The Groz Grease Fitting Thread Tester is a great toolbox accessory for sorting out mixed fittings. Its aluminium construction with mounting holes helps to segregate around 21 most popular thread-type fittings:

1. Metric (M6 x 1, M6 x 0.75, M8 x 1, M8 x 1.25, M10 x 1 & M10 x 1.5)
2. NPT (1/8”, ¼” & 3/8”)
3. BSPT (1/8” & ¼”)
4. UNF/ANF (1/4”, 5/16” & 3/8”)
5. BSW ( ¼”, 5/16”, ½” & 3/8”)
6. BSF (3/16”, ¼” & 5/16”)