TurnaSure LLC is the manufacturer of the world’s most comprehensive range of Direct Tension Indicators. TurnaSure’s predecessor was the inventor of the original load-indicating washer, the simplest solution for properly tensioning bolts. Now TurnaSure introduces the revolutionary TurnAnut™ fastener. This ingenious new tensioning device links a TurnaSure® DTI to an ASTM A563 DH nut in the USA. For use in the EU, TurnAnuts will be based on the EN 14399-3 HR nut. The benefits for users are immense. Now the nut, hardened washer and Direct Tension Indicator, previously being three pieces become one piece. This will produce significant cost savings; in transport, handling, possibly single operator tightening, ease and speed of assembly in the field. In addition the possibility of assembly errors is eliminated.

The TurnAnut™ innovation was possible because of the TurnaSure® DTIs unique geometry, covered by worldwide patents. This has enabled the DTI to be fixed directly under the nut as a nut and washer assembly, with superior tightening results. A major improvement compared with the assembly previously having to sandwich a hardened washer between the DTI and the nut. Such a constraint was a shortcoming within the old DTI design. The original straight-sided protrusions could not be fully covered by the nut’s face and were not concentric with the washer face under the nut; hence a hardened washer had to be added in to the assembly.

The use of a combined nut and DTI assembly not only simplifies assembly, but produces a fastener combination with the advantages of a TCB (Twist-off-Bolt). The presence of the DTI ensures that the development of the required tension in the bolt assembly is completely independent of torque.