What Is a PCB Standoff? Types and Selection Criteria
A PCB standoff is a nylon support that holds an electronic board at a set height above a panel, box or device housing and insulated from it.
A PCB standoff (PCB support, board spacer) is a plastic support that holds an electronic board at a set height above a mounting plate, box base or device housing and leaves an insulation distance between the board and the surface. It keeps the solder points on the underside of the board from touching a metal surface and leaves space under the board for air circulation and cable routing. It is used to fix control boards, relay and drive boards inside panels and devices.
Selection criteria
- Height: Chosen by the clearance needed for the longest component lead, solder points and cable routing under the board. The KSN models in the catalog are 24.5 mm, 26.5 mm, 27 mm and 30 mm high.
- Mounting hole: The product data gives a bottom hole diameter of Ø4.5 mm for the KSN-08-1008 and Ø4.8 mm for the others. Drill the hole in the mounting surface to this size; check the board-side hole size on the product drawing.
- Material: The product data gives nylon 6.6. Nylon is insulating and separates the board electrically from the housing; at hot spots, check the material's temperature limit in the datasheet.
- Quantity and pack: The KSN-08-1008 comes in packs of 500 and the other models in packs of 250. Allow for the number of supports each board needs (usually one per corner).
Common mistakes
- Choosing a support that is too short: Long-leaded components or solder points under the board touch the metal surface and create a short-circuit risk.
- Not checking the hole diameter: In a large hole the support does not hold; in a small hole a forced support cracks.
- Fixing the board at only two corners: The board flexes and solder points crack under vibration; support the board at every corner.
PCB standoffs at Welibaba
The PCB Standoffs category has 4 active products from KSN, all listed with prices:
| Model | Height | Bottom hole diameter | Pack |
|---|---|---|---|
| KSN-08-1008 | 24.5 mm | Ø4.5 mm | 500 pcs |
| KSN-71-1071 | 26.5 mm | Ø4.8 mm | 250 pcs |
| KSN-70-1070 | 27 mm | Ø4.8 mm | 250 pcs |
| KSN-72-1072 | 30 mm | Ø4.8 mm | 250 pcs |
Other mounting parts are in the Fastening and Mounting Elements category and explained in the fastening and mounting elements guide.
Frequently asked questions
What does a PCB standoff do?
It holds an electronic board at a set height above its mounting surface and insulated from it; it keeps solder points off the metal surface and leaves space under the board.
What height of support should I choose?
Allow a margin above the longest lead and solder point under the board. If cables pass underneath or air circulation is needed, choose a taller model.
How many supports does a board need?
Usually one at each corner; on large boards or boards with heavy components, an extra support is added in the middle.