Roymech engineering encyclopedia

Joining Processes

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Joining Processes


This topic describes methods of joining parts together to form assemblies which provide useful mechanical functions.  At its most basic level joining can include such wonderfully simple methods as sewing(with cotton thread ), paper clips, press studs, zips, buttons, shoe laces.  A responsible engineer should consider all options when brain storming for fastener solutions.  Again joining processes include bricks and mortar, wood joints, wood pegs, fitting used to assemble kitchen and bedroom funiture.

Certain early boats i.e coracles are assembled by weaving twigs to form the frame which is covered by animal skins fastened using stitched (sewed) joints.   These craft are still used with great success in many areas of the UK.

Historically wooden pegs (dowels) and adhesives are probably among the first engineered joint technologies used by man as used for wooden structures, vehicles, and water borne craft.  Mechanical structures which are hundreds of years old are still to be found which have been assembled using these methods. ( Water wheels).

The cast iron bridge at Ironbridge in Shropshire UK was mainly assembled using dove-tailed joints.

Metal rivets have been used for nearly along as metal has been used by man.    Body armour is often assembled using rivets.  Riveting hast been the most important joining technology for metals, until the introduction of welding.   In recent times since the start of the twentieth century welding has been the most important joining process for metal structures, vehicles and ships.

For machines and structures which have to be assembled and disassembled, fasteners using screw threads are the most important components.   These include pipe connection, screws, and bolts.

Initially engineering joining methods can be broadly classified into two main groups.

1) Permanent.
2) Non-permanent based on removable fasteners

Typical members of each group are included in the following lists

Press Fit joints
Adhesive.(Semi permanent)
Removable Fasteners
Permanent Joints

Notes on welding are to be found on webpages..... Welding ....... Weld Strength
Notes on Rivets are to be found on webpages..... Rivets
Notes on Adhesives are to be found on webpages....Adhesives

Non-Permanent Joints

Notes on bolts and screws are to be found on webpages..... Screws Index
Notes on keyways are to be found on webpages..... Keyways Index
Notes on Pins are to be found on webpages..... Cotter Pins...Taper Pins
Notes on Circlips are to be found on webpages..... Circlips Index

Links Providing information on Joining
  1. Fastener Design Manual.. A comprehensive two part manual on design- very useful
  2. Fastener Technology .. A trade Magazine
  3. Pivot Point Fasteners ... A site devoted to non-threaded fasteners
  4. Assembly ... The assembly technology resource centre
  5. Velco ..Innovative Joining solutions
  6. Permabond..Industrial Adhesives