BLM TPT - Torque Preload Transducer During bolt tightening, the preload achieved depends not just on the torque applied but also from the friction coefficient µ. The friction coefficient may vary depending on coatings, lubricants, geometry errors, finishing etc. All these factors dramatically influence the joint reliability. It is necessary to check µ in a fast and easy way. The ability to test in the production line also provides an immediate response and reduces the risk of overloading lab resources. The BLM TPT torque and preload transducer connected to the two channel BLM 5000 analyzer provides a fast and easy evaluation of total µ. • If µ is too low the preload will be higher than predicted and could generate bolt failure. • If µ is too high the preload could be low causing the bolt to come loose and fail BLM TPT transducers are supplied wit a complete set of adapters to test bolts of different lengths. Bolts can be tested with the original nut or with standard threaded hardened adapters. The test setup is both simple and fast. With only three transducers (TPT 25, TPT 200 and TPT 2000), it is possible to measure screws from size M3 to M24. The two channel BLM 5000 analyzer has special software, supplied as option, for evaluating µ according to the norm EN ISO16047 standard.