Different Types of Hexagon Socket Head Screws
Hexagon socket head cap screw is a type of screw widely used in industrial sectors and assembly lines. There are many names, but the most common are hex or socket head cap screws. They are widely used because they are some of the strongest screws available (link to tensile strength and torque spec table), are inexpensive, and are very easy to install with a hex wrench. This makes them ideal for many applications where space is an issue. Socket head cap screws are available in various grades of steel, stainless steel and marine grade stainless steel.
Socket Cap Screw Type - Match Metric DIN or ISO Number:
Hexagon socket caps – DIN 912
Lowered socket cover – DIN 7984
Button socket caps – ISO 7380
Flat head hexagon socket caps (counter-sunk) - DIN 7991
Hexagon socket set screws – DIN 916
Socket Cap Screws – Deep hex recesses and thick side walls make them the strongest socket head screw series with the highest preload rating. This is one of the most common Allen screws you'll find.
Low Head Socket Head Cap Screws – 50% lower head height than traditional socket head cap screws. Ideal for situations where traditional hex head caps cannot be used due to height restrictions. Due to the reduced head height, the maximum preload is much lower and therefore cannot be a direct replacement for conventional hexagon socket screws.
Round Head Cap Screws – The round head shape makes them ideal for safe use, as other screws or bolts may snag clothing or other items on moving machinery.
Flat Head Cap Screws – Flat head screws are countersunk with no head exposed above the mating surface. These are often used to assemble close tolerance machinery where head height is critical.
Hexagon Socket Set Screws – Hexagon Socket Set Screws are designed for use where permanent or adjustable positioning of components on a shaft is required.