Manufacturing tolerances on the threaded portion of taps for producing ISO metric threads of tolerance classes 4H to 8H and 4G to 6G. Valid for short taps specified in ISO/R 529 as well as any other kind of ground thread taps with the same diameters and pitches.Cross References:BS 949:Part 1BS 949:Part 2BS 949:Part 3BS 949:Part 5BS 3643:Part 1BS 5346ISO 529ISO 2283ISO 2284ISO 5969