The Commonwealth Period comes near the end of the English hammered period. That makes Commonwealth hammered coins doubly interesting as they reached their peak for quality at a time when milling was seriously seen as a competitive technology. Using the hammer had two major advantages - high speed and low cost - both factors dictated that the mint would find it difficult to implement the mill. There was one downside cost which was due to the number of dies which had to be made to sustain production. Typically a halfcrown size die might last on average for 8,000 strikings. With care more with abuse less. On the other hand low quality hammered coins from the mint allowed forgers to make counterfeit coins, mainly the halfcrown. The forgers piece was usually under weight and very badly double struck to the point where it made reading details very difficult. The response of the mint was to include subtle changes to the design of both the reverse and the obverse so that a genuine piece was obvious if the observer knew the changes for each year. The forger never matched these changes for his was made using an early Commonwealth piece as his master copy and his changes were often limited to the date.
Civil War hoards reveal that only the halfcrown, shilling and sixpence were in daily use in the street with merchants. The gold unite, double crown, gold crown and silver crown have so far not been found hidden away. It appears their production was not for common use but maybe instead for trade which lead to the weight of gold or silver in these coins needing to be carefully controlled to the correct weights and metal purity.Their overall quality is much superior to the low denomination silver in everyday use.