What Are the Flexible Spring Tabs on the Side of Computer Cases For?

If we need to remove the side panel on our desktop computers, we usually do not give much thought to the series of flexible spring tabs around the outer edge of the case, but what are they actually there for? Today’s SuperUser Q&A post has the answer to a curious reader’s question.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

The Question

SuperUser reader VAN wants to know what the flexible spring tabs on the side of computer cases are for:

Many computer cases have these holes/cut-outs/tabs on the outer edge of the frame. What are they for?

What are the flexible spring tabs on the side of computer cases for?

The Answer

SuperUser contributor VAN has the answer for us:

The flexible spring tabs are definitely made to reduce gaps around the outside of the computer case and provide better grounding, both of which reduce EMI emissions. The relevant patents covering the chassis and peripheral cages discuss the “feature”.

Here are some additional references that support the dampening idea/theory as well. Although they are not for the chassis per se, one patent covering media drives mentions vibration dampening and a second patent for a hard disk frame mentions both uses.

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users?