Ask and Answer: Tie Rod Assembly Configurations

How are tie rods, turnbuckles, and clevises configured?

Tie rods, clevises, and turnbuckles are an important part of many architectural designs. Canopy supports, structural steel bracing, and walkway hangers are a few of the applications that use these assemblies. The unique configuration allows for field adjustments in both length and tension.
Adjustment
Adjustments are possible by threading opposing ends of the rod right hand (RH) and left hand (LH). Another alternative is to provide two clevises threaded RH and use a turnbuckle in the middle that has RH and LH threads. The assembly length and tension is adjusted by rotating the turnbuckle. Both options allow the assembly to be installed and easily adjusted in place.
Grip
The grip on a clevis refers the distance between the legs. This is the area that will be placed over the plate and held by a pin. Generally, the grip size is calculated by the material thickness plus ¼”. Keep in mind the minimum grip is ¾” for #2 through #5 clevises and 1” for #6 and #7.

Pin
Clevis pins are available headed or smooth and are generally secured with a cotter pin connection. In some applications an ASTM A325 structural bolt can also be used to connect the clevis to the structure. Refer to the Diameter of Pin in Inches chart on the clevis page for the appropriate pin dimensions. This chart is designed so that the pin will surpass the matching rod strength.
Galvanizing
Hot-dip galvanized clevises and turnbuckles are available. It is crucial for correct fit that the clevises and turnbuckles are tapped oversize to account for the additional thickness from zinc on the tie rods. To ensure the proper fit Portland Bolt assembles all parts prior to shipping.
Common Layouts
Tie Rod with Two Clevises and a Turnbuckle

Tie Rod with Two Clevises Only