Compression limiters solve automotive plastic cracking problem

The area around an M5 bolt mounting hole was cracking when the torque load exceeded the specification. Controlling the torque within the required limits was difficult and so it was also not always possible to ensure the quality of the final product as the cracking did not always occur immediately upon installation. Clearly a more robust design was required that would withstand more torque without fear of failure. Most plastics are not able to handle the stresses imparted by the tightening torque of machine cap screws. However, for these types of applications, Spirol Industries has developed a line of compression limiters that can withstand the torque loads and prevent excessive compression of the plastic host material. For such applications, Spirol offers brass series CL 101 compression limiters that can be installed with a Model HP Pneumatic Heat Insert Driver. The heat installation causes the plastic material to melt and flow into the retention features on the limiter which prevents it from falling out and eliminates most internal stresses in the host. .