Allen Screws
Grub screws, also known as set screws, are headless fasteners that provide radial holding power by driving their threaded body entirely into a tapped hole to exert compressive force against a mating shaft. Available with specialized tip geometries—such as cup, cone, flat, or dog points—they offer varying degrees of surface penetration and vibration resistance. They are critical in mechanical power transmission systems, commonly securing gears, pulleys, and collars to rotating shafts without the bulk of a protruding fastener head.
Grub screws, also commonly referred to as set screws, are highly specialized, headless fasteners designed to provide radial holding power. Rather than relying on a traditional head to clamp two materials together, these fully threaded cylinders are driven entirely into a tapped hole. An internal hex (Allen) drive allows them to exert compressive frictional force directly against a mating shaft or component. This unique mechanism allows them to secure parts without a protruding head, making them indispensable in mechanical power transmission systems and assemblies with strict spatial constraints.
Given the high compressive forces they must exert, Grub Screws are manufactured from exceptionally hard and durable materials. Options include high-tensile Carbon Steel and Alloy Steel for maximum grip, alongside Stainless Steel, Brass, and Titanium for specialized applications requiring corrosion resistance, non-magnetic properties, or high strength-to-weight ratios.
To enhance longevity and prevent galling, these screws are treated with various finishes:
Grub Screws are defined by their unique point styles and adherence to precise engineering standards.
The primary function of Grub Screws is to secure rotating components within mechanical power transmission systems. They are widely used to lock collars, gears, pulleys, and sprockets firmly onto rotating shafts, preventing unwanted axial or rotational slippage. Because they are driven flush or below the surface of the workpiece, they are perfect for blind holes and moving parts where a protruding head would cause interference or safety hazards. Different point styles dictate their specific use; for instance, cup points provide superior bite into the shaft, while flat points are used when frequent adjustments are necessary without marring the mating surface.
Grub Screws are essential, high-performance fasteners that deliver unparalleled radial locking strength in a compact, headless design. With a wide array of specialized point styles and robust material grades, they provide engineers with a precise and reliable solution for shaft locking and mechanical power transmission applications.
Our grub screws are available in a range of sizes, materials, and standards. Contact us for a detailed specifications sheet and competitive bulk pricing.
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