Torque Control Services

Torque control services for structural bolted connections are carried out in accordance with EN 1090 and applicable customer specifications, covering controlled tightening of bolts in different diameters and property classes.
The tightening process for preloaded bolted joints is based on the controlled rotation of the nut relative to a predefined reference mark. The nut and adjacent component are marked prior to tightening, and the required torque or tightening angle is applied using calibrated torque measuring equipment or angle control methods in accordance with EN 1090-1 or project-specific requirements.
For angle-controlled tightening, acceptance criteria are based on angular displacement between reference marks:
Rotation less than 30° is considered acceptable within tolerance limits.
If rotation is between 30° and 45°, at least two additional bolts from the same group must be inspected.
If rotation exceeds 45°, at least two bolts from the same group must be rechecked, and non-conforming bolts shall be replaced where necessary.
All torque control operations are performed using calibrated equipment under approved Inspection and Test Plans (ITPs), ensuring full traceability, compliance, and structural integrity.