What Is M8 Bolt Size?
M8 bolt size is a common thread used on a variety of components on a bike. It’s found on derailleur mounts, seat post bolts, crank bolts and other parts. It’s important to understand what each part represents so you can choose the right bolt for your needs. Bolts are generally made of two materials; either low carbon steel or high strength aluminum. Often they have zinc coating to provide moderate corrosion resistance.
The number indicates the nominal diameter of the bolt shank or shaft, and the letter identifies it as metric. For example, the M5 bolt has a diameter of 5 millimeters. The last number relates to the distance between the threads on a screw, or pitch. The M8 bolt has a thread pitch of 1.25 millimeters.
While the diameter and pitch are the most important dimensions for a screw or bolt, the length is also an important consideration. Metric fasteners are commonly referenced using their diameter, pitch and length in millimeters. The length dimension is abbreviated as L and may be indicated as dL or DL depending on the manufacturer.
Metric bolts are typically sorted by their pitch and diameter, while American fasteners are sorted by their thread length. This difference makes it difficult to convert an imperial bolt to a metric one, but it’s not impossible. It is also important to note that a metric bolt’s thread depth can vary as well. It can be full, thin, nyloc or dome, and it can have a variety of other specifications as well.
When a bolt is gradually loaded it will reach a point where it begins to stretch and then break. This is called the proof load and it’s a good idea to test the strength of your hardware to ensure it can safely hold the desired weight.
The most common bolts are made from low carbon, cold-rolled steel and are coated with Zinc to protect them from corrosion. They are available in various grades with the highest grade providing excellent strength and corrosion resistance. Some bolts are also made from Alloy steel, which contains additional elements such as nickel, manganese, chromium and others to provide increased strength, hardness and wear resistance. These bolts are usually black in color because they’re coated with additional black oxide. These bolts are typically only used for outdoor applications and are more expensive than their lower-grade counterparts. A higher-grade bolt is capable of holding up to three times as much weight before reaching its proof load. The table below shows the different types of bolts and their respective sizes. It also includes the corresponding hole sizes that should be drilled for each type. The holes sizes are calculated by deducting the metric bolt’s standard coarse thread pitch from its diameter and then multiplying that value by the required tapping drill size. A more detailed chart is also provided for determining the necessary clearance hole sizes for each type of bolt. M8 bolt size