Number1gun,
Industrial forms of precious metals are just that, intended for industrial use. You might get someone to accept it in trade after an assay and weighing, but that takes time, knowledge, and money to accomplish correctly, and decreases the liquidity of the item. The reason that assayed bars, officially minted coins, or commercially minted rounds are more accepted is because of their known quantity and quality, thus providing easily traded real money when the paper Federal Reserve Notes that we euphemistically call money become increasingly worthless.
As to the utility of PM's during a SHTF situation, the reason that one has them is to facilitate trade when barter is impractical. That is the whole reason that humans came up with the concept of money, in order to facilitate trade. Having a store of pre 1965 silver dimes, quarters, halves, and dollars will be the best form for everyday trade, with gold being more for large purchases and wealth preservation. This is not to say that one should not have other supplies mentioned in other posts such as food, ammunition etc. available for use and trade via barter, but unless you and the person with whom you're trading need what the other has for trade, you can't make a deal. That's where PM's shine-no pun intended, by being something that both parties recognize as having value, and that can be also recognized by other parties as having value to facilitate future trades.
In the current day the banks have degraded the concept of money to be debt and credit piled on more debt and credit, and easily debased and manipulated to the detriment of the public. Commodity money in the form of gold and silver are the real deal, and will take the place of the paper paradigm in the very near future. The last days of the paper system are upon us, and having metals will be essential to preserving purchasing power. 6000 years of history is very hard to ignore, and one does so at his peril.