Porausreiän

Porausreiän is a drilling hole produced by removing material with a drill, typically cylindrical in shape and defined by its diameter, depth, and the position of its axis. In engineering practice, a porausreiän can serve as a clearance hole, a through hole that passes completely through the workpiece, or a blind hole that ends before exiting the far side. Variants include countersunk holes for flush screw heads and counterbores that provide a stepped seating for fasteners or other features.

Manufacturing and finishing often involve several steps. A drill bit removes material to create the initial hole, and a pilot hole may be drilled first to guide a larger bit. For higher precision, reaming or boring can be used after drilling to improve dimensional accuracy and surface finish. Deburring and chamfering are common finishing operations to remove sharp edges and facilitate assembly. Drilling conditions, such as speed and feed, depend on material properties (metal, wood, plastic) and tool geometry. Proper workholding and lubrication or cooling can affect hole quality and tool life.

Quality and measurement focus on the hole’s size, straightness, and perpendicularity to the work surface. Typical inspection methods include bore gauges, micrometers, calipers, and, for complex features, coordinate measuring machines. Holes are specified with a diameter and depth, and may carry additional tolerances or positional requirements, especially in assemblies requiring precise alignment.

Applications of porausreiän include fastening components, mounting bearings, creating passageways, and enabling access for fasteners or lubricants. A range of drill tools and finishing tools—such as twist drills, center drills, Forstner bits, and reamers—are used to produce and refine porausreiäns across materials.