Basic Information

Posts, spacers and standoffs are threaded components used in applications where boards, plates, or other items need to be fastened to each other. Posts, spacers and standoffs are often used in the assembly of printed circuit boards (PCB), and sometimes sold in kits. They are often used in combination with other fasteners.

Selection Criteria

Selecting posts, spacers and standoffs requires an analysis of application requirements and performance specifications.

• Materials can be conductive or non-conductive.
• The material should be able to withstand varying degrees of heat, humidity and vibration.
• Male standoffs, female standoffs, and swage spacers are commonly available.

Binding Posts

A binding post is a device that allows a wire to be connected to an electrical circuit board or electronic device.

Posts usually consist of:

• A metal post 
• A plastic, polycarbonate, or metal head

A series of washers and nuts are used to secure the wire to the board.

Spacers

A spacer is used as a bushing or where an unthreaded rod or threaded screw needs to pass through.

Spacers come in a variety of configurations, including:

• Round or square
• Locking
• Self-aligning
• Stacking
• Telescoping

Standoffs

A standoff is used to elevate stacked sections, allowing for space between them to secure wires or other connections.

Standoffs and spacers are usually made of materials that allow wires to pass around them without interfering with the wire’s insulation.

Swaging

Posts, spacers and standoffs can be part of an assembly that is secured using a cap or nut and a swaging tool. A swaging tool presses or bends the cap or nut onto the threads of a post or pin, securing the cap into the grooves. Swaging is also used to compress materials around a die into a particular shape.

Bullet swaging is a from of swaging that uses a high pressure press to flow bullet materials such as solid or powdered metals around high precision dies.

Standards

A-A-59555 - Post, binding, electrical, waterproof (insulated), top entry

MIL-P-55149 - Posts, binding, electrical (insulated and uninsulated)

NAS192 - Posts, binding, terminal board, electrical

MIL-C-28754/18 - Connectors, electrical, modular, spacer, pin, type IV, single span

NAS1129 - Standoff, threaded, self-clinching

Resources

Image Credits:

Spirol International Corporation | Ark-Plas Products, Inc. | Daburn Electronics & Cable