8pc WHITWORTH COMBINATION SPANNER SET
Professional Cr-v Satin Finish Steel
Quality Combination Set with an Open End &Ring
1/8" 3/16" 1/4" 5/16" 3/8"
7/16" 1/2" 9/16"
With British Standard Whitworth (Whit) or BSF the spanner or socketmight carry the markings for two sizes for example 7/16inch whitworth and 1/2 inch BSF.This means the tool will fit nutsand bolts with those thread sizes.Sometimes only one standard will be marked onthe spanner but a 7/16 whit will always fit a 1/2 bsf and all through the rangethe spanners are will fit both standards always one size apart so you only needone set of spanners to do both! British Standard Whitworth incidentally was oneof the first attempts at a standard or universal thread and is named after theBritish engineer who invented it,BSF stands for "British StandardFine" it is in effect the fine version of Whitworth.Thread guages whichlook a bit like a miniature saw blade are the easiest way to identify thedifferent threads,a lot of bolts are marked but it's almost impossible to listall the markings that have been used by different manufacturers over theyears.A spanner or socket should fit snugly on a nut or bolt in good cleancondition,if it's loose its the wrong one.