Screw size for your towel bar door handle

The 10-138 and 10-133 have an 8-32 machine thread, so you want to use a screw in that size. Length depends on what you had originally, though. I recommend taking one of the old screws to a local hardware store to have them match it up if at all possible. Otherwise you may need to try a few different lengths out until you find the right one.