Metric Bolt Sizes Guide: Dimensions, Size Conversion Table, Types Of Bolts and Size Chart

If we start to look for where bolt are not used, I can guarantee that we fail to find such a place. People of all walks of life need them for different purposes. But the main importance of the bolts is to strengthen the joints between two different parts of electronic or iron made products. They have great demand within the construction industry as they are used in everything from building a home, to building a bridge. Who knew these tiny metal bits could be so critical to the creation of so many things.

Finding the Right Metric Bolt Dimensions

As bolts are used in different purposes, they need to be sized accurately for the appropriate job.  This means that the metric bolt size should be checked on each bolt before purchase or before use of these construction supplies. When identifying what size of bolt you will need you identify three basic measurements.

The first measurement that determines the size of a bolt is the length, which is determined based on the distance from the tip of the bolt, to the opposite end.  This does not include the length of the head however.  Understanding this metric bolt size is crucial as it will determine if your bolt stick out of the other end of the item that you are working with.

The second measurement that determines the metric bolt dimensions is the diameter of the bolt itself.  Again, this measurement has nothing to do with the head of the bolt, rather the portion that is being turned into another material.

Finally, the third measurement is based on what is often referred to as the pitch.  The pitch is the distance between each individual thread, which is calculated by counting the number of threads on the bolt and dividing that quantity by the distance from the first thread to the last thread. A thread is originally a progressive receding helical ridge shaped along the length of a cylinder. These kinds of ridges are commonly known as the crest because of their position and appearance. The empty spaces between the crests are the root of the fasteners. The ridge and crest of a bolt are shaped like angle which is referred as the helix angle.

When your bolt dimensions are clear, your measurements will be communicated in the following manner:

M 5 x 1.0 x 35

The M denotes that you are measuring in mm of the Metric system.  The first number, the 5, denotes the diameter, the 1.0 is the distance between the threads, and the 35 is the length of the bolt when measured without the head.

Metric Conversion Table

Understanding the way metric bolt sizes are calculated is important when you are working on your own job, and when you are looking at a metric bolt size chart to help you when you are purchasing at the hardware store. Depending on where you live in the world you may have to convert your bolt size from metric bolt size to inches.

Ideally, if you are needing to convert measurements you will be provided with a handy metric bolt or metric nut sizes conversion table.  This table is a comprehensive list of what a bolt would be in the United States, versus in most other nations which rely on the metric system.  This not only allows you to get in and out of the hardware store easier, but it means that if you math skills are not so great you don’t have to worry about messing up on calculating a conversion in your head.

Different Types of Bolts

Keep in mind that when you are working with different projects and different materials you may need to have a different style bolt for each project.  While the measurements are all done the same, including the conversions, it is of particular importance for you to know what type of bolt you are shopping for before you get to the hardware store and have such vast expanses of choices at your fingertips.

The following are just a few different types of bolts that you may need or may have worked with before:

  1. Double ended screw / Dowel screw/ Hanger bolt: Double ended screw type of bolts are just like the wood screw. It has two ends in two sides but don’t have any head. These types of bolts are used for constructing hidden joints between the pieces of wood. On the other hand the hanger bolts are bit different. They have screw threads in one end and machine thread lies in the other end. They are often used to fasten any metal part to the surface of the wood.
  2. Anchor Bolt: Anchor bolts are a different and unique type of bolt. It is actually a package of wet concrete. It takes the help of the screw threads above the surface of the concrete.
  3. Breakaway Bolt: The breakaway bolt has no similarity with the previous two types of bolts. It is a complicated bolt with a shank which is hollow threaded and designed to break the impacts. It has many uses. But it is mainly used to fasten items together.
  4. Plow Bolt: The plow bolt and carriage bolt both have similarity among themselves. The head of a plow bolt is either flat or concave and the underside is cone designed as well which makes them able to fit for countersunk recess. A low bolt is an item which is full of variations, they have variety in their look and obviously in their function and importance.

While the aforementioned bolts are just a few that you might encounter when working in construction, you must remember that the metric bolt sizes of any, and all bolts, is still critical to the success of your entire project.  A proper understanding of how bolts are measured and how you can convert between measurements is especially important.
Next time you seek to construct something on your own, be it for business or pleasure, keep in mind all the many uses of bolts, and the fact that your metric measurements should be done carefully before your project begins.

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