About

Penny size is bullshit. Penny size applied to different nail types means a different length! Read this - [1]
Joist hanger names were called Tico nails [2].
- If double top plate - then 1.5" is not the limitation and 3" nails should be used.
- Sometimes 10D refers to diameter, as Tice 1.5" are called 10D - read comments at [3]
Building code defines a 10D nail as a .148 nail, 3" long [4]
1" is 2D [5]. Note that penny size came historically from cost of the nails in pennies. So the length is not proportial to D size. [6]. The only thing we know is that the larger the D number, the larger the nail.
10D is 3" long - [7]
Joist hanger nails do not seem to have D size attached to them - this one is 1.5" [8]
This 8D is 1.5" long [9]. Is that an error? Chart says 8D is 2.5".
3.5" common nail, galvanized. 16D [10]

Mitek Teco Nails + Gun