Once again the purported Apple iPhone 6S rear plate has appeared online, this time undergoing a proper bend test.

The apparent rear plate of the iPhone 6S, which is in the hands of YouTubers Unbox Therapy, has undergone more tests than their first video.

The plan was to find out if Apple has used new materials for a phone that won't suffer the bendgate issue of previous models.

So what got revealed?

The iPhone 6 uses 6063 aluminium which is not the strongest type with certain other metals in the mix. The newer model has a much thicker annodisation layer – they even had trouble sanding this off to measure the metal type.

The results for the iPhone 6S rear showed more zinc content meaning it is the 7000 series aluminium being used for the iPhone 6S. This is supposed to be stronger, and more expensive – up to five times more expensive.

In the bend test the rear plate of the iPhone 6, made with 6063 aluminium, began to bend at about 30lb of weight and by 35lb it was totally bent.

The purported iPhone 6S rear plate, with 7000 series aluminium, made it to 80lb of force without bend – the iPhone 6 complete phone, not just rear case, bent at 70lb.

So it looks like we can hope for a far stronger iPhone 6S to appear at its expected launch late this year. How much this will push the price up by isn't yet clear.

READ: iPhone 6S and iPhone 6S Plus release date, rumours, and everything you need to know