Tyre specs

[the silver surfer]

I just wanted to find out what opinions are out there with regards to specific tyre specs. Now if you do, or don't know, don't research it, I just want to know what your understanding is of "PLY". Again, not looking for a wiki explanation and there is method to my madness!!!! Sometimes All will be revealed after a few responses. I don't care if it's right or wrong, I just want your thought.
Gracias

[NiftyNev]

Ply, as far as I know, referes to the layers (which could be a number of materials) that hold the tyre tread and sidewall area together. Without that, I suppose the tyre would not retain it's shape and probably just be a balloon when inflated.

Nev.

[the silver surfer]

That was my understanding too, more or less. So imagine how excited I got when I found a tyre that claimed to be 10 ply, YES, TEN PLY!!! I thought that if my old 6 ply GT Radials would last 6 years out on sharp stoney tracks then 10 ply would last forever without puncture. But I was still a little sceptical, so I messaged and messaged and messaged some more the manufacturer and resellers of this tyre, trying to find out what these 10 ply's were. My GT's we 2 Nylon, 2 Steel & 2 Polyester.
Finally I get a response from the CEO of the manufacturer actually informing me the the structure was in fact 6 ply, exactly the same as the GT's. So why say 10 ply I asked, it's the format for 'load range' apparently. Well, I calmly told him that was bollox and was misleading to people who may well purchase them online based on them having 10 actual layers, devious bar stewards! The tyre make? Interstate All Terrain GT in size 265/75/16. Looks the business, but NOT 10 ply as advertised.

[markp2]

My understanding from agricultural tyres is:
In the 'old days' the ply was the number of actual layers of fabric in the carcass of the tyre. In more recent times it has changed to 6 or 10 ply RATING (eg 6PR on the sidewall).
With the advent of steel and Kevlar layers in the tyre, a 10PR tyre will probably only have 6 actual layers but some these will be stronger than a single fabric layer which makes it at least as strong as an old 10 layer tyre.
Mark.