What is the difference between JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set and Class 8.8 bolts?

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set and Class 8.8 bolts are both common fasteners in the global steel construction industry. However, JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set is professionally engineered and strictly manufactured for high-standard friction-type steel structure connections. Most structural designers and international procurement buyers often struggle to distinguish these two fastener products during project bidding and material selection. Improper fastener selection will directly cause connection slip, structural deformation, and long-term safety hazards in large steel structure projects.

Raw Material & Production Standard Difference

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set adopts high-quality medium carbon steel raw materials that fully comply with JIS B1186 national industrial standard. The raw material strictly controls carbon content, manganese content and impurity elements to ensure stable mechanical performance after quenching and tempering heat treatment. The bolt grade is F10T and the matched nut grade is F10, which are professionally calibrated for friction-type high-preload connection systems. All size tolerances, thread precision and mechanical indicators are implemented in full accordance with JIS B1186 standard specifications.

Class 8.8 ordinary structural bolts adopt general medium carbon steel raw materials with loose material standards and simplified heat treatment procedures. Class 8.8 bolts only meet conventional bearing connection requirements and do not have special material parameter restrictions for anti-slip friction joints. Therefore, Class 8.8 bolts cannot replace JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set for key structural friction connection nodes.

Connection Working Principle

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set relies on the high friction force between steel plate contact surfaces to transfer structural load. After precise high preload tightening, this bolt set can maintain lasting and stable clamping force, effectively avoiding bolt displacement and slip under long-term cyclic load, mechanical vibration and temperature fluctuation.

Class 8.8 bolts mainly transfer load through bolt body shear force and bearing pressure. Class 8.8 bolts rely on the bolt itself to bear structural stress, which is easy to produce micro-displacement under repeated heavy loads. The anti-slip stability of Class 8.8 bolts cannot meet the safety design standard of high-end steel structure engineering.

Strength Grade & Heat Treatment Performance

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set undergoes integral quenching and high-temperature tempering treatment, with stable tensile strength, yield strength and fatigue resistance. The whole set of bolts and nuts adopts supporting heat treatment process to ensure the mechanical matching degree reaches 100% standard compliance.

Class 8.8 bolts adopt conventional quenching and tempering process with lower overall strength and poor fatigue resistance. Under continuous heavy load and vibration environment, Class 8.8 bolts are prone to loose connection and fatigue failure.

Application Scope Difference

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set is widely used in global high-standard steel structure projects, including large-span steel bridges, high-rise building steel frames, industrial factory steel structures, power engineering supports, municipal infrastructure and overseas key engineering projects. This professional bolt set is the designated fastener for friction-type rigid connection nodes in international steel structure design codes.

Class 8.8 bolts are mostly used for general mechanical equipment assembly, small steel brackets, ordinary steel structure auxiliary connections and low-load non-key nodes. Class 8.8 bolts have cost advantages in conventional scenarios, but cannot be used for main force-bearing friction connection positions.

Why Choose Ningbo Gangtong Zheli Fastener Co., Ltd

Ningbo Gangtong Zheli Fastener Co., Ltd is a professional manufacturer specializing in the production and export of JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set. The company strictly implements JIS B1186 standard material procurement and production management, and all raw materials of this bolt set are selected from qualified large-scale steel mills with complete material certificates and traceability reports.

Ningbo Gangtong Zheli Fastener Co., Ltd is equipped with fully automatic production equipment, professional heat treatment workshop and independent third-level testing laboratory. Every batch of JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set will undergo tensile test, yield test, hardness test, torsion test and coating thickness detection before delivery. Complete MTR material test reports, factory inspection certificates and batch qualification documents can be provided to meet international project acceptance and customer audit requirements.

The company has long-term stable export experience, serving global steel structure engineering enterprises, and can provide customized HDG hot dip galvanizing, black oxide and other surface treatments for JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set.

Professional Packaging & Shipment Standard

JIS B1186 Heavy Hex Friction Grip High Strength Bolt Set adopts exclusive international export-grade packaging solution formulated by Ningbo Gangtong Zheli Fastener Co., Ltd. All finished products are cleaned, derusted and sorted manually before packaging to ensure no impurities, no burrs and no surface defects.

The finished bolts are packed in thickened moisture-proof export cartons with fixed quantitative packaging standards. Each carton is attached with a detailed product label, marking standard, size, grade, quantity, net weight, batch number and production date. All cartons are neatly stacked on fumigated wooden pallets, fixed with tension straps, and fully wrapped with waterproof and dust-proof stretch film to prevent moisture, rust, collision and extrusion during long-distance sea transportation.