I want to install some multi-functional boards on the printer shelf where I store my frequently used tools.

It's not feasible to use fasteners because I don't have the right tools.

This ingenious small mounting bracket is actually just three multi-functional snap-fit mounting bases placed side by side, with two lugs on the back that can be installed into the safety pin holes on the shelf legs.

The shelf is fromhttps://shelvingpro.com.au/

But I've seen similar medium-sized shelves from other brands, and they seem to use the same frame, so they might be compatible. Check the pictures with the hole sizes for more details.

The hole size is 8mm x 12mm

To install it on the shelf column, you need to tilt the component to first insert the top of the lug, and then use the top edge as a pivot to rotate it downward.
They are very tight to install, but once they are in place, it's hard to remove them again.