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. 186
In construction applications where predrilled and tapped joint members are impractical, Drill Screws are an exceptionally versatile and helpful fastener product. Drill Screws can be easily assembled into and through a wide assortment of building materials without the need for any access to the back side of the joint. The application opportunities are abundant both for interior and exterior purposes. Drill screws are excellent resources on the interior, where they are commonly utilized to attach gypsum board, wood members, and other metal components to metal structural members and studs. Generally, the interior environment is controlled and these screws are not subject to challenging or abusive environmental conditions. Drill Screws are also highly favored by installers of metal roofs and cladding. Drill Screws provide an easy way to pierce the metal roof or cladding sheets and the underlying steel structural components without the need for any predrilling of pilot or clearance holes. Unlike interior environments, however, the exterior of the building will be subject to whatever variable environmental conditions the climate zone is known for.
Reprint from China Fastener World Magazine, Vol. 190
Heat treating fasteners is a complicated topic with many details to keep track of. The following are some questions and answers that should shed some light on basic concepts.
Reprint from China Fastener World Magazine, Vol. 53
Very early in my career I worked on a very interesting project. In the U.S. after a new car is assembled, it is either loaded into a truck or onto a train for delivery. In this case, our customer’s new model vehicle was loaded onto a train car for shipment across the country. When it arrived on the other end of its journey the cars would not start and could not be offloaded. It did not take long to discover that the glove box doors were opening in route, causing the glove box light to come on, and the battery to drain down. When the root cause of this problem was investigated it was quickly determined that the plastic ABS bosses which accepted the screws that held the glove box door assembly together were completely cracked and broken. The Type AB screws that had been used exerted so much radial stress on the plastic ABS bosses that they had destroyed them causing the plastic to fall away, the doors to flop open, and the new cars to arrive in an inoperable state.
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.
Reprint from Fastener World Magazine, Vol. 166
In April of 1912, the “unsinkable” luxury liner Titanic would set out on her maiden voyage, only to collide within several days with an iceberg and sink in the freezing waters of the north Atlantic. The sinking of the Titanic would become, perhaps, the most iconic of all modern maritime accidents, and one that has been memorialized with multiple documentaries and blockbuster films such as James Cameron’s 1997 adaptation of the disaster.
For many years it was believed that the iceberg tore a long gash in the Titanic’s hull. Exploration and analysis of the ship and its parts, however, seem to suggest a different story. The one that emerges is of substandard iron rivets, already functioning at their margins, overstressed during the collision, breaking, and allowing hull plates to separate and seawater to flood inside.
Certainly there were many factors in-play, but, yes it seems likely that the rivets failed, dooming the “unsinkable” Titanic to catastrophic failure and so many of its passenger and crew to a watery grave.
As this story illustrates, rivets can and do play an exceptionally important role in the life and function of the products and structures in which they are used. Although other technologies have replaced many of the early uses of rivets, such as holding together ships and other large iron and steel structures, rivets are still an integral part of the manufacturing and assembly landscape and are, in fact, imperative in certain manufacturing industries such as aerospace and automotive.
This article will explore the different styles of rivets and some of the equipment used to install them.
Reprint from Fastener World Magazine, Vol. 165
Perhaps one of the most difficult things to join together are thin metal sheets. The thickness is the problem because it just doesn’t allow successful joining using many traditional techniques. Industries such as automotive and aerospace which heavily rely on thin metal sheets for structure and support have traditionally been the first to adopt new joining methods that work. For example, automotive has perfected spot welding and aerospace the use of solid rivets and other special fasteners. As time has gone by, however, new, lightweight materials have been added to the mix, and traditional joining methods are quickly becoming unfeasible or obsolete.
Automotive OEMs are rapidly evolving their body-in-white designs to include a hybrid make-up of lightweight aluminum castings, sheets, or extrusions, mild steel, and high and ultra-high strength steel components. These hybrid structures magnify an already challenging joining scenario into one of much greater magnitude. In particular, the joining of dissimilar materials like aluminum and steel make most traditional fastening methods, like spot welding, unfeasible.
Reprint from Hardware & Fastener Components Magazine, Vol. 41
Histories is full of examples of technologies whose invention long predates their actual practical introduction into society. We could say of these ideas that they were simply “before their time”. Although that would be accurate, it would probably be a fairer assessment to say that they required further maturing and the development of enabling technologies to make them work. Take, for example, one of the most iconic inventions of all-time, the electric light bulb. The earliest light bulbs were invented in the early 1800s. It would be eighty years later that Edison would discover the carbon fiber filament and create the first practical incandescent light bulbs. However, electric light wouldn’t become truly a mainstay in society for another thirty or forty years as enabling technology, such as electrical power generation, transmission and distribution, matured and became a practical reality.
Reprint from Hardware & Fastener Components Magazine, Vol. 44
Several days before Christmas of 2016, a truck driver was passing through Chicago on one of the primary expressways. All of a sudden he noticed a large obstruction in his path and swerved his truck to miss it. Unfortunately, in this maneuver he clipped an adjacent vehicle sending him out of control, flipping his truck on its side, breaking through the center concrete divider, and hitting an on- coming vehicle. Sadly, the truck driver lost his life in this tragic accident.
Accident scene investigators would later determine that this accident was triggered by a wheel that had separated off of another truck and was lying in wait on the roadway for an unfortunate victim. In answer to a spate of such incidents, in 1992 the United States National Transportation Safety Board (NTSB) sponsored a study to examine the cause and frequency of wheel separations from large Class 8 trucks. Shockingly the study determined that there are between 750 and 1050 such reported separations on U.S. roadways every year. That amounts to two to three every day. The study went on to find that the leading cause of such separations was improper nut and stud tightening during the installation or reinstallation after maintenance of large truck wheels.