This International Standard specifies the requirements and/or measures to eliminate the hazards or reduce the risks in the following groups of turning machines and turning centres, which are designed primarily to shape metal by cutting.. Group 1: Manually controlled turning machines without numerical control.. Group 2: Manually controlled turning machines with limited numerically controlled capability.. Group 3: Numerically controlled turning machines and turning centres.. Group 4: Single- or multi-spindle automatic turning machines.NOTE 1 For detailed information on the machine groups, see the definitions in 3.4 and mandatory and optional modes of operatio