Hand tap set, ≈ DIN 352, HSS-G, BSW 5/16 x 18 

for general use - non abrasive material up to 900 N/mm² - unalloyed and low alloyed steel - for through and blind holes - for thread cutting by hand Thread type: Whitworth-thread BS 84 Norm: ≈ DIN 352 Material: HSS-G