For just about any project, whether it be of the DIY variety or as part of your job, there has probably been a fastener or two involved. That’s because fasteners are versatile, reliable, and pretty cost-effective to use in almost any situation.
Whether you need a hex bolt like the M8 bolt or something else, you need to get them from a quality vendor. All kinds of DIY projects, like building a swing set or putting together a piece of furniture, will benefit from a quality bolt.
Know Your Bolts
Before you can worry about doing any kind of project, get to know how bolts are composed. There are different features to just about any bolt you see. The shaft, threads, and head are the three components of a bolt and each one of them plays a critical role in making that fastener sturdy and strong.
Shaft. The first part of the bolt is the shaft. The shaft is the long, cylindrical part of the bolt. This is also the part of the bolt that takes the brunt of the force and prevents whatever it is joining together from moving. There is the shank, which is the body, that doesn’t have any threads. The shank has smoother contact and more even stress distribution. The shank sits below the surface, so you won’t actually see it.
Threads. The part that actually fastens, generally to a nut, is the threaded area. This is the bottom-most part of the shaft and lets the bolt be pushed in or out of the nut. It mates with the threads in the nut to create a secure, bolted joint. Just about every bolt is going to have at least partially threaded shafts.
Head. The final part of the bolt is the head. This takes on axial forces applied by a driver or wrench. There are different kinds of bolt heads, typically hexagonal. You might even find some countersunk bolt heads that sit below the surface of the material it is being screwed into.
When it comes to bolts, you are going to hear a few different terms. One of them is the thread pitch, which is generally measured in millimeters. This is the distance between two adjacent crests. Reading metric bolt sizing can feel difficult but it really isn’t.
You might find a bolt that has M10-1.0 x 2.0 sizing. The M means metric measurements, the 10 is the diameter in millimeters, the 1.0 is the thread pitch (in mm) and the 2.0 means the bolt length (also in mm). Don’t feel confused by all those numbers when a few quick pointers can make them easily understandable.
Threads per Inch
In addition to knowing the pitch thread, you might need to know just how many threads there are on a bolt per thread inch. You’re generally only going to find this measurement on US and imperial fasteners, but it helps to know just in case. Like reading thread pitch, the seemingly confusing numbers make a lot of sense with just a few quick explanations.
Let’s say you find a bolt that has a sizing of ¼”-20 x 2”. That’s a lot of seemingly random numbers but they each have a purpose. The ¼” means the bolt has a diameter of ¼”. The 20 indicates that there are 20 threads per inch (TPI). Finally, the 2” indicates that the entire length of the bolt is two inches. With a better understanding of bolts and their measurements, you will be able to find the right bolt for the job before you know it.