Dare I say that Barbara Todaro "nailed" this one? 

16 penny nail also referred to as 16D (D equates to penny!) and it's 3.5" in length....that's a commonly purchase nail.... most used.... a full set of house plans will usually recommend the size of nail for the nail gun...

A big one .... too big for hanging pictures.

Coated or uncoated is the next question?

When I first heard this, I remember what does money have to do with a nail and then realized...oh, you get so many for a penny....LOL  True story

Anna Hatridge - you know the new construction queen... Barbara Todaro ...

I'll go with Barbara Todaro And Annette Lawrence , Palm Harbor, FL 727-420-4041 answer.

I think Bob Crane gave you a good answer.

Anna Hatridge Indicates the length of the nail.

Standard nails that are around 3 1/2 inches I think. Interesting terminology that's used to identify different sizes of nails

Relates to the size of the nail.  

About medium size, probably about 3-4 inches long.

Usually 3.5 inches long, used for framing, requiring a real hammer and adequate hand-eye coordination to drive that fastener home.

Four stokes should to it. A non-pro can be heard whacking at it 25 times.

Haven't heard that term used in many years.

I think they are the largest nails I have in my garage.

Barbara Todaro nailed this one!

LOL - I don't keep any of those on hand since we seldom use that size

standard nails use to build homes

I never knew - but now I do thanks to Barbara Todaro 

No idea.

I like the response by Barbara Todaro. 

What Barbara Todaro said and LOL @ Kathleen Daniels' answer! 

nail length= 16 stacked pennies...

I think Barbara Todaro answered it better than I could have!

It's a big nail. I once got up close and personal with one when it rammed it's way through the bottom of my shoe and well into my foot. 

Barbara Todaro knows her nails!

Well Barbara Todaro nailed it again!

Barbara said it well

Barbara would know this one.

Used in framing a house with a head on it. This is a big substantial nail.

Many good answers here.

Barbaea Todaro nailed it. I can remember the days before nail guns when you drove a nail with a hammer!

Sounds like a nail that costs (or used to cost) 16 cents, but I know that's not it.

Barbara Todaro has it!

Most often i would hear them called framing nails. Our last local hardware shop is now gone, where the owners would go over penny nails and have everything and anything you need, not like these mega stores. 

Not a clue... will need to read the answers you get.

Not sure.  Parked and reading!