Lyn-Tron's Comprehensive Buyer's Guide to All Things Spacers

Spacers are used to maintain space between 2 objects in an assembly. In the world of Electronic Hardware and Electronic Components, spacers are most often found spacing circuit boards, motherboards, control panels and doors. Spacers come in a wide variety of shapes and materials while being easily found in both inch and metric sizing. For a more permanent installation option, Swage Type Spacers can be permanently affixed in place.


Standard Spacer Metric Spacer

Spacers are used in a variety of applications, but originally were created and designed for use as hardware in electronic equipment such as computers, test equipment, and handheld devices. Even though this electronic hardware was going into a variety of devices, some standard dimensions became obvious. For example, screws were the preferred method of installing and holding the spacer in place. As a result, the Spacer’s through-hole became standardized around common screw thread sizes. This allowed for spacers to be compatible with other Off-the-Shelf Hardware and made it easy for engineers to quickly add spacers into their designs. In addition, Manufacturers could easily produce a large variety of size combinations. You can now order a spacer in a nearly endless assortment of Outside Diameters, Inside Diameters, Lengths, Materials and Platings. With so many different spacer combinations available, their use quickly spread to other industries as well. They are now found nearly everywhere and are used as bushings, bearings, washers, tubes, sleeves, frame supports, etc.

Selection Guide

While your application may dictate a different order, this is the most common path to selecting the perfect spacer.

  • Step 1 - Spacer Type
    • Based on the installation method, choose between the standard Spacer or the Swage Spacer.

The most common spacer type and used in most situations. These can be installed with just a screw and nut. Quick and easy to install, versatile in it’s uses, and able to be removed in the future.

Swage Spacers

Great for high volume and automated production. The swage spacer has a swage end that can be inserted into a through hole in the board and be swaged into place (like riveting). The part will not move around while waiting for final assembly. Swage spacers come in common sizes to fit standard circuit board thicknesses and drill hole sizes. Installed using a punch and anvil to swage the part into place.

  • Step 2 - Inner Diameter (ID)
    • The Inner Diameters offered are designed so standard male screw threads can fit through without interference. This type of fit is called a clearance fit and why the ID can also be referred to as a “Clearance Hole”. You can filter through available spacers based on the “Screw Size” (eg. #4, #10, M3, M6) and review all the spacers that fit your screw. Review the standard options available below.
Screw Size Spacer ID Code Clearance Hole Range (Inch)
#0 00 0.062"-0.072"
#2 02 0.088"-0.098"
#4 04 0.114"-0.124"
#6 06 0.140"-0.150"
#8 08 0.166"-0.176"
#10 10 0.192"-0.202"
#12 12 0.218"-0.228"
1/4" 25 0.252"-0.262"
5/16" 31 0.315"-0.325"
3/8" 38 0.377"-0.387"
Screw Size Spacer ID Code Clearance Hole Range (Metric)
M1.6 16 1.67mm-1.93mm
M2 20 2.07mm-2.33mm
M2.5 25 2.57mm-2.83mm
M3 30 3.07mm-3.33mm
M3.5 35 3.57mm-3.83mm
M4 40 4.07mm-4.33mm
M5 50 5.17mm-5.43mm
M6 60 6.17mm-6.43mm
M8 80 8.37mm-8.63mm
  • Step 3 - Outer Diameter (OD)
    • For any ID, you may also consider going with a larger or smaller Outside Diameter to create a thick spacer or a thin spacer.   
      • - A Large OD creates a thicker spacer and is an easy way to add strength. The larger OD spacers will resist bending or warping during installation compared to a smaller OD. In addition, the Large OD provides added surface area where the board and spacer meet. This will reduce any potential for indentation or other damage on soft or delicate materials.

      • - Smaller OD’s form a thin spacer and are perfect when space and weight are the primary concern. Choosing a smaller OD will decrease the footprint of the spacer and allow added room for other components, while reducing the overall weight of the part. 
Outside Diameter Tolerance
Inch 1/8" (0.125") - 1-1/4" (1.250") ±.005
Metric 4.5mm - 32mm ±.13
  • Step 4 - Length
    • Spacer Lengths are made true to size and held to a precise tolerance of +/-0.005 inch or +/- 0.13mm. To avoid needing multiple parts to fill up the distance between boards, many different lengths are readily available. Measure the distance between boards and find the length that matches up.
Overall Length Range Tolerance
Inch 1/8" (0.125") - 2" ±.005
Metric 3mm - 51mm ±.13
  • Step 5 - Profile
    • Profile – Round Spacers are the most common, but Hex and Square shapes are also available. The Hex and Square profiles offer flat sides for a variety of purposes, but can also serve as an easily-recognizable, visual cue to differentiate similar components during high-volume installation.

  • Step 6 - Material & Plating Options
    • When deciding on a material and plating/finish, there are many properties that can be considered. The most common ones include Corrosion and Rust Resistance, Magnetism, Electrical Conductivity, Strength to Weight Properties, Color, and Cost. Review the chart below to see which standard material has the right properties for your application’s environment.  For an explanation of RoHS, Conflict Minerals, WEEE and REACH visit our Technical section.

Materials Corrosion Resistance Magnetic Electrical Conductor Strength to Weight Color Plates
Stainless Steel High Slightly Yes - Poor Above Average Grey Available
Steel Low Strongly Yes - Poor Average Grey Available
Aluminum Average No Yes - Average Very Above Average Grey Available
Brass High No Yes - Below Average Average Yellow Available
Nylon High No No Average White and can be dyed to other colors No
  • More Questions?
    • Lyn-Tron has been the leading manufacturer of Electronic Hardware for over 50 years! We offer a full line of standard Electronic Hardware, but will manufacture custom sizes and OEM designed hardware to your print. Contact us today with any requests for Electronic Hardware or custom parts manufacturing.