In the industrial world, electronic components like standoffs and spacers can play a significant role in the overall functionality and longevity of various equipment. These mechanical hardware pieces are used to create space between two objects, often in electronic assemblies, to ensure proper alignment, positioning, and electric isolation. Their importance becomes even more pronounced when considering the materials used in their production. This article aims to guide industrial purchasers in making informed decisions about standoff and spacer material selection.
Understanding Standoffs and Spacers
Standoffs and spacers, though often used interchangeably, have distinct differences. Standoffs have threaded holes and are primarily used in PCB (printed circuit board) mountings to provide space between the PCB and the case, preventing electrical shorts. On the other hand, spacers are unthreaded and are typically used to separate two parts in an assembly.
Key Considerations in Material Selection
When selecting materials for standoffs and spacers, you should consider the following:
- Operating environment: The material should be able to withstand the conditions in which the spacer or standoff will be used. This includes factors such as temperature, pressure, moisture, and exposure to chemicals.
- Mechanical properties: Depending on the application, standoffs and spacers may need to withstand significant loads. Therefore, the material’s tensile strength, hardness, and fatigue resistance are crucial.
- Electrical properties: For electronic applications, the standoff or spacer material’s electrical conductivity or insulation properties will be a significant factor.
- Cost-effectiveness: While the material’s performance is essential, cost considerations should not be overlooked. The material should provide the best balance of performance and cost for your specific application.
- Availability: Selecting off-the-shelf material will save on lead time and cost. Not all materials are available in all sizes and configurations. Hence, we have provided more information on common materials in the next section.
Common Material Choices for Standoffs and Spacers
1. Metal: Aluminum, Brass, Steel, and Stainless Steel
Pros: Metal standoffs and spacers, particularly those made from brass, steel, or stainless steel, are known for their excellent strength and durability. They can withstand high temperatures and pressures, making them suitable for challenging industrial environments. Stainless steel standoffs are also highly resistant to corrosion.
Cons: Metal standoffs and spacers are more expensive than their plastic counterparts. They also conduct electricity, which may not be desirable in some electronic applications.
Let’s break this down further:
Aluminum: It is popular because of its ratio of weight to strength. It is light, non-magnetic, performs well in severe temperatures, and has insulating properties.
Brass: It is used in making high-quality standoffs. It is conductive, resists corrosion, and is non-magnetic. It is costlier and heavier than aluminum and is usually plated zinc or nickel. It can be soldered for grounding.
18-8 Stainless Steel: It is strong, conductive, and nonmagnetic. This stainless steel offers excellent corrosion resistance.
Zinc plated Steel: Steel is used for its strength, but it is heavier than aluminum and does not resist corrosion like Stainless steel, aluminum or brass. It is usually zinc plated for added corrosion resistance.
2. Plastic: Nylon
Pros: Nylon standoffs and spacers are lightweight, affordable, and resistant to most chemicals, making them a popular choice for many applications. They also offer electrical insulation, making them ideal for electronic applications. Most commonly available in Nylon 6/6, it is superlight, nonconductive, and resistant to chemicals and solvents. Nylon absorbs moisture, which can affect dimensions and other properties.
Cons: Compared to metal, nylon has a lower tensile strength and may not be suitable for high-load or high-pressure applications. It also has a lower maximum operating temperature.
Pros: Ceramic standoffs and spacers offer superior electrical insulation, even at high temperatures. They are also chemically inert and can withstand extreme environments.
Cons: Ceramic standoffs and spacers are more brittle than metal or plastic ones, making them susceptible to breakage under high loads or shocks. They are also typically more expensive and are often made to order, as they may not be available off the shelf.
In conclusion, the choice of standoff and spacer material should be guided by a thorough understanding of the operating environment and the mechanical and electrical requirements of your application. While cost is an important factor, it should not compromise the performance or safety of the assembly. Always consult with your supplier or an experienced engineer to ensure that you make the most suitable choice for your specific needs.
MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government. We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies. For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services. Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.