B Grade pins have very small amounts of extra metal on the edges of the pin in certain areas such as the very tip of the pineapple. It is barely noticable.
C grade pins have slightly unpolished metal. 
Please refer to seconds grading info below for more details.

* Size: approx 17mm x 22mm (0.7" x 0.85")
* Copper plating
* Hard enamel
* Butterfly fastener/backing