Silver bars: cast and minted bars, weights and purities

A silver bar is a block of refined silver of stated weight and fineness, stamped by the company that made it. In that respect it is exactly like a gold bar. In practice, silver behaves very differently once you start buying it: it is bulky, it costs more to make relative to its value, and the premium you pay over the metal price is a much larger share of the total. This guide covers the formats, the weights and the marks you will meet before you buy silver bars.

Two ways to make a silver bar

Cast bars

A cast bar is made by pouring molten silver into a mould. As it cools, the surface forms ripples, small shrink marks and soft, rounded edges, so no two bars look quite the same. The refiner’s stamp, the weight, the fineness and often a serial number are pressed into the top afterwards.

Casting involves few production steps, so it is the cheapest way to turn silver into a saleable bar. That is why the large sizes (100 oz, kilo and above) are nearly always cast, and why cast bars usually carry the lowest premium for a given weight.

Minted bars

A minted bar starts as a rolled strip of silver. Blanks are cut to an exact size and struck between dies under heavy pressure, which gives flat faces, sharp edges and a crisp design, sometimes with decoration on the reverse. Minted silver bars are often sold sealed in plastic or in a card.

The extra steps add cost, and in silver that cost is felt more because the metal itself is cheap per ounce. Minted bars are most common in small sizes, where buyers value a uniform shape that stacks neatly and is easy to check.

The weights you will meet

Silver is weighed in troy ounces, not the ordinary ounces used for food. One troy ounce is 31.1035 grams, about 10% heavier than an everyday ounce. A few dealers also sell fractional and gram sizes, but these carry very high premiums.

The large bars at the bottom of the table are the wholesale standard set by the London Bullion Market Association (LBMA). A good-delivery silver bar must weigh roughly between 750 and 1,100 troy ounces, have a minimum fineness of 999 and come from an accredited refiner. Private buyers rarely own one, but the accredited list is the reference that dealers use when they decide how readily to buy a small bar back.

Two sizes have their own guides: 1 oz silver bars and 10 oz silver bars.

What the purity stamp means

Fineness is expressed in parts per thousand of pure silver.

• 999 (“three nines”) means at least 99.9% silver. This is the standard for most investment bars and the LBMA minimum for good-delivery bars.
• 999.9 (“four nines”) means at least 99.99% silver. Some refiners strike their bars to this standard; it adds nothing meaningful for an investor, since you are paid on the silver content either way.
• .999 and older marks. Older bars often show the fineness as a decimal (.999 or .999+ FINE), and many also say “FINE SILVER”. These marks mean the same thing as 999.

Anything below 999 is not standard investment silver. Sterling silver, for example, is 925 and is sold as jewelry or tableware, not as bullion.

Why silver premiums are higher in proportion

The cost of refining, casting or striking, packaging, insuring and shipping a bar is roughly similar whether the bar is silver or gold. But an ounce of silver is worth far less than an ounce of gold, so those fixed costs become a much larger percentage of the price. A premium that looks small on a gold coin can look large on a silver bar of the same weight.

Three practical consequences follow:

1. Bigger bars are cheaper per ounce. The gap between a 1 oz bar and a 100 oz bar is usually wide.
2. The round trip costs more. The difference between a dealer’s selling and buy-back prices is often wider for silver than for gold, so short holding periods are expensive.
3. Tax can matter. In some countries silver bars attract sales tax or VAT while investment gold does not. Check the rules where you buy and where you store.

You can follow the metal price on our silver bullion prices page and compare it with what dealers charge.

Storage: weight and volume

Silver is far less dense than gold, and much less valuable per ounce, so the same sum of money in silver takes up dramatically more space. A single 100 oz bar weighs over 3 kg; a thousand ounces of silver weighs about 31 kg, roughly the weight of a large suitcase full of books.

This affects how you hold it:

• a home safe must be rated for the weight, and floors and shelves should be considered for large holdings;
• vault storage is usually charged on value, but some providers charge on weight or volume for silver;
• moving a large holding means real physical handling, and insurance cover should match the full value.

Bars stack more efficiently than coins, which is one reason buyers with larger amounts choose them. Keep bars dry and away from rubber, wool and some paper products, which contain sulfur and speed up tarnish. Tarnish does not reduce the silver content, but bright, untouched bars can resell more easily.

Buying silver bars sensibly

• Prefer well-known refiners whose bars dealers recognize at once.
• Compare the price per ounce of silver, not the price per bar.
• Ask for the buy-back price on the same day you buy.
• Decide on storage before you buy, not after.

Our step-by-step guide to buying silver bars covers dealers, payment and checks on delivery.

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