OP here. I can't believe the amount of energy I had to expend to solve this simple problem, but a Google search yielded many people with similar issues. In case anyone finds themself in this situation, Strosniders in Bethesda will cut it for $6 (for both pieces) but my neighbor with a hacksaw did it in a minute. It seems like a ridiculous solution to a product people buy daily, but oh well, it's solved now.

I recently moved into a house with a built-in kitchen desk area. The bottom drawer has brackets for a hanging filing system. However, the length is 20". Iat the recommendation of a store clerk, I just bought a system at Staples that is 24-28", with perforations beginning at 24" (to cut the frame with pliers, as per the box's instructions). I have no way to cut the frame at 20", as it's steel with no perforations. The only other sets I'm finding in stores and online max out at 18" long. Has anyone experienced this? Is there another item that will work in the existing brackets? Is my best bet to cut the steel hanging frame? If so, how do I do it since there are no perforations where I need to cut? Do I take it to Home Depot? Thanks.