This part of ISO 3739 specifies the main requirements of the metric series of pneumatic tyres primarily intended for industrial vehicles, including designations, dimensions and markings. The tyres are based on the following parameters: - speeds not exceeding 50 km/h; - use on 5° tapered or flat base rims. The conversion of code-designated industrial tyres into metric-designated tyres is outside the scope of this part of ISO 3739.