What are part-worn tyres?

Used tyres with less tread left than that of a new tyre are considered “part worn” and are sold as “second-hand,” “part worn,” or “budget” tyres.

If you’re looking to save money, consider purchasing part worn tyres. It’s a safe bet to purchase new tyres if you know their history (maybe a buddy has some track day rubber they no longer require), but it’s incredibly improbable that you’ll know what type of history comes with a partially worn tyre.

Original Source: https://www.quora.com/What-are-part-worn-tyres/answer/Road-Runner-Tyres