Lock Nuts
Keps nuts, also known as K-lock nuts, are hybrid fasteners that feature a free-spinning external-tooth, conical, or flat washer permanently attached to a standard hexagonal nut. When torqued against a bearing surface, the integrated washer's serrations aggressively bite into the substrate, generating high frictional resistance against rotational loosening while eliminating the handling of loose washers. They are predominantly utilized in high-volume light-to-medium duty assemblies, electrical panel grounding, and sheet metal fabrication where rapid installation and basic vibration resistance are required.
Keps nuts, frequently known as K-lock nuts or captive washer nuts, are innovative hybrid fasteners that feature a free-spinning washer permanently attached to a standard hexagonal nut. This attached washer can be an external-tooth, internal-tooth, conical, or flat design. When the nut is torqued against a bearing surface, the integrated washer's teeth or conical profile aggressively bite into the substrate. This generates high frictional resistance against rotational loosening while entirely eliminating the tedious handling of loose washers during assembly, drastically streamlining production workflows.
To perform effectively across various environmental conditions, Keps nuts are forged from resilient materials. Stainless Steel (including grades A2 and A4) and Carbon Steel are the most prevalent, offering an excellent balance of strength and cost-effectiveness. For highly corrosive or extreme-temperature environments, specialized alloys such as Monel 400, Inconel, and Hastelloy are utilized.
The longevity and aesthetic integration of these fasteners are bolstered by multiple finish options. Zinc Plated and Hot-Dip Galvanized finishes provide robust defense against oxidation. Alternative finishes like Nickel-zinc plating, Black Oxide, Natural, and Passivated treatments ensure that the fasteners meet specific industry regulations regarding corrosion resistance and surface conductivity.
Keps nuts are manufactured under strict dimensional and material guidelines to ensure their locking mechanisms perform reliably. Key standards include ASTM A563, which dictates the mechanical and chemical requirements of the nut body, and ASTM F812, which establishes critical limits for surface discontinuities to ensure structural integrity.
The core locking mechanism relies on washer teeth friction or conical spring tension. The permanently attached washers come in several types, including external tooth lock washers, internal tooth lock washers, and plain flat washers. Depending on the application, the design may incorporate a star-type washer, a conical washer, or a standard flat washer. Thread compatibility is extremely broad, adhering to Thread Standards such as ISO 261, ANSI, and ASME B1.1, and covering Metric, Unified National Coarse (UNC), and Unified National Fine (UNF) thread types.
The integration of a captive washer makes Keps nuts exceptionally well-suited for high-volume, light-to-medium duty assemblies where rapid installation and fundamental vibration resistance are required. They are predominantly utilized in sheet metal fabrication and automotive manufacturing, where they prevent loosening caused by operational vibrations. Additionally, they are standard components in electrical panel grounding, robotics, and consumer appliances, providing a secure, vibration-resistant joint without the need for complex, multi-part fastening systems.
Our keps nuts 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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