I second Harbor Freight for their F clamps. As far as quality goes, no their not the best, but I haven’t had one fail yet. Only negative is the lack of acme threads, which, I don’t really see a need for. Just don’t get any plastic clamps from HF, as they break the first time you use them! I also have their aluminum bar clamps and those are also good for the price. I will say that the spring clamps are not the best deal in the world, as the ones from HD are less expensive surprisingly. I have HF, Bessey, and Jorgensen clamps, and most of the time, I’m reaching for the HF’s.