holkiliitin

Holkiliitin is a type of mechanical fastener used to connect a hub, sleeve or bushing (holkki) to a shaft or to another component through a retained joint. The concept combines a cylindrical element (the holkki) with a retaining feature (liitin) such as a pin, screw, or cotter that prevents axial movement and can also help transmit torque in the assembled part.

Designs of holkiliitin vary. Common configurations include a sleeve that fits into a bore and is retained by a through hole and pin, a press-fit or interference-fit sleeve combined with a set screw or threaded fastener, and versions that rely on a cotter pin or locking pin for retention. The joint is typically chosen for ease of assembly and disassembly, reliable axial positioning, and adequate load transmission, depending on the specific design.

Materials and manufacturing methods are standard for mechanical couplings. Holkiliitin components are frequently made from steel (including alloy and stainless variants), with brass or aluminum used for lighter-duty applications. Finishes may include plating or nitriding to improve wear resistance. Manufacturing processes usually involve turning and milling for precision fits, followed by heat treatment to achieve the required hardness. Tolerances are selected to provide the intended interference or sliding fit, depending on whether the connection is designed for easy removal or a tight, wear-resistant joint.

Applications include machinery couplings, pulley hubs, machine tool spindles, agricultural and industrial equipment, and modular assemblies where a compact, replaceable joint is advantageous. Routine maintenance focuses on wear inspection, proper lubrication, and ensuring that retention features are intact to prevent loosening or unintended disassembly. See also: mechanical fastener, pin, bushing, coupling.