Hamilton pocket watch serial number dating
Locate the movement number, which consists of three digits sometimes combined with a single letter, and the multi-digit serial number.For example, movement number "986," and serial number 2100001, will identify a 1922-1926 Hamilton wrist watch.Rob Wagner is a journalist with over 35 years experience reporting and editing for newspapers and magazines.His experience ranges from legal affairs reporting to covering the Middle East.A light, even patina across the dial and unblemished, or slightly blemished numbers, markings and hands indicate the watch is likely original and classified in good condition.Pristine color and perfect markings on an 80-year-old Hamilton may indicate a restoration.Movement size: 16, 1.700 inches, 43.18 mm diameter Approximate watch size (depends on case): 2 inch (5cm) diameter, weight 90g Jewels (gemstone bearings): 21, friction set, all upper jewel settings are gold Rate: 2.5Hz, 5 beats per second, 18000 bph (beats per hour) The watch runs about 52 hours when fully wound Balance wheel: Aurium, a monometallic beryllium-silver-nickel alloy, Aurium is a Hamilton marketing term (trademarked in April 1940 by Hamilton), the exact composition of the alloy was kept secret. Hair spring material: Elinvar-Extra Adjustement: temperature, isochronism and 6 positions Position adjustment refers to the mechanical design of the balance wheel and the hairspring.The little weights on the balance wheel are an important part of that adjustment.
It's the stuff you find on old light switches or old electrical sockets. It does not easily burn and is very resistant to chemicals.
Scan the crystal for scratches and cracks with the magnifying glass or loupe. Sapphire glass indicates an overhaul, since sapphire crystals were not available until the 1960s and 1970s. A signed crown on a prewar Hamilton indicates it’s not original.
Hamilton did not sign its crowns with an “H” until the 1950s.
Classification of the Hamilton in poor, fair, good or excellent condition is sometimes done by assigning a percentage.
For example, an unblemished well-running vintage Hamilton should be classified 90 percent or above to be in mint condition.