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Metric Fasteners Guidelines

About Metric Fasteners

Metric fasteners are commonly used in the robotics/automation and defense sectors for their prototyping and production runs. Due to the boom in both of these industries, the demand for metric fasteners has increased over recent years. Certain machinery and equipment are designed according to the metric system of measurement, a common standard outside of the United States. As such, these products are only compatible with metric fasteners rather than standard fasteners.

For over 40 years, The Coating House has been a leading supplier of various fasteners, including metric fasteners. As a subscriber to the Industrial fastener institutes IFI connection, we ensure that every metric screw we supply meets stringent industry standards for optimal quality and reliability. To meet a wide range of needs, we offer several types of metric fasteners sourced from reputable manufacturers and custom solutions tailored to your specific requirements.

Types Of Metric Fasteners

The Coating House can supply metric fasteners in a variety of styles, including: 

Socket Head Cap Screws.

Socket head cap screws feature a deep hexagonal recess and thick side walls for high strength. They are particularly well-suited for tight assembly applications where space is limited.

Machine Screws.

Metric machine screws are available in various head styles and materials – common head styles include pan head, flat head, oval head, hex head, and cheese head. They are specifically designed for use with a tapped hole or nut and typically feature a blunt tip for secure clamping.

Shoulder Screws.

Shoulder screws are well-known for their large, unthreaded shoulder. Typically available in stainless or alloy steel grades, metric shoulder screws are used in applications requiring components to rotate or slide.

Captive Screws.

Metric captive screws are designed to remain attached to an assembly even when disengaged. They feature a reduced shank below the head that prevents them from completely detaching. This design allows for efficient and convenient maintenance and prevents the loss of screws during disassembly.

Understanding Metric Fastener Sizes

The key components of metric fastener sizing are diameter, pitch, and length, all measured in millimeters (mm). Sizing for nuts will also be defined by diameter and pitch. To give you a better understanding of metric fastener sizes, let’s take a look at the following example:

M3 x 0.5 x 30

The above metric fastener specification breaks down as follows:

  • M – The letter ‘M’ indicates that the fastener is a metric size.
  • 3 – The number ‘3’ refers to the nominal diameter in millimeters.
  • 0.5 – This refers to the spacing between threads, known as pitch, represented in millimeters.
  • 30 – This is the length of the fastener in millimeters.

In some instances, the size may be described as M3 x 30, without the pitch specified. Because the pitch isn’t listed, the screw is assumed to have a course thread.

Metric Screw Uses & Applications

Because of their metric standardization and versatility, metric fasteners are used across diverse industries for everything from general manufacturing to complex industrial applications. Particularly, metric fasteners are essential for projects involving products or equipment from countries that follow the metric system.

Common industries that utilize metric fasteners include:

  • Aerospace
  • Automotive
  • Construction
  • Defense
  • Marine
  • Plumbing

Let Us Be Your Metric Screw Solution at The Coating House

At The Coating House, we are well-equipped to handle large-scale projects and can provide expert guidance to help you find the right metric fastener for your needs. We supply metric fasteners in a wide range of sizes and styles and can also customize a solution to your unique application. For more information about our metric fastener products, reach out to The Coating House today.