Tension control bolts install from one side with an electric shear wrench that snaps the spline at the correct pretension, so inspection is visual and the process is fast. We stock TCB assemblies in Umm Al Quwain from M12 to M52 (S10T / F2280 / EN 14399-10 HRC) with nuts and hardened washers, black or zinc-aluminium coated.
A tension control bolt (TCB, twist-off bolt) has a round (button) head, a heavy hex nut and a splined tail on the thread end. The shear wrench holds the spline and turns the nut; when the bolt reaches the designed tension the spline shears off, leaving a clean end that proves the bolt was correctly tightened. TCBs eliminate torque calibration and turn-of-nut marking and need only one operator.
Applications
- High-rise steel frames and composite floors
- Bridges, viaducts and gantry structures
- Warehouses, PEB and long-span roofs
- Stadium, airport and station structures
- Wind tower and transmission structures
- Industrial plant and pipe rack connections
Standards, grades & finishes
Assemblies to ASTM F3125 Grade F2280 (150 ksi, formerly F2280) or Grade F1852 (120 ksi), JSS II-09 S10T, EN 14399-10 HRC 10.9, with nuts to ASTM A563 DH / EN 14399-10 and washers to F436 / EN 14399-6. Supplied as lubricated, matched assemblies with lot-specific tension test reports (pre-installation verification).
This item is imported from approved mills and held in stock in our Umm Al Quwain warehouse alongside the anchor bolts, studs and plate washers we manufacture ourselves, so complete bolt sets ship from one source. Tensile, hardness and chemical testing is carried out by independent UAE-accredited laboratories, and EN 10204 3.1 certificates are issued with every batch. We supply across the GCC, MENA and Africa.