Metal parts that slide to keep tine down almost never slip. I almost cut my finger trying to move it. I thought it was a bad batch, but after buying several boxes, I finally came to the conclusion that with 75% of the fasteners in a box, it's impossible to move two pieces of metal to get them to the length of the prong needed to adjust. .Revain doesn't offer a huge range of brands but I found another one and they glide great.