This structure is a laboratory-scale, hand-driven bench-top tensile testing machine, 20 kN capacity.

Learning Outcomes

• Tensile tests up to 20 kN on specimens made of different metals, to find material characteristics such as upper and lower yield strengths, tensile strength and overall extension
• Tests of Young’s modulus (E) for the specimen material

A sturdy base holds a hand-driven worm and wheel gearbox, driving a lead screw with approximately 400 mm of travel. The mechanism uses ball races and self-aligning ball thrust races in the direction of loading. These low-friction bearings with the large handwheel allow the user to apply maximum load with minimum effort. The load-measuring mechanism is a strain-gauged load cell that connects to a microprocessor-controlled digital display. The load display unit has a ‘peak hold’ function to register the maximum load before the specimen breaks. A sliding digital display measures the tensile displacement (extension) over the entire movement. The tensile specimens mount between the load application mechanism and load cell, in collet chucks via ball-jointed spigots. This ensures purely axial loading.