Product Description. Very handy gage to quickly determine the pitch of various threads. Made of high quality polished tool steel. Features a locking device at both ends to securely lock the leaves. All leaves clearly marked with size. Comes in a plastic pouch. Pitches included: Whitworth Standard 55° Threads - 4G, 4 -1/2G, 5G, 6G, 7G, 8G, 9G, 10G, 11G, 12G, 13G, 14G, 16G, 18G, 19G, 20G, 22G, 24G, 25G, 26G, 28G, 30G, 32G, 36G, 40G, 48G, 60G, 62G.