TM 320 Screw connections testing
The main element of the unit is a slotted, elastically deformable steel block. By tightening the bolt joint, the slotted area is deformed, thereby generating an axial tension force in the bolt. The resulting deformation is recorded by a mechanical dial gauge, and is directly related to the bolt tension force generated.
The bolt joint is tightened and slackened using a special torque wrench, which can be set sensitively with the aid of a threaded spindle. By using an axial bearing, the head friction of the bolt can be largely excluded, so that only the friction of the threaded joint is measured.
- correlation between tightening torque and tension force on standardised bolts
- breakaway torque of a bolt joint
Tension force
- max. 40kN
Force/travel constant
- 20kN/mm (on slotted block)
Max. tightening torque
- 40Nm
Torque/travel constant
- 10Nm/mm (on torque measuring device)
Dial gauge
- 0…10mm
- graduation: 0,01mm
- experiment on the correlation between the tension force and tightening torque of bolts
- bolt size M8x100, wrench jaw size 13mm
- elastic deformation of a slotted block by the bolt
- determining the tightening and breakaway torque with a mechanical torque measuring device
- 2 dial gauges
- sensitive torque setting by hand wheel
- axial tension force in a bolt joint dependent on the tightening torque or the elastic deformation of a slotted block
- measurement of the breakaway torque, including for different fitting situations of the bolt joint
- measurement of thread friction and overall friction