & pallet export packaging, custom oversized flanges available.