Full Thread Hexagon Head Bolt

Full Thread Hexagon Head Bolt — Product Introduction

Full thread hexagon head bolt is a fastener with a hexagonal head and continuous thread along the full length of the shank. Its current national standard is GB/T 5783 (the latest version is GB/T 5783-2025, implemented on February 1, 2026). It is suitable for steel and stainless steel bolts with thread specifications M1.6–M64, coarse threads, and product grades A and B. Property classes include 4.8, 5.6, 8.8, 10.9, 12.9, and stainless steel A2-50, A2-70, A4-70, A4-80, etc. Except for being manufactured as full thread and having a preferred nominal length of up to 200 mm, this product is identical to GB/T 5782. The full thread design allows it to engage with a nut at any position, making it suitable for connections requiring a wide range of clamping position adjustment.

I. Product Features

• Full thread continuous structure: The thread extends along the full length of the shank without a plain shank section. It can be screwed into a nut or threaded hole at any position, providing flexible clamping position adjustment, especially suitable for assembly scenarios requiring large-range adjustment.

• Hexagon head drive: The head is a standard hexagon, which can be operated with an open-end wrench, box-end wrench, socket wrench, or adjustable wrench. It is convenient to apply force and can withstand large tightening torque.

• Product grades A and B: Grade A is used for bolts with d=1.6 mm–24 mm and l≤10d or l≤150 mm (whichever is smaller); Grade B is used for bolts with d>24 mm or l>10d or l>150 mm (whichever is smaller). The precision grades cover different specification requirements.

• Complete specifications and materials: Thread specifications range from M1.6 to M64, with a wide range of nominal lengths. Materials include carbon steel (such as 10B21, 35K, 45#), alloy steel (such as 35CrMo, AG35ACr), and stainless steel (304, 316), etc.

• Various surface treatments: Carbon steel and alloy steel parts can be treated with zinc plating (blue-white zinc, color zinc), blackening, Dacromet, etc.; stainless steel parts are usually delivered in natural color or passivated.

• High thread precision: The thread tolerance is 6g (Grade A) or 8g (Grade B), ensuring tight engagement and stable connection.

II. Product Advantages

• Flexible adjustment of clamping position: The full thread structure allows the nut to be locked at any position without being limited by a plain shank section. It is suitable for occasions requiring frequent adjustment of the clamping position or connecting workpieces of different thicknesses.

• Adjustment without the need for washers: The full thread design can be directly screwed into a threaded hole, simplifying assembly and reducing dependence on additional washers.

• Strong load-bearing capacity: Using high-strength materials such as 8.8, 10.9, and 12.9, the tensile strength of the carbon steel version can reach over 700 MPa, and the alloy steel version can meet higher load requirements.

• Reliable anti-loosening: Combined with thread locking adhesive or self-locking nuts, it can effectively prevent loosening under vibration conditions, making it suitable for dynamic load environments.

• Good standardized interchangeability: As a national standard product, it has uniform dimensions and standardized marking (such as "GB/T 5783-2025 M12×50-8.8-Zn"), and products from different suppliers can be used interchangeably.

• Repeatable disassembly and assembly: The thread structure is complete and can be repeatedly screwed in and out without damaging the thread, facilitating maintenance and component replacement.

III. Scope of Application

• Mechanical equipment manufacturing and assembly: Fixed connections of parts for machine tools, pumps and valves, compressors, reducers, and other equipment.

• Construction engineering: Installation and fastening of steel structure components, curtain wall brackets, and pipe supports.

• Automotive and transportation: Connection and fixation of automobile chassis, engine components, and vehicle modifications.

• Power and energy equipment: Installation and maintenance of power transmission and transformation equipment, generators, transformers, etc.

• Heavy tools and molds: Assembly of components for large molds, lifting equipment, and engineering machinery.

• General industrial maintenance: Fastening needs during daily maintenance and component replacement of various equipment.