The ISO 286 system uses an alphanumeric code to define a (e.g., H7 or g6 ).
and "h" (shaft) denote the zero line, where the lower (for holes) or upper (for shafts) limit deviation is zero. iso 286 pdf
ISO 286-1:2010(en), Geometrical product specifications (GPS) The ISO 286 system uses an alphanumeric code to define a (e
The standard is divided into two primary parts, which are often sought together in technical documentation or as an ISO 286 PDF for engineering reference: iso 286 pdf