One of the major misconceptions about using 316 stainless steel hex tap bolts and 18-8 Stainless Steel hex lag bolts is the fact that most people think that they are not magnetic. This is because generally speaking, not all types of steel are considered magnetic. This can create a number of problems when you are thinking of using fasteners. In some settings, the effect of magnetism on the fasteners is an important consideration when choosing them.
For instance, if you are designing or repairing an MRI machine, you can’t afford to use fasteners that are even slightly magnetic. The fact that the machine generates such as huge amount of force means that even if a fastener has only slight magnetism, it might be ripped off its anchoring and end up injuring the patient. This might be the basis for a lawsuit against the company that manufactured or repaired the machine.
Some types of steel are magnetic
The first thing you need to realize is that there are some types of stainless steel that are magnetic. In the manufacturing industry, stainless steel is normally divided into five classes. The austentic type of stainless steel is the most common. Only one of the other five types of steel are not magnetic, and the rest are depending on the nature of their microscopic structures. The only issue is that the degree of the magnetism might vary depending on the structure of the metal.
How the steel can be made magnetic
It’s also important to note that there are some processes that can convert a nonmagnetic piece of stainless steel into a magnetic one. One of the most important of these is when the structure of the steel is changed in such a manner that it then includes a metal that has some degree of magnetism. In the manufacturing field, this is a process known as martenisitc transformation. This is normally achieved in one of two ways: through cold working and slow cooling.
How to reduce magnetism in stainless steel
If you want your fasteners to have as little magnetism as possible, there are some processes that you should insist on getting done. One of these is to reduce the process of cold working during the manufacturing process. This would require that you consult the company manufacturing the fasteners directly, and asking them to do this for you. You could also find a distributor who has fasteners that conform to this specification.
In addition to that, you may also need to have the fasteners completely annealed following the cold working process. This is one of the most effective ways of completely eliminating the magnetism in the end product. However, there are a few scenarios where it might not be feasible.
In summary, not all stainless steel fasteners are nonmagnetic. However, there are things you can do to ensure that the magnetism in them is reduced to the bare minimum. Understanding the mechanics behind this will make it much easier for you to decide on how to buy the fasteners.
Started my career in the fastener world in 1969 at, Parker Kalon Corp. a NJ based screw manufacturer located in Clifton, NJ working in inventory control, scheduling secondary production and concluding there in purchasing. In 1971 I accepted a sales position at Star Stainless Screw Co., Totowa, NJ working in inside sales and later as an outside salesman, having a successful career at Star I had the desire with a friend to start our own fastener distribution company in 1980 named: Divspec, Kenilworth, NJ. This was a successful adventure but ended in 1985 with me starting Melfast in August 1985 and have stayed competitive and successful to date. Melfast serves the OEM market with approximately 400 accounts nationally.