Buying second-hand (part worn) tyres Second-hand or part-worn tyres are tyres which have been used on another vehicle. If you are thinking about buying a part worn tyre, you must ensure the tyre is safe and meets the minimum legal requirements. You should also think about whether or not you’re getting real value for money. The following are some important points to look out for before buying a part-worn tyre: 1. Check for an E-Mark on the tyre (Figure 2). Your tyres will need to carry an E-mark for the NCT. 2. Check that there is a minimum tread depth of 1.6mm on the tyre. Anything less is illegal for use on a public road. A tyre’s tread depth can be measured by using the handy pop-out tyre tread depth gauge attached to this leaflet (Figure 5). Always measure in the middle of the tyre surface, and not at the edges. 3. Tyres also have a ‘tread wear indicator’ block set into them at a depth of 1.6mm. You should check this block to ensure that this indicator is not at the same level as or lower than the tyre tread.