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.
Author Archives: admin
Protecting Fasteners from Corroding Part 1: Basics of Corrosion and Protection Mechanisms
Reprint from China Fastener World Magazine, Vol. 190
The man walked to his tool box, selected the right sized socket and returned to the piece of machinery he was trying to repair. He stared for a moment at the nut he was trying to loosen. It was badly corroded but he had done this many times before. Carefully seating the socket fully on the nut he began to apply pressure. At first nothing happened but then he felt a tiny change in the resistance, reinvigorating his incentive to keep pushing on the bar. Just as he thought he had given it his all, a resounding loud snap occurred catapulting him and his tools forward as his efforts were no longer restrained by the once stubborn but now broken bolt and nut. Crashing into the floor, he yelped in pain and cussed his misfortune.
Using Screws to Fasten into Plastic
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.
A Brief Summary of Accredation, Certification, and Approval Requirements for Aerospace Fasteners
Reprint from China Fastener World Magazine, Vol. 52
Aerospace fasteners are uniquely different from industrial and automotive fasteners in a variety of way. One of the most striking differences between aerospace fasteners and other fastener market segments is the level of reliance on industry certifications, registrations, or regulatory oversight. In fact, in many segments of the market, customers only transact business with approved suppliers that have the right certifications, accreditations, or approvals.
Hydrogen Embrittlement
Reprint from China Fastener World Magazine, Vol. 51
If you are in the fastener industry long enough you will eventually experience first-hand or hear stories about a hydrogen embrittlement failure. In fact, the fear of this potential failure is so palpable that many of the stories have taken on urban legend status. Although many of these stories may not be as exceptional as they are made out to be, there is no denying the fact that a hydrogen embrittlement failure can be painful to all the parties involved.
One might ask why a hydrogen embrittlement failure is any worse than other fastener failure. This is a good question. Perhaps one would argue that it is no worse than any other, we all understand that a failure is a failure. However, others might argue that it is worse because it comes with no warning and its fallout is completely unpredictable. In one case, it might affect almost an entire lot of parts but in another only a small percentage. Additionally, although parts can have all the ingredients for a problem, it only strikes after the parts are put into service. This makes such failures especially difficult because containment and restoration is often extremely costly.
How Environmentally Friendly are Your Fastener’s Finishes?
Reprint from China Fastener World Magazine, Vol. 49
At 9:45 a.m. on February 20, 1947 The O’Connor Electro- Plating Corporation of Los Angeles, California experienced a tremendous explosion leveling the company’s facilities and much of the surrounding four block area. The aftermath of this disaster left 17 dead, 150 injured, and 116 buildings damaged or destroyed. The cause was an unstable mixture of perchloric acid and acetic anhydride, a substance nearly as explosive as nitroglycerin, used by O’Conner in an experimental aluminum polishing process.
Although this example is perhaps one-of-a-kind and certainly not characteristic of the normal consequences of a metal finishing process gone awry, it does illustrate the crucial nature of the processes employed and the serious consequences to human safety and the environment when things go wrong. Additionally, in recent years, stories of gross industrial negligence such as the poisoning of municipal water supplies or polluting the land an industrial facility is located on or near have become all too commonplace. In fact, some of these incidents have been raised to global awareness through television documentaries and films such as “Erin Brockovich” (the story of a California town’s water supply tainted with hexavalent chromium).
The Fundamentals of Structural Bolting
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.
10 Things to Know About Automotive Fasteners
Reprint from China Fastener World Magazine, Vol. 45
During my first twenty five years in the fastener industry I worked for a fastener manufacturer that focused primarily on automotive fasteners. Several years into my tenure I had the opportunity to work on a project outside of the automotive industry, with a large computer and peripherals manufacturer. After many months of project work it was obvious that the project was dead-on-arrival. This was an uncustomary loss and as I reflected on the reasons for this, the one that stood out above all the others was that we were simply not equipped to support the needs unique to this industry segment. We were very capable of providing the necessary application engineering and had the manufacturing capabilities, but we were too ingrained in our own paradigms and lacked important industry specific knowledge so that we failed to execute properly to meet the customer ́s needs.
Fastener Corrosion in Treated Lumber
Reprint from China Fastener World Magazine, Vol. 44
Fasteners, whether they are nails, screws, anchors, or metal connectors play a critical and important role in wood/timber construction. In essence, these products are critical in joining materials together and either carrying
or helping distribute structural loads. In many instances these fasteners are installed in corrosive environments or brought into contact with corrosive materials. Common examples of these conditions include exposure to constant moist or humid conditions, coastal conditions or salt infused air, preservative-treated lumber, and contact with dissimilar metals. Any one or a combination of several of these factors can conspire to corrode a poorly specified fastener resulting in loss of the load carrying capacity of the joint, either by degradation of the fastener, the surrounding wood, or both. Therefore, the specifier of the fastener must be knowledgeable about the service conditions and make prudent selections of the fastener coating or raw material to minimize these risks.
Rivets and How They are Installed
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.