I would go back to Lowes and buy the thread gauge for about $6.00.I went to Lowe's and HD and tried using the board they have to screw them in and find the correct size. The DP is 1/2"-13, but they were both sold out of all the sizes. The Players would not screw into anything, not even the metric sizes. If I had to make and educated guess, it's something like 1/2"-10(?)