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The Two Processes Involved In Galvanizing Fasteners And Why It Matters To Your Construction Projects

As a construction contractor, you may not have given a second thought to using galvanized fasteners. You know what they are and what you use them for, but did you know there are two processes used to galvanize nuts, bolts, and screws? You may also be interested in knowing that how these fasteners are galvanized is actually very important to their overall effectiveness for securing steel beams at your project sites. You can find all of this information below.  

Hot-Dip Galvanizing

Every last bolt, screw, and nut that is going to be hot-dipped during the galvanizing process is placed in a special tray. Innumerable batches of fasteners and eqally innumerable numbers of dip trays loaded with fasteners are prepped for the dipping process. Some trays are placed inside a vat of molten zinc that is nearly nine hundred degrees fahrenheit. The trays with the fasteners remain in the molten zinc until the natural metallurgical process has caused the zinc to bond to every fastener. Then the trays of fasteners are removed from the molten zinc and left to drip dry. The result is fasteners that have perfectly galvanized screw threads with no leftover zinc particles or shavings stuck to the threads.

Mechanical Galvanizing

During a mechanical galvanizing of fasteners, the zinc is applied by pounding a zinc compound onto the threads of the bolts, screws and nuts with glass beads. (More or less, they are thrown in a tight, controlled tumbler with a lump of compound and glass beads and left to galvanize.) More or less, mechanical galvanization is metal plating, but with thicker, shinier layers of zinc. 

Why These Two Different Galvanization Processes Matter to Your Construction Projects

Hot-dip galvanization creates a fine, thin coating on the fasteners. The bolts and screws fit easily into the matching hot-dipped nuts and do not require any serious power to push the bolts and screws through the nuts. This makes using these fasteners faster and easier.

Mechanical galvanization leaves trace amounts of zinc compound behind, which means that you have to work harder to put the screws or bolts through the nuts because you are essentially "cleaning" the zinc remnants off of the threads as you push these fasteners together. However, mechanical galvanization does tend to create a tighter hold and prettier appearance, a factor that may play into construction projects with bare beams showing. Additionally, you cannot mix hot-dip galvanized screws and bolts with mechanical dip galvanized nuts because the threads on the nuts are much thicker and create a more narrow opening for the bolts and screws. They will not fit together properly and may not hold fast if you force-fit them.