Torsion of bars (SE110.29)

elastic torsion of a bar under a torque



  • Torsion occurs primarily on axles and drive shafts in motor vehicles and machines.
  • The torsion occurring in the shaft cause cross-sections of the shaft to be pushed together around the longitudinal axis.
  • When a torque is applied to a shaft the cross-section remains flat and no warpage occurs.
  • In the event of minor torsion, the length and radius remain unchanged.
  • The straight lines on the outer circumference of the shaft running parallel to the axis become helixes.
  • Non-circular cross-sections mostly result in warpage.
  • SE 110.29investigates the torsion of a bar under a torque.
  • The bar is clamped into two movable support blocks by a chuck.
  • The torque is generated by a circular disk, a deflection roller and a weight.
  • The clamping length and torque can be varied.
  • The resultant torsion is read-off at two random points on the bar by means of angle indicators.
  • The fundamentals of elastic torsion are illustrated by the round bar.
  • Three other bars are provided in order to investigate special cases: two thin-walled enclosed sections (a tube and a square tube) and a longitudinally slotted tube (thin-walled open section).
  • All the component elements of the experiment are clearly laid-out and housed securely in a storage system.
  • The complete experimental setup is arranged in the frame SE 112.

Technical Details:


  • elastic torsion of bars
  • 2 movable support blocks with clamping chuck for mounting of bars, 1 fixed and 1 movable support
  • 2 movable angle indicators clampable to the bar
  • 4 bars: round bar with full cross-section, tube, longitudinally slotted tube, square tube
  • application of load to the bar by a mass disk, a deflection roller and weights
  • storage system to house the components
  • experimental setup in frame SE 112

Technical Data:

4 brass bars, L=695mm:

  • round bar, Ø=6mm
  • tube, slotted tube Ø=6mm, wall thickness: 1mm, slot width: 0,3mm
  • square tube WxH: 6mm, wall thickness: 1mm

Disk to apply the load:

  • effective radius: 110mm

Angle indicator:

  • measuring range: ±90°
  • graduation: 1°


  • 1x 1N (hanger)
  • 4x 1N
  • 3x 5N

Dimensions & Weight:

  • L x W x H: 1170x480x178mm (storage system)
  • Weight: approx. 27kg (total)

Learning Objectives/Experiments:

  • torsion of a bar
  • shear modulus of elasticity and second polar moment of area
  • angle of twist dependent on clamping length
  • angle of twist dependent on torque
  • influence of rigidity on torsion
  • round bar with full cross-section
  • tube
  • tube, longitudinally slotted
  • square tube
  • calculation of angle of twist
  • comparison of calculated and measured angle of twist

Scope of delivery:

  • 2 support blocks with clamping chuck
  • 2 angle indicators
  • 4 bars
  • 1 deflection roller with fixture
  • 1 cable
  • 1 set of weights
  • 2 hexagon socket wrenches
  • 1 storage system with foam inlay
  • 1 set of instructional material


  • elastic torsion of a bar under a torque
  • round bar, tube, longitudinally slotted tube and square tube as test bars
  • indication of the angle of twist at two random points on the bar


·         Required: SE 112 Mounting frame


Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.