The Features Every Socket Head Cap Screw Must Have

Socket head cap screws are special. They’re made with a built-in hexagonal internal drive. It's what makes socket screws different from other screw head drive designs.   

They also need a unique kind of wrench—an Allen or a socket wrench. But that’s not the only thing that sets them apart. 

Let's take a closer look at what makes them so unique and reliable.

A Screw Like No Other

They’re squared off at the tip and are popular because they’re versatile and fit many modern construction applications.  

The physical differences between normal screws and socket screws are usually minor.

However, socket screws are special, they give you increased performance combined with features found on standard hex fasteners. The nut and bolt is the most common point of reference.

Such features make them more convenient and easier to use than any standard format screw set. The middle ground is valuable, especially when working in a confined space with no wrench hex fasteners.  Looking for fully threaded options? We can help!

What Do You Call A Socket Head Cap Screw?

Socket head cap screws are very popular. They also have several different names. 

Some of them include:

• Cap head socket screw
• Hex socket head screw
• Basic socket cap screw

It has a hexagonal socket, a cylindrical barrel-shaped head, and its head diameter is roughly 1.5 times larger than the nominal thread diameter.

It's widely applicable in assembly lines and industrial production, including furniture manufacturing, the automotive sector, steel fabrication, and machine tooling application. The screws are easy to install, tighten, or loosen. They also offer robust clamping strengths that last for years and retain an impressive and tidy finish.

Top Features of Socket Head Cap Screw

You can pick out a cap head by looking at its hex drive hole: It’s typically threaded across the whole shank. They were originally created for tight fits, or projects that didn’t leave enough room for a typical nut and bolt or a socket wrench.

Socket head cap screws are great because they make it easy to tighten or loosen them. You don't need external clearance, as you do with hex head screws, to use a socket or spanner. This is what makes a cap head screw ideal for tight areas.

What They’re Used For

Most people use the cap head screws with the head recessed within a counterbored hole. To provide a clean look and to protect protrusions that are vulnerable to harm, it leaves the end of the head flushed and the surface fixed. It's a perfect choice for assembling sporting equipment like bicycles.

What Grades Do They Come In?

They’re graded according to their strength. And when grading them, two numbers separated by a decimal point, are used. 

As bolt expert Dr. Jody Muelaner explains, the first number represents the yield strength ratio to the ultimate tensile strength (UTS) in MPa, while the second is the ultimate tensile strength (UTS) in MPa.

Socket head cap screws are available in grades 12.9. Generally, they have a UTS of 1200 MPa and yield 90%.

Big Bolt Fastener Supply Company

At Big Bolt, we supply and manufacture all fastener types in the United States. From stainless steel to fully threaded, to metric sockets and button heads, we can do it all.

Our stringent forging, tensile testing, and quality control strategies ensure we’re putting out high-quality fasteners that will stand up to the most rigorous conditions. 

Whether you’re in the market for a special socket head cap screws, or something else that needs quality fasteners manufactured to specifications, contact us today. We’re happy to help with your next project.