Reprint from LINK, Summer 2020
A number of years ago I owned an old John Deere tractor that was clearly showing its age. As I tooled around my yard cutting the grass I noticed that the engine was laboring more and more and it was consistently blowing oily blue smoke from the exhaust. I knew it was time to either retire the tractor or rebuild the engine. Although I had never done it before, I decided I would try my hand at rebuilding the engine.
Reprint from Hardware & Fastener Components Magazine, Vol. 51
What are Tension Control Bolts?
Tension Control Bolts have a domed head, body, threads, and a splined tip known as the Pin Tail. (See Figure 1) Tension Control Bolts are part of the structural bolting family given by ASTM F3125. Like the other structural bolt variations, these come in two different types, regular and weathering steel and two different strength grades, 125,000 psi and 150,000 psi. The 125,000 psi version is considered Grade A325 and marked as A325TC or A325TC depending on whether it is Type 1 (regular steel) or Type 3 (weathering steel), respectively. The 150,000 psi version is considered Grade A490 and marked as A490TC or A490TC depending on whether it is Type 1 or Type 3, respectively.
Reprint from China Fastener World Magazine, Vol. 48
Most people probably never give the fasteners that hold together most of our modern contrivances a second thought. They simply take for granted that these components will do what they were designed to do. In fact, I believe that few people really appreciate that fasteners are perhaps the lowest cost, most highly engineered components in the products that they are used in. Many times they are truly critical and our lives depend on them working flawlessly.
Although it is likely that this notion can be applied to any application, it is especially true of structural bolting technology. These are the fasteners we depend on every day to hold up bridges, buildings, and other important structures. There is a great deal of information available for the production, installation, and proper use in the consensus standards pertaining to these fastener assemblies. This article will attempt to explore the fundamental principles related to this very important category of fasteners.