The M8 bolt size is one of the most common metric bolt sizes. This type of bolt is commonly used for applications requiring moderate strength. It is made of low carbon steel and zinc plated for corrosion resistance.
Metric fastener sizes are specified using diameter and thread pitch dimensions. If the pitch definition is omitted then it is assumed to be coarse threaded.
Length
The length of an M8 bolt is about 13 millimeters, but this measurement does not include the height of the bolt head. The hex nuts that are commonly used with this bolt size are slightly taller than standard hex nuts, so if you’re measuring for a specific nut size, be sure to take this into account.
Metric bolt sizes are based on diameter and thread pitch, while American bolts are typically measured in inches. The thread pitch can affect how much torque is required to tighten the fastener.
Metric bolts have a specified length, which is determined by subtracting the thread pitch from the overall bolt diameter. You can use this information to calculate the correct hole size for tapping the bolt. For example, a bolt with a standard coarse thread pitch requires a hole that is 6.75 mm in diameter. The length of the bolt also impacts its tensile strength, which is the amount of stress or stretch the fastener can handle before breaking.
Diameter
When it comes to choosing the correct bolts for your project, size and specification are vital. However, the vast array of threaded fasteners available can make this task difficult. Bayou City Bolt aims to make things easier by helping you understand the different specifications that govern your bolts and nuts.
Metric bolts and screws are often specified by their diameter, pitch, and length in millimeters. The last number in the metric designation indicates the thread pitch, or the distance between adjacent threads, which is also measured in millimeters.
A metric bolt’s diameter is determined by subtracting the thread pitch from its nominal diameter. The result will indicate the minimum hole size required to tap the bolt. For example, a metric M8 bolt with a coarse thread pitch will require a hole of at least 6.75mm. A fine-thread M8 bolt will require a smaller hole of around 5.75mm. This calculation is important, as the wrong hole size could damage your bolt or cause it to jam in the application.
Thread Pitch
M8 bolts have a thread pitch of 1.25 thread per millimeter. The threads on these bolts are spaced closely together, which makes them strong and durable. This tight fit also helps prevent loosening over time. This tightness also provides a better seal in harsh environments.
Metric fasteners come in both coarse and fine thread options. However, when the thread pitch is omitted from a specification, it is assumed that the bolt is coarse threaded.
To determine the requisite tapping drill size, you simply need to subtract the bolt’s diameter from the thread pitch. The result is the suggested drill size for a clearance hole. You can use the chart below to determine which drill size you need for different sizes and grades of bolts. This is especially helpful when deciding whether to purchase coarse or fine threaded fasteners. This way, you can be sure that the bolts will fit properly. This will help you avoid expensive mistakes and ensure that your project is successful.
Material
When it comes to choosing the right bolt for your project, you need to consider the material it is made of. This can help determine the strength of the bolt and how much pressure it can handle. Metric bolts are usually marked with a class number that indicates the type of material. The higher the class, the stronger the bolt.
Zinc-plated steel is one of the most commonly used materials for bolts. It has good corrosion resistance and is inexpensive to manufacture. Hot-dipped galvanized steel is another common bolt material. It has better corrosion resistance than standard zinc-plated bolts and is durable in outdoor environments.
If you are working on a bicycle, you will probably encounter M8 bolts in brake and shifter lever mounting bolts, quill stem bolts, and anchor bolts for seat post clamps. You may also see them on derailleur hanger bolts and in other applications. They have a coarse thread pitch that requires a specific tapping drill size.