August 20, 2014
What the heck are Standoffs and Spacers?
We close out the summer of 2014 by introducing you to Standoffs and Spacers. According to the dictionary, a Standoff is defined as “a stalemate or a deadlock between two equally matched opponents.” In the world of manufacturing and assemblies, Standoffs, and their cousin the Spacer, have a different meaning which we will uncover today.
What are Standoffs and Spacers?
Often classified as Electronic Hardware, or Panel Hardware, Standoffs are hex or round shaped fasteners which have a body and two threaded ends. The threaded ends can either be an internally threaded opening (female) or an externally threaded post (male). They are commonly used to mechanically support and electrically connect and position components within assemblies.
Spacers are similar to Standoffs, however, Standoffs are threaded on both ends, and Spacers are unthreaded with an inside clearance hole.
Who uses Standoffs and Spacers?
Look inside an assembled circuit board, and you will be greeted by Standoffs and Spacers, because in the world of Electronic Hardware, they are the standard for connecting and mounting circuit boards, panels, doors, and gears. Both are commonly used to properly position parts within an assembly, to reduce component contact, to elevate stacked sections, to ensure enough room for heat to dissipate, and to separate or create space between two objects. These guys are workhorses!
What do I need to consider when selecting Standoffs and Spacers?
Standoffs and Spacers are available in a variety of styles based on four main attributes: 1) shape 2) outer diameter of the body 3) body length and 4) thread size or clearance hole. Standoffs have a fifth attribute, thread type (we like to call it gender), as defined below.
Standoffs and Spacers can be hex, round or square shaped. The most common diameter of the body is ¼, but many other sizes are available. Standard body lengths range from ¼ x 2″. Clearance holes and thread generally range from #2 through ¼. Special lengths and sizes are available – just ask!
Standoffs come in three main styles (genders):
1) Female-female: can be fully threaded or partially threaded on each end.
2) Male-female: have internal female threads on one end and male threads on the other. Threads are generally the same size.
3) Male-male: have external threads on both ends which may be of differing thread size.
What Materials are available?
Common materials include aluminum, brass, plastic/nylon, steel, and stainless steel. Common platings include clear anodized, nickel, gold iridite and zinc plated. There are over 20 common plating’s available! Here are some of the most common materials:
Aluminum 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 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 is strong, conductive, and nonmagnetic, this stainless steel offers excellent corrosion resistance.
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 often zinc plated for added corrosion resistance.
Nylon 6/6 is superlight, nonconductive, and resistant to chemicals and solvents. Nylon absorbs moisture, which can affect dimensions and other properties.
Lesson Learned, considerations when selecting and using Standoffs and Spacers
- Standoffs are sometimes referred to by their brand names, which can often be substituted by generic equivalents. Popular brands include: Amatom, Concord, Globe, H.H. Smith, Lyn-tron, Microplastics, Keystone, Pem, RAF, Unicorp.
- To measure a Standoff or Spacer, measure the outside diameter of the body, the length of the body and the thread size. Determine if the standoff is a female-female, male-female or male-male. A typical Standoff might measure as follows: 1/4 hex X 1/2 long X 8-32 thread male-female aluminum standoff. This exact standoff is made and branded by at least 10 manufacturers. Note: the length of the male threaded post is standard and is not called out.
- Standoffs and Spacers sometimes show up under their Mil-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series include NAS42, NAS43, NAS61, NAS1056, NAS1057, NAS1829, NAS1830, NAS1831.
Standoffs and Spacers at MF Supply
Here at MF Supply, we supply some of the most common and unusual Standoffs and Spacers, including:
- The full range of commercial and mil-spec parts in both inch and metric.
- Specials sizes, materials and platings. Just try to stump us!
- We are authorized distributors for Amatom, Concord, Lyn-tron, Microplastics and RAF and offer the full range of brand names and equivalents.
For more detailed information, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1832
And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!