Dowel pins are industrial fasteners that are used to join two or more items together. They are commonly available in imperial or metric units. They also maintain precision alignment, ease insertion, absorb hole tolerances, and prevent interlocking. Hollow alignment dowels reduce weight and cost, plus simplify assembly. For a firm fit, the hole should be exactly the same size or slightly smaller than the dowel's diameter. dowels are commonly used in furniture. They can also be applied as hinges and simple axles. They are short, cylindrical rods made of various materials including wood, metal, and plastic. Dowel pins can be tapered, slotted, grooved, or otherwise altered to change their mechanical properties. They are commonly available in imperial or metric units.