dowelpin

A dowel pin, or dowelpin, is a cylindrical metal fastener used to locate or join parts in mechanical assemblies. Installed in precisely drilled holes, dowel pins provide accurate, repeatable alignment and are common in machine tools, jigs, fixtures, and cabinetry. They are typically not designed to bear high shear loads; instead they locate components during assembly and can be removed for disassembly.

Materials and forms: Dowel pins are made from carbon steel, alloy steel, stainless steel, brass, aluminum, and certain plastics. They come as solid pins for rigid, permanent alignment, or hollow pins for lubrication, oil passage, or easier removal. Common finishes include plain, heat-treated, or plated surfaces to resist corrosion.

Dimensions and fit: Pins are supplied in numerous diameters and lengths; the hole diameter and tolerance are chosen to provide either a press fit (interference) for permanent alignment or a slip fit for removable assemblies. Precision tolerances and proper cleanliness are essential to prevent binding or misalignment.

Installation and standards: Holes must be machined to tight tolerances and deburred before insertion. Pins may be press-fitted, tapped in, or lightly driven depending on the design. Dowel pins are manufactured to international standards (ISO, DIN) and national standards to ensure interchangeability.

Applications: Used to align components in machine tools, dies, molds, fixtures, automotive assemblies, and cabinetry. They enable quick disassembly and reassembly with repeatable accuracy.