EM 309.01 | Screw Efficiency Apparatus

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.

Experimental Capabilities

• 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.

Scope of Delivery

• 1 experimental unit.
• 1 set of bolts in transparent container.
• 1 set of instructional material.