Tire Tread Depth

I just bought some Cooper AT3 Discoverer’s in 265/70R-16. I had a long discussion with the owner of the shop as these are not the 10 ply tires I thought I ordered, but he said I should have better protection from flats on logging roads than the stock tires I just took off, and it should stay that way for at least 50% of tread depth wear. He also said I probably wouldn’t like the way 10 plies would ride.

So, I’m trying to figure out what the dread depth is. I measured about 11/32 if I read it correctly. The Cooper site says tread depth is 16.5. My question is What is 16.5? Must be something smaller than mm, but the Cooper site does not say what 16.5 is.

 

By the way, I tried searching to see what a tread depth of 16.5 from the Cooper site meant, but came up with zeros.

A couple of photos for those of us that need photos.

 

5 days and 155 views, and no one understands what 16.5 tread depth means?

Look at the screen shot from the Cooper site below and the column I have circled in red. I’m thinking tread depth for my AT/3's is 11/32, but I can’t convert that to 16.5 anything. Nothing at all on the Cooper site says what that column’s measurement is. Doesn’t anyone know?

 

Ok. Never mind. I got my answer in about two minutes in a gun forum. How is it that no one in the tire section of this forum does not know the answer to my question? I even gave this forum 5 days to try an answer my question, yet it took only 2 minutes to get my question answered on a forum that has nothing to do with automobiles.

 

What was the answer ? I have same tyres and love them they move water like no other tyres I've had..