100 oz OPM Metals Silver Bar

The 100 oz OPM Metals Silver Bar

OPM Metals bars come from Ohio Precious Metals, a refinery founded in 1974 in southeastern Ohio and one of the few private refineries that operated solely within the United States. Following an expansion in 2003 it became the largest good delivery refinery in the US. The brand no longer exists: in July 2015 OPM merged with NTR Metals and rebranded as Elemetal Mint, so OPM-stamped bars are a discontinued product found on the secondary market rather than fresh from the refinery. That gives them minor collector interest beyond their silver content, similar to other discontinued American refinery brands.

At 100 troy oz, this is the heavyweight of retail silver bars, roughly 3.11 kg of metal in a single rectangular slab. The weight class exists for one reason: cost efficiency. Premiums on 100 oz silver bars typically compress to 2-4% over spot per ounce, the lowest of any standard retail silver bar size, because the fixed costs of manufacturing, assaying, and packaging are spread across a hundred ounces. By comparison, 1 oz bars often run 8-15% over spot and 10 oz bars 4-8%.

The trade-off is divisibility and the buyer pool. A bar is indivisible; selling means finding one buyer for the full amount, where 100 individual coins can be parcelled out over time. The 100 oz format is also a North American convention. European and Asian silver markets prefer metric weights like the kilo bar, so this size trades most fluidly with US and Canadian dealers. For accumulators building positions of several hundred ounces, the premium savings are significant; for buyers who expect to sell incrementally, smaller silver bars offer more flexibility.

100 oz Silver Bar Tax Treatment by Country

Privately minted silver bars get none of the legal tender concessions that some silver coins enjoy, and silver does not qualify for the investment gold exemptions in the UK and EU. At a 100 oz outlay, the tax differences between countries are material.

• US: The primary market for this format. No federal sales tax; roughly 35 states exempt bullion, around 10 tax it, and several apply threshold-based exemptions (for example New York and Massachusetts exempt transactions over $1,000, which a 100 oz bar comfortably clears). Long-term gains are taxed at the IRS collectibles rate of up to 28%. IRA eligibility for silver requires at least 99.9% purity under IRS Section 408(m); OPM sits among the refiners whose bars qualify when that fineness standard is met.
• UK: 20% VAT on purchase, and as a non-legal-tender bar it is also liable to Capital Gains Tax on sale. This double exposure makes large silver bars the least tax-efficient silver form for UK buyers.
• EU: Full standard VAT at national rates, from 17% to 27%. Margin schemes in Germany and the Netherlands cover pre-owned silver, which can apply to secondary-market OPM bars sold through participating dealers.
• Canada: GST/HST exempt when the bar is refined to at least 99.9% purity. The exemption is federal, with no provincial variation.
• Australia, New Zealand, Singapore: All exempt investment-grade silver from GST at a 99.9% purity threshold. Hong Kong has no sales tax or capital gains tax at all.

Ohio Precious Metals, From Garage to Elemetal

OPM's origin story is unusual for a major refinery. The company was founded in 1974 by precious metals enthusiasts who started by reclaiming metals stripped from telephone equipment, operating out of a garage in southeastern Ohio. From that scrap-recovery beginning it grew into a full refining operation, and after its 2003 expansion it ranked as the largest good delivery refinery in the United States.

Beyond generic bars, OPM produced branded products including a Chinese zodiac Lunar series of silver bars from roughly 2012 to 2015, covering the Year of the Dragon through the Year of the Goat. The company's independent history ended in July 2015, when a merger with NTR Metals created Elemetal Mint, at the time the largest private mint operating in the United States. Products carrying the original OPM stamp date from before that transition.

The Elemetal group's later history was troubled. NTR Metals entered a guilty plea in 2018 for handling illegally sourced gold, though OPM's silver refining operations were separate from that affair, and the Elemetal brand itself has since been restructured. None of this affects the metal in an OPM bar, but it explains why the brand disappeared and why these bars now occupy the same secondary-market niche as other defunct American refinery names. For stackers the practical takeaway is simple: OPM bars trade on their silver weight, with a modest discontinued-brand following on top.

OPM vs RCM, Asahi, and the Legacy Brands

The 100 oz silver bar market splits into three tiers: current LBMA-accredited production, discontinued legacy brands, and generics. The Royal Canadian Mint bar is the benchmark current product, struck in .9999 fine silver (a step above the .999 standard), serialised, and LBMA Good Delivery listed. Asahi Refining, which acquired Johnson Matthey's precious metals business in 2015, is the other major in-production name in North America.

On the legacy side, Johnson Matthey bars from the 1980s and discontinued Engelhard bars both trade at collector premiums driven by brand nostalgia and scarcity. OPM occupies a humbler spot in the same category: discontinued since the 2015 Elemetal rebrand, with minor collector interest but nothing like the Engelhard following. In practice OPM bars price closer to the generic tier, alongside names like Sunshine Minting and Republic Metals.

That positioning cuts both ways. Buying, an OPM bar should cost less per ounce than an RCM or Asahi bar, and the premium compression of the 100 oz format already puts it near the cheapest possible route into physical silver. Selling, brand matters: LBMA-accredited refiner bars command tighter buyback spreads, and most dealers will weigh, measure, or assay a secondary-market 100 oz bar before purchasing, an extra step compared with coins of known specification. Buyers who want maximum resale assurance at this weight pay up for the 100 oz RCM silver bar; buyers optimising pure cost per ounce will find OPM and other secondary-market American bars hard to beat.