Gun Screw Thread Gauge , for sizes 4-40 4-48 5-40 6-32 6-40 6-48 8-32 8-36 8-40, Gunsmith. Here is a real timesaver. Tired of endless digging through boxes of screws? At least with this handy tool, you will know what size and thread you are looking for. Screws for illustration and are not included. Condition is New. Shipped with USPS First Class. Thanks