Structural Tie Rod Systems

Roll Thread

Hamma tensile rods are roll threaded as opposed to cut thread. Rolled thread offers distinctive advantages over cut thread due to it's inherent production process. The granular flow of the major diameter (tip) & minor diameter (root) are re-formed in unbroken continuous lines during a compressed rolling process. This continuous compressed granular line resists stripping because shear failures would need to take place across all lines rather than a single grain. This is particularly evident in the root section of the thread where compress granular lines increases hardness up to 30%.

The active stress areas are also maximised by compressed redistribution of the material, as opposed to material lost. Accuracy on pitch angle, diameter, thread angle, and surface smoothness are also much better achieved by the compression rollings process as opposed to a cut thread which will be dependent on the machine operator. Equally as important is the ability for a machine operator to maintain consistency over long period of machining.

allspars-tie-bar-dimensions.pdf (122.5KB)