Why Shouldn’t I Use WD-40 on Everything?

WD-40 actually stands for “Water Displacement formula 40,” and while it can help loosen rusty bolts, the film of oil left behind isn’t nearly enough for good, long-lasting lubrication. You might find that the troublesome squeak subsides for a little while, but soon enough you’ll have to go spray it away again. Using the right lubricant the first time will ensure that the problem is solved long enough for you to forget all about it. Save the WD-40 for what it does best: light lubrication, cleaning, and freeing stuck-together Lego bricks.