High Temperature Heavy Duty Hex Structural Bolts

High Temperature Heavy Duty Hex Structural Bolts belong to full-thread alloy stud fasteners developed for high-temperature, high-pressure industrial working environments. Raw material of this product adopts chromium-molybdenum alloy steel with carbon mass fraction controlled between 0.37% and 0.44%, chromium content 0.80%~1.10% and molybdenum content 0.15%~0.25%. The precise material proportion effectively improves the high-temperature creep resistance of the finished fastener and avoids permanent deformation under long-term heavy load. Three mature surface treatment solutions are available for customers to select: black oxide for normal high-temperature dry environment, hot dip galvanizing for outdoor damp and corrosive sites, and stainless steel polishing for chemical marine anti-corrosion working conditions. Each surface treatment strictly follows international anti-rust processing standards to extend the service cycle of the fastener in complex environments.

Core Production Technology & Mechanical Performance

Complete manufacturing flow of High Temperature Heavy Duty Hex Structural Bolts covers raw material cutting, cold heading forming, full thread precision rolling, high temperature tempering and finished surface finishing. The tempering process adopts constant temperature furnace heat preservation at 690℃ to 730℃ for more than 120 minutes, which eliminates internal machining stress thoroughly. After standard mechanical testing, the minimum tensile strength of the finished product reaches 830MPa, the yield strength is not lower than 725MPa, and the sustainable working temperature can reach up to 538℃ without performance attenuation. All thread teeth adopt precision rolling craft, the tooth surface roughness is controlled below Ra3.2, which can realize close fit with matched heavy hex nuts and prevent loosening under alternating load. Ningbo Gangtong Zheli Fastener Co., Ltd is equipped with 16 sets of numerical control automatic thread rolling equipment, which can guarantee consistent dimensional tolerance for every batch of finished fasteners and reduce manual processing errors to the minimum range.

Wide Application Range & Stable Inventory Supply

Industrial engineering purchasers from petrochemical, metallurgy, power and steel construction industries widely deploy High Temperature Heavy Duty Hex Structural Bolts as core connection components. Typical usage scenarios include high-pressure fluid conveying pipeline flanges, high-temperature smelting furnace fixing frames, large-span steel workshop main beam connection and power station thermal equipment assembly. Our warehouse maintains complete standard inventory covering specifications M10 to M64, with daily average inventory turnover volume stably exceeding 12 tons, which can rapidly respond to small trial orders and large-scale engineering bulk orders at the same time. Before packaging and delivery, all fastener batches need to pass hardness test, tensile destructive test and thread matching inspection to screen out defective products completely. Ningbo Gangtong Zheli Fastener Co., Ltd has established long-term cooperative relations with multiple regular alloy steel smelters, forming a stable raw material supply chain to avoid raw material shortage delaying customer production plans.

Strict Full-Batch Quality Inspection & Customization Support

Independent professional physical and chemical inspection lab is built to carry out three rounds of performance detection for every batch of fasteners. The complete detection list includes surface hardness test, room-temperature tensile test, high-temperature endurance test and thread size measurement. All original test records, sample photos and parameter data will be filed and stored for more than 2 years to meet customers’ product traceability and third-party audit demands. Apart from standard sizes, the technical team accepts customized demands of special length, non-standard thread pitch and composite surface treatment. Professional matching suggestions will be provided according to customers’ actual operating temperature, load weight and environmental corrosion degree to help buyers select the most cost-effective fastening scheme for their projects.