A widely accepted way to express the spacing of Hexagon Flange Bolt ( https://www.chinaweigao.com/product/bolt/hexagon-socket-head-bolt.html ) is to indicate whether it is thick or thin. In rare cases, you may also see ultra-fine threads.

Some fasteners do not indicate the pitch size. So what if there are no clear instructions? Fasteners that exclude pitch information are generally classified as coarse.

You must note that fasteners classified as coarse using threads per inch are generally thicker than metric fasteners classified as coarse.

For example, the M14-2.0 screw is considered coarse. The thread pitch is 2.0 mm or 0.079 inches. Within the United States, 9/16-12 screws are considered comparable, and there is also a rough classification. However, its thread spacing is 0.083 inches.

In this example, the pitch of the American screw is thicker than that of the metric screw. In some rare cases, comparable US equivalents are more refined than their metric counterparts, so you need to pay attention to and use the conversion information listed above.

Compare the length with the metric system. Inch fasteners
One common feature of fasteners is how to measure length. The only difference is that the metric system uses millimeters to indicate length, while American fasteners use inches. The following describes how to measure various types of fasteners.

Sleeve, low sleeve, cheese, hexagon, button and disc: measure the length of the fastener as everything under the head.
Flat head: Measure the entire fastener from beginning to end.
Oval head: Measured from the point where the dome and tapered bearing meet to the tip of the fastener.
Metric fastener materials
Once you understand the naming convention for metric fasteners, you will make another decision before buying. Threaded Rods And Eye Bolts ( https://www.chinaweigao.com/product/bolt/threaded-rods-and-eye-bolts.html ) can be made from a variety of materials, including:

steel
stainless steel
aluminum
brass
Hot dip galvanized
Polyamide
Silicon bronze