The new Gunson Thread Gauge set (part no: 77106) enables identification of a large range of threads on bolts, set screws pipes and spark plugs. The gauges are manufactured from aluminium so they won’t damage fine threads and allow quick identification of bolt thread diameter, thread pitch or threads per inch.
Probably the most useful is the metric gauge, measuring thread sizes 2.5mm right up to 22mm and pitch of 0.45mm to 2.5mm. The pipe thread gauge measures sizes 1/16" to 1/2" with 14 tpi (threads per inch) to 27 tpi, and spark plug thread sizes 10, 12, 14 and 18mm.
Also included are two USS standard gauges which encompass SAE, UNC, and UNF standards, the smaller measuring sizes #5 to 3/8" with tpi from 16 up to 44 and the larger gauge measuring 1/4" to 3/4" and tpi of 10 to 28.