NHSSTension Control Bolts are used in a wide variety of highways construction with bridges being the principal structure, but TCBs are also widely utilized in gantries, signage and piling.

Tension Control Bolts Ltd have the National Highways Sector Scheme No 3 (NHSS3) certification for stocking and distribution activities for mechanical fasteners, and our Greenkote® corrosion protection for bolting assemblies is approved for use on highways structures through the Highways Authority Product Approval Services (HAPAS) from the British Board of Agrément.

Highways Bridges

highways1Bridges are subject to high levels of vibration therefore many bolted connections are designed with preloaded bolts in accordance with Specification for Highways Works Series 1800. Most connections are designed as category B (slip resistant at SLS) however category C (slip resistant at ULS) are chosen if oversized or slotted holes are required or where rigidity on a joint is required at ULS. Traditionally such connections have been known in the UK as High Strength Friction Grip (HSFG) connections, however the more modern term in use is preloaded connection.

For short, medium and long-span bridges, HRC TCBs are the preferred preloaded bolting system as bolting installation can be completed far more efficiently than welding or the installation of System HV or HR hexagon bolting assemblies.

TCB bolting assemblies are available in property class 10.9/10 with our Greenkote corrosion protection, but are also readily available in M24 and M30 diameter Weathering Steel which meet the specifications detailed within EN 1090-2:2018 section 5.6.6 for weather resistant assemblies.

Our bridge projects include many examples of flagship highways bridges. If you are at the design stage for a new bridge, or looking at maintenance and strengthening of an existing bridge please get in touch.


Signage and Gantries

TCBs are widely installed in signal gantries. The speed at which TCB assemblies can be installed means less road closure time.

Often only a rolling road block is required to allow the safe and speedy erection which facilitates minimal traffic disruption.

Contact Us

For more information about our products, please contact us.

Greenkote® anti-corrosion protection

Tension Control Bolts Ltd has its own metal coating plant producing an environmentally friendly anti-corrosion coating called Greenkote, which is comparable to galvanising, although it is harder wearing and readily accepts all paint systems. Learn more about Greenkote.