Definição

• Thickness Strip.  Coinage strip metal, rolled to the proper gauge or thickness waiting to be blanked. A different thickness strip is required for each denomination of coin as each may be a different thickness. Thickness strip must be made from an ingot of correct composition before being processed in a rolling mill, where it is rolled to a precise diameter to meet the specifications of a particular coin, a prescribed thickness.
  The United State Mint, prior to 1964, rolled and blanked all thickness strip at the Mint for all coins. Since the introduction of clad composition in 1964, the United States Mint receives clad strip in rolls from outside suppliers. These are blanked within the mint (with the exception of cent blanks which are blanked by the supplier). The thickness strip for both pre 1964 coins and current clad strip is as follows:
  United States Coins
  Denomination
  Face Value
  Diameter
  Thickness
  Standard (gross) weight
  Weight tolerance
  Fineness
  Fineness tolerance
  Pure gold or silver content
  Minimum legal weight of new coin
  Abrasion Tolerance
  Inches
  Millimeters
  Inches
  Millimeters
  Troy Ounces
  Grains
  Grains
  Thousandths
  Thousandths
  Grains
  Grains
  0.5% for 20-years wear. Grains
  Minimum current weight after 20 years wear. Grains.
  Annual abrasion within legal limit. Grains
  Actual coefficient of annual abrasion (from experiments). Grains
  Gold
  Double Eagle
  $20
  1.350
  0.0968
  1.07500
  516.0
  0.50
  900
  1
  464.4
  515.50
  2.58
  513.42
  0.1290
  0.0860
  Eagle
  $10
  1.060
  0.08
  0.05375
  258.0
  0.50
  900
  1
  232.2
  257.50
  1.29
  256.71
  0.0645
  0.0430
  Half Eagle
  $5
  0.848
  0.0582
  [Indian]
  0.26875
  129.0
  0.25
  900
  1
  116.1
  128.75
  0.645
  128.355
  0.0322
  0.0215
  Quarter Eagle
  $2.50
  0.700
  0.042
  0.134375
  64.5
  0.25
  900
  1
  58.05
  64.25
  0.322
  64.178
  0.0161
  0.0107
  Dollar
  $1.00
  0.585
  0.033
  0.053575
  25.8
  0.25
  900
  1
  23.22
  Silver
  Dollar
  $1.00
  1.500
  38.100
  0.114
  2.8956
  0.899375
  412.50
  60.00
  900
  6
  371.25
  411.00
  Half Dollar
  $0.50
  1.205
  30.607
  0.086
  2.1844
  0.400875
  192.90
  4.00
  900
  6
  173.61
  101.40
  Quarter Dollar
  $0.25
  0.955
  24.257
  0.067
  1.7018
  0.200937
  96.45
  3.00
  900
  6
  86.805
  94.95
  Dime
  $0.10
  0.705
  17.907
  0.053
  1.3462
  0.080735
  38.58
  1.50
  900
  6
  34.722
  37.08
  Minor
  Five Cent
  $0.05
  0.835
  21.209
  0.078
  1.9812
  0.16075
  77.16
  3
  Five cent, silver
  $0.05
  0.835
  21.209
  0.078
  1.9812
  0.16075
  77.16
  3
  One Cent, bronze
  $0.01
  0.750
  19.050
  0.062
  1.5748
  48
  2
  95 Cu, 5 Zn + Sn
  One cent, copper-zinc (1942, 1944-47)
  $0.01
  0.750
  19.050
  0.062
  1.5748
  0.1
  48
  2
  95 Cu, 5 Zn
  One cent, zinc coated steel (1943)
  $0.01
  0.750
  19.050
  0.062
  1.5748
  0.08646
  41.5
  3
  steel with.001-in zinc plating
  One Cent, zinc coated steel (1943)
  $0.01
  0.750
  19.050
  0.062
  1.5748
  0.08854
  42.5
  3.5
  steel with.001-in zinc plating
  A standard silver dollar contains 0.7734375 troy ounces of pure silver.
  All standard silver subsidiary coins contain 0.723375 troy ounces of pure silver per one-dollar face value.
  One cent coins of copper/zinc composition contained a trace of tin sufficient to be detected on analysis.
  Source: "Regulations for the Transaction of Business at the Mints, Assay Offices, and Bullion Depositories of the United States," Treasury Department, U.S. Mint. December 1, 1947.
  $ Liberty = 0.065 thick
   
  `                                   `

  excerpted with permission from

  An Encyclopedia of Coin and Medal Technology

  For Artists, Makers, Collectors and Curators

  COMPILED AND WRITTEN BY D. WAYNE JOHNSON

  Roger W. Burdette, Editor

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