I decided to buy some metal spring clamps as the plastic (not Irwin) clamps I have break too easily. I decided that Irwin brand spring clamps would be a good choice given the quality Irwin bar clamp I have. (I can't believe the hardness of the stem metal. Even the cobalt-coated drill bits couldn't pierce it when I tried to make a larger hanging hole.) The spring in these 1-inch clamps is pretty strong, which is what I need. I use some of these to keep the wind from blowing off the tarp etc. I haven't used them long enough to know how well the metal finish and pads stand up to the elements, although that's not a huge issue for this type of utility.
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