How to Choose Button Socket Cap Screws

Button socket cap screws by Monroe Engineering

Not all screws have a Phillips or flat head. Some of them have a circular-shaped head with a hexagonal drive type. Known as button socket cap screws, they can be driven into and out of objects using a hex key. You can insert a hex key into the head, after which you can turn it to tighten or loosen the button socket cap screw. When choosing button socket cap screws, however, there are several things you should consider.


You can find button socket cap screws available in different materials. Stainless steel is a common material in which they are made. Consisting of iron and chromium, it offers a high level of protection against corrosion. With stainless steel button socket cap screws, you won’t have to worry about corrosion-related degradation. You can use them in humid and moist environments, and due to their chromium content, they shouldn’t corrode.

Standard vs Pellet

There are standard button socket cap screws, and there are pellet button socket cap screws. Pellet is a specific style of fastener that’s designed to be inserted into a pre-drilled hole. Pellet socket cap screws still have a similar head as their standard counterparts. They are shorter, however, and offer self-locking capabilities.


Whether standard or pellet, you should consider the length when choosing button socket cap screws. The length, of course, can vary. Some button socket cap screws are just 0.25 inches long, whereas others are over 1 inch long.

Thread Type

Something else to consider when choosing button socket cap screws is the thread type. Like with most fasteners, you can find button socket cap screws with different types of thread. Some of them have coarse thread, whereas others have fine thread. Coarse thread is typically preferred because it creates a stronger and more secure hold than fine thread. Button socket cap screws with fine thread may loosen, or they may even come out of the objects with which they are used. Therefore, you may want to choose button socket cap screws with coarse thread to prevent them from loosening.

Tamper Resistant

Some button socket cap screws are designed with a tamper-resistant head. Temper-resistant button socket cap screws are distinguished from other types of button socket cap screws by their head. While most button socket cap screws have a circular-shaped head with a hexagonal drive type, tamper-resistant button socket cap screws feature a different type of head. They are designed to support an unconventional drive type, thus protecting them from tampering.