I installed a carbide work box on my welding trailer. It doesn't come with a latch. I bought these and assembled them with nuts and bolts. The hook mount has 2 holes that need to be closed to use 2 screws. I understand that you inserted and tightened the first one. Then insert the second bolt by adding three lock washers that position the nut over the other nut allowing the second nut to be tightened. Clamps like normal but not heavy. Once installed they seem to work fine. I used 1/4 x 1" screws.