Mechanical assembly is to attach two (or more) parts together with mechanical methods.

uses discrete hardware components with external or internal threads for assembly of parts.

Screw is an externally threaded fastener that is generally assembled into a blind threaded hole.

Self-tapping screws: posses geometries that permit them to form or cut the matching threads in the hole.

Bolt is an externally threaded fastener that is inserted through holes in the parts and screwed into a nut on the opposite side.

Nut is an internally threaded fastener having standard threads that match those on bolts of the same diameter, pitch, and thread form.

Rivets are widely used fasteners for achieving a permanent mechanically fastened joint.

Rivet is an unthreaded, headed pin used to join two (or more) parts by passing the pin through holes in the parts and then forming a second head in the pin on the opposite side.

Five basic types:

a). Solid, b). Tubular, c). Semitubular, d). Bifurcated, and d). Compression.

Eyelets are thin-walled tubular fasteners with a flange on one end, usually made from sheet metal. They are used to produce a permanent lap joint between two (or more) flat parts.

Used in low-stress applications to same material and cost.

Press Fitting: is one in which the two components have an interference fit between them. Such as a pin is pressed into a hole of slightly smaller diameter.

Functions: 1). locating and locking the components; 2). Permitting one part rotating around the other.

Shrink and Expansion Fits: is to assembly two parts together by altering part temperatures. the external part is heated to enlarge it thermal expansion, and the internal part either remains at room temperature or is cooled to contract its size.

Snap Fits: involves joining two parts in which the mating elements posses a temporary interference while being pressed together, but one assembled they interlock to maintain the assembly.

Retaining ring: is a fastener that snaps into a circumferential groove on the shaft or tube to form a shoulder. It is used to locate or restrict the movement of parts mounted on the shaft.

Stitching: is a fastening operation in which a stitching machine is used to form the U-shaped stitches one at a time from steel wire and immediately drive them through the two parts to be joined.

Stapling: preformed U-shaped staples are punched through the two parts to be attached.

Sewing: involves the use of a long thread or cord interwoven with the parts so as to produce a continuous seam between them. It is used for soft, flexible parts such as cloth and leather.

Created by Dr. Wang