The Missing Standard: Is there a GB National Standard for Male-Female Standoffs?
The “Ghost” Standard in the Fastener World
If you are an engineer in the electronics, PC chassis, or cabinet assembly industries, you are undoubtedly familiar with the Male-Female Standoff (colloquially known in China as the “Yin-Yang Screw” or Hexagonal Standoff). It is ubiquitous, serving as the backbone for PCB mounting and component spacing.
However, when quality control engineers or procurement specialists attempt to locate the official Chinese National Standard (GB) number for this specific part to include in their BOMs or inspection sheets, they hit a dead end.
The reality is: There is currently no specific National Standard (GB) for Male-Female Standoffs in China.
From a standardization perspective, this is arguably a significant “bug” or gap in the system, considering the massive volume of these components used annually. Unlike standard bolts (GB/T 5783) or nuts (GB/T 6170), the hex standoff operates in a regulatory grey area.
Why is there no standard? (An Industry Insider’s View)
As experts at Ever Power, we have looked into this extensively. I once personally submitted a proposal to the China Machinery Industry Standardization Institute, suggesting the drafting of a specific standard for hex standoffs. Unfortunately, the proposal did not gain traction at the time.
The reason likely lies in the highly customizable nature of the electronics industry. Standoff lengths vary by the millimeter to accommodate specific PCB layers, making a single rigid standard difficult to implement universally compared to general structural fasteners.
The Ever Power Solution: Our Internal Standardization
Since the national body has not defined the rules, the industry must regulate itself. To ensure consistency for our clients, Ever Power has codified our own internal standards based on international best practices and common market usage.
You can reference our internal specification sheet here:
Ever Power Internal Specification: Male-Female Standoff Dimensions
Note regarding usage: While we strictly adhere to these dimensions during manufacturing, this is an Enterprise Standard, not a National Authority Standard. We recommend using this as a design reference when your project does not require highly customized, non-standard dimensions. It provides a reliable baseline for “off-the-shelf” availability.
Visual References
1. Male-Female Hex Standoff (The “Yin-Yang” Screw)
Features one internal thread end and one external thread stud.
2. Female-Female Hex Standoff
Features internal threads on both ends (Spacer).
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