On HSN theya re offering the 2005 UNC sets that are graded SP (Satin Proof) 69. They say that it follows the Sheldon system. Since the planchets are not polished and the dies are just bead blasted, how can these conis be considered proof? The set that I received (and returned) had a significant number of dings on the Sacagawea and the Kennedy.
Here is what PCGS says a proof coin is: Proof A coin usually struck from a specially prepared coin die on a specially prepared planchet. Proofs are usually given more than one blow from the dies and are usually struck with presses operating at slower speeds and higher striking pressure. Because of this extra care, Proofs usually exhibit much sharper detail than regular, or business, strikes. PCGS recognizes Proofs (PR) as those struck in 1817 and later. Those coins struck prior to 1817 are recognized as Specimen strikes (SP). Just because they are "proofs" don't keep them from getting "dings" etc.
The question really is - graded by whom ? Regardless of who graded them - they are definitely not Proof coins.
Mint set coins would NOT be called proofs. I think you will find that the SP designation (I'm assuming this SP is on the label of a grading service slab.) means Specimen, not Satin Proof. They have used that SP designation for Specimen coins before.
