I have a Black and Decker workbench, is similar to the Keter workbench but the opening for the clamp slots is much smaller (about ⅓ or 8 mm), so I wanted to adapt the ideas of https://www.thingiverse.com/thing:4846617 and https://www.thingiverse.com/thing:4057857 to use on my Workbench.
Just add a ¼ inch bolt (secure it with some glue) and you are good to go. you can use the top portion of the original design to secure tools, or something like https://www.thingiverse.com/thing:2841271 to clamp other items.
How to use it
To install the original metal clamp for the B&D workbench you have to insert the end on the opening, then slide it in the channel and then swing the clamp down until it fits all inside the slot (pushing the handle to lock it emplace)
the part I designed works similarly.
I has 2 pins one next to the body and the other a bit further apart.
You insert the further pin into the opening, then move the assembly along the channel until the second pin is aligned to the opening, swing the assembly to insert the second pin and then you can move it anywhere in the slot that you need and wont come out of the channel.
to Remove you do the opposite, move the assembly to the end so the second pin can be removed from the channel, incline the assembly a bit and slide a little more so the further pin is aligned to the opening and can be removed.
I'm including some images showing the step by step, (I took the pictures w/o the Bolt so the part can bee seen clearly, but you would put the bolt on before using it).
I printed all in a cheap PLA that I had in the printer, 3 walls, 20% infill, and I expect to last a long time (we will see)
NOTE: the design and STL is in the “use” position, but if you flip it upside down you can print it w/o any supports.
The author remixed this model.
adapted to the B&D workbench, dual pins for better security