The 10.9S torsional shear-type high-strength structural steel bolt is a specialised fastener designed specifically for the efficient and precise connection of steel structures. The key difference compared to large hexagon head bolts lies in the use of a ‘torsional shear control’ mechanism, which achieves precise pre-tensioning by shearing off the star-shaped head at the bolt’s end, thereby completely resolving the issues of uneven pre-tensioning force and low construction efficiency and difficulty in quality control, making them the preferred fasteners for large-scale steel structures and high-end engineering projects.

Precise pre-tensioning, controllable quality, and elimination of human error

The core advantage lies in the ‘torque-shear integrated’ design; by using a specialised torque-shear wrench to shear off the hexagonal head at the end, standardised pre-tensioning is achieved, with a preload deviation of ≤±5%. This completely resolves the issues associated with large hex head bolts, which rely on manual torque control and are prone to over-tightening or under-tightening. Construction quality is more consistent, and there is no need for calibration by specialist technicians, thereby lowering the threshold for manual operation. It is particularly suitable for large-scale, high-standard steel structure construction scenarios, preventing connection loosening and structural safety hazards caused by uneven preload.

Efficient installation, saving time and labour whilst reducing labour costs

The specialised torque-shear wrench is easy to operate, completing both tightening and shearing in a single step. Installation time for a single bolt is reduced by over 40% compared to standard hex head bolts, and there is no need for repeated torque checks, significantly improving installation efficiency. Furthermore, the sheared flower-head design serves as a ‘pre-tensioning compliance indicator’, facilitating on-site quality inspections and reducing the workload associated with quality control. This makes them ideal for projects with tight deadlines, such as large industrial plants, bridges and high-rise buildings, helping clients to shorten construction schedules and reduce labour costs.

Safe and reliable, with excellent resistance to loosening, suitable for high-end engineering projects

Manufactured using the same materials and processes as 10.9S large hexagon head bolts, these fasteners offer high strength and toughness, as well as resistance to fatigue and impact. Upon shearing, the shank and nut remain tightly bonded, providing outstanding resistance to loosening. They can withstand extreme conditions such as high-frequency vibrations from heavy machinery and strong wind loads on bridges, with no risk of loosening or detachment. Furthermore, the fracture surface is smooth with no signs of brittle fracture, meeting the safety requirements of high-end steel structure projects. These bolts are widely used in landmark buildings and major engineering projects.

Compliant with national standards, traceable quality, and hassle-free acceptance

We strictly adhere to the latest national standard GB/T 1231-2024 throughout the entire process. Having passed specialised tests including torque coefficient, slip resistance coefficient and torsional shear moment, we can provide a full set of documentation, including authoritative third-party test reports, product certificates of conformity and material certificates. Quality is fully traceable throughout the process, fully meeting the acceptance standards for all types of high-end engineering projects and eliminating the need for rework due to non-compliant products.