What options are available for different configurations of clevis pins?
A tie rod assembly, used to brace steel columns, large timbers or canopies, often comes with clevises which are attached to mounting plates by a pin. These pins typically come in three configurations: headed pins with cotters, straight pins with cotters, and A325 structural bolts with a nut.
Headed or ‘vertical’ pins possess a small head on one end of the shank and a hole with a cotter pin on the other end. The shank runs through both the clevis ends and the mounting plate, after which a cotter pin (or ‘split pin’) is run through the bottom hole securing the connection. Headed pins are made of cold headed, low carbon steel wire. Headed pins 1-1/4” diameter and larger are typically machined from ASTM A108 Grade 1117 bar stock. The larger pins can also be machined from other grades of round bar.
Straight or ‘horizontal’ pins possess a smooth shank with holes on each end. The straight pin runs through both clevis ends and the mounting plate after which cotter pins are run through both holes to secure the connection. Straight pins are typically manufactured from ASTM A108 Grade 1117 bar stock. Pins can also be manufactured form several other grades of round bar.
ASTM F3125 Grade A325 heavy hex structural bolts are sometimes supplied with clevises to serve as the connecting pins. In this case, the bolt would run through both clevis ends and the gusset plate, and the connection would be secured by assembling a nut onto the bolt.
A headed pin is the most common configuration of clevis pin up through 1” in size. Above 1” in size a straight pin is usually provided, although a headed pin is often preferred when the long axis of the pin is vertically oriented, the fact from which its name is derived. This is due to the risk of a cotter pin having a potentially higher rate of failure than a headed end when they are in this configuration. The A325 is sometimes preferred as a high strength alternative to a headed pin, but care needs to be taken that the threads of the A325 do not fall within the shear plane.
Portland Bolt can supply tie rod assemblies featuring clevis pins in any of these configurations. If you have a project that requires clevises, give Portland Bolt a call and one of our experts will assist you in getting the correct product.