Every auto shop employee needs to know what fasteners auto manufacturers use the most. Here are the different fasteners that manufacturers in the automotive industry use most often.
Imperial Fasteners
Auto body shops use two types of pins: imperial and metric. They feature different grades, materials, and proof loads.
Imperial pins keep the vehicle frame attached to the vehicle’s inner workings. The number of teeth on the thread pitch determines the measurement. The typical grades for imperial fasteners are 2, 5, and 8. The quality depends on the size and mechanics of the vehicle.
Metric Fasteners
The grades for metric fasteners are slightly different, with the measurements appearing as millimeters. The measurements for metric fasteners typically used in auto body shops are 5.8, 8.8, and 10.9. These measurements depend on an application’s body.
One metric fastener that workers use when maintaining a vehicle’s build is the metric flange bolt, which holds the frame of a vehicle—usually a truck—together.
Material
Both metric and imperial fasteners are made from the same compounds, but each grade varies in composition. For example, grade 8 imperial fasteners are made from medium alloy carbon steel, whereas grade 2 fasteners comprise a low or medium carbon steel.
Proof Load
The proof load is how much expansion the bolt’s elastic has—in other words, it determines the tension limit. Here’s a quick breakdown of the proof load for each bolt type:
- The proof load for an imperial grade 2 fastener is at least 385MPa (megapascals).
- A 10.9mm metric fastener will have a proof load of 840MPa.
Applications of Metric and Imperial Fasteners
Imperial and metric fasteners go hand in hand, but each bolt’s grade and millimeter size work best on certain parts. For example, you wouldn’t utilize an imperial grade 5 fastener or a metric 8.8mm fastener on body hardware because neither would fit. These grade and sizes are best for components such as key brackets, the suspension, or steering mechanisms.
Learning about bolt sizes builds a stronger knowledge for you and your fellow workers. With this newfound knowledge of the different fasteners used in the auto industry, you now know what sizes to look for and what applications work best with these ranges.
