Abrafast has added the Tension Control Fastening System to its inventory of fasteners. The Tension Control Fastening System is a three piece securing system that includes a button head design bolt with a 12-point pintail, a high strength heavy hex nut, and a hardened flat washer.
The button head design involves a larger bearing surface than a hex head designed fastener. In structural applications, the hardened, flat, bearing surface under the bolt head is in contact with a blast cleaned, or primer coated steel beam surface that is commonly coarse due to mill scale. This assures that the surface under the bolt head has a higher friction coefficient than a hardened surface commonly seen on bolts. This is meant to prevent rotation of the fastener when in use.
In addition, the button head of the Tension Control Fastener incorporates a 40 percent larger bearing surface than the common hex head fastener. It assures 40 percent more resistance and clamping force distributed between the bolt head and the structural member to assure less chance of rotation.
The fastener also includes a variety of cost saving features. For example, it offers consistent, reliable tension, and faster assembly time, the bolt, nut and washer is included, and a greater than minimum tension is guaranteed when properly installed.
The fastener is designed to allow for visual inspection of the sheared pintail to verify proper torque-tension coefficient. Consistent tension is not dependent on tools or the skills of the installer.
The fastener is installed using a lightweight electric installation tool that assures less operator fatigue. One operator can perform the installation.
The placement of the Tension Control Fastening System is relatively easy. In fact, it can be done in just three steps.
- Fit the inner socket of the shear wrench over the spline on the bolt and push forward until the outer socket engages completely with the nut.
- Pull the larger trigger on the wrench. The inner socket will hold the bolt in place while the outer socket tightens the nut. The spline will shear off when proper tension is achieved.
- Remove the wrench from the nut and pull the ejection trigger. This will eject the spline from the inner socket of the wrench.
Just like that the installation is done and it can be visually verified.
Make the connection with the washer under the nut in standard and short slotted holes. For long slotted and oversize holes, the washer should be placed under the head of the bolt and under the nut. Make sure that the washer and nut identification markings are facing the opposite direction of the connection so that it can be seen after installation.
Make sure that the fastener’s connection is snug and tight, starting with the most rigid part of the connection.
It is important that the fastener be properly stored. It should be protected from dirt and moisture at the job site. Remove from the container only the number of bolts you intend to use that day. If there are bolts that haven’t been used at the end of the day, return them to the storage container. Never use dirty or rusted bolts.
Seek the advice of one of our employees when selecting the proper Tension Control Fastener for your application. Call us at (630) 882-9010. You will need to select the proper bolt length and be aware of the dimension of the bolt you intend to use. Our staff can also provide you with information on the mechanical properties as well as the fastener tension of each diameter bolt.