Socket Cap Screws

Socket head cap screws are a special type of fastener that offer higher tensile strength, better yield strength, and more shear equivalent sizes of hex head cap screws.  Additionally, they require less counter bore because they are internallly wrenched. They are used for critical vehicle applications, machine tools, tools and dies, earth moving and mining machinery, and a wide range of engineering applications. The most important reasons for the increasing use of socket head cap screws in industry are safety, reliability and economy.  Socket head cap screws are ideal for applications in which there is not enough space to maneuver wrenches or sockets. Socket head cap screws from Newport Fasteners come in the following head types:

• Socket Head (Cylindrical) - Socket Head Cap Screws are threaded fasteners with a cylindrical head and a recessed hexagon drive. Socket screws are turned by using a hexagon shaped key and can be tightened to much higher torque specifications than a crossed recessed or slotted drive fastener. Socket screws are often used in applications where there is not sufficient clearance to use a fastener with an external hexagon head. Socket head cap screws are not grade designated as are hex head cap screws. A standard inch series socket head cap screw is 20% stronger than a Grade 8 hex head cap screw and 50% stronger than a Grade 5 hex cap screw.
• Button Head - Socket button head cap screws are mostly used when limited space arises as the heads are not as tall as the cylindrical socket head. The critical characteristic feature of these screws is the wide load bearing surface. This particular quality makes it resistant to looseness. Button socket cap screws offer a wider bearing surface and high tensile strength but are still low profile like other socket cap screws. 
• Flat Countersunk Head - Flat Socket Head Cap Screws are threaded with a head that is tapered on bottom and flat on top. Flat Socket Cap Screws are designed to be used with a countersunk hole that matches the taper of the head and to sit flush on the mating surface. Flat Socket Head Cap Screws are turned by using a hexagon shaped key and can be tightened to much higher torque specifications than a crossed recessed or slotted drive fastener. Flat Socket Head Cap Screws are used where there is not sufficient clearance to use a fastener that would protrude from the surface of the mating item. These socket head cap screws can also be used for appearance purposes.
• Low Head - Low socket cap screws are for use where there is not sufficient space for the protruding head of a normal socket cap screw. Low Head Socket Cap Screws are high strength, precision fasteners with an Internal Hex or Allen drive style head. The Low Head is half the height of standard socket screws and the low profile allows the screws to fit in tight spaces and used in mechanical applications. Because of their reduced head height and smaller socket size, they cannot be preloaded as high as a standard socket head cap screw. Therefore they should not be subjected to dynamic loads. Although low head cap screws are made of the same material as the standard cap screw, socket dimensions prevent it from being preloaded to the same level as the standard cap screw.
• Socket Flange 

We offer socket head cap screws in the following classes of alloy steel, stainless steel:

• Alloy Steel
• 18-8 Stainless Steel
• A2 Stainless Steel
• 316 Stainless Stee
• A4 Stainless Steel
• Metric Class 12.9 Steel
• Metric Class 10.9 Steel
• Metric Class 8.8 Steel

Advantages of socket head cap screws

• As compared to ordinary fasteners, less socket screws of the same size can achieve the same clamping force in a joint.
• As fewer screws are required for a given job, fewer holes are required to be drilled and tapped.
• There is weight reduction as fewer screws are used.
• There will be weight reduction on account of smaller size of the component parts since the cylindrical heads of socket screws need less space than hex heads and require no additional wrench space.

Socket head cap screws look like any other threaded fastener when they're facing away from you. It's only when they're flipped that you realize you're holding something quite different. That screw cap isn't marked by a standard slot or a self-centering cross. No, this fastener type employs an internal hex socket drive (Allen Drive) in place of a familiar drive interfacing ridge. Just why are these hex-shaped socket are heads so popular?

Socket Head Cap Screws: Functions Explained

If someone disassembles a complex piece of machinery, they'll instantly gain an insight into how many parts are required to assemble that machine. There are numerous surfaces to attach, yet little space to make them join because product-compactness means everything. Socket head cap screws are the solution here, for side-applied forces work well in this scenario. A wrench slips in at an angle, the six-sided fastening tool engages solidly with the indented opening, and the necessary fastening force is easily applied.

Manufacturing Applications

The assembly lines of today use tools that have no equivalent outside of that production facility. Basically, accuracy and speed are the biggest possible processing advantages in here. Special tools, either pneumatically operated or electrically operated, rapidly anchor each of a hundred different bolts and screws in place, at which point the assembling part moves on to the next workstation. The socket head cap screw has been widely adopted on the assembly line because of that ability to accept side-applied drive force, plus a capacity to resist wrench slippage. These are essential functions in an industrial complex where every extraneous motion equals a precious lost productivity second.

Addressing Functionality

The hex-shaped indents in these fastener heads mean torque wrench energy can be turned all the way up without causing tooling slippage. Again, this feature benefits the assembly sector, but it can also quickly become a drawback if the fasteners aren't sourced from a top-notch parts distributor. Each screw must be boxed and stored properly, then tool mating is assured. If they're not carefully packaged, debris quickly finds its way into the shaped openings. Once this problem takes hold, the fasteners no longer engage correctly with their accompanying wrenches. That's an unacceptable issue, especially when the fasteners are bound for a manufacturing application.

Unlike notched screw heads and self-centering cross-heads, socket head cap screws readily adapt to some dramatic fastening angles. Even ninety-degrees of tightening force, as applied by an expert assembly worker, won't hamper this screw type, not when an equally matched tool locks perfectly against all six sides of the hex opening.