San Francisco - 5 oz Class 1959 Round Dated Hallmark
1959 marks the only year that the San Francisco Mint produced dated 5 oz class silver ingots. The round dated hallmark uses U.S. Mint San Francisco instead of Mint Of The United States At San Francisco as we have seen on all Type I and Type II oval hallmarks to date.
Most of the 1959 round dated hallmark silver ingots that I have seen are from Lot 39, a direct lot carryover from Type II oval hallmark silver ingots. Almost as many can be found with no lot number and to date, I have found one with a Lot 40 on the leading edge facing. It is also common to see the hallmark applied to either side of the casting as shown above.
Very few 1959 silver ingots include the weight, the two below are among those. The second ingot is the only example of the 1959 round dated hallmark on both sides of the casting that I am aware of.
The example below represents the only 1959 US Mint San Francisco silver ingot I have seen to date from Lot 40. Note that the weight number font, ozs font and the lot font all differ from other 1959 round dated hallmark silver ingots.