Engineering drawing drawing on A3 may be enlarged to A2 or reduced to A4. The U.S. customary "A-size" corresponds to "letter" size, and "B-size" corresponds to "ledger" or "tabloid" size. There were also once British paper sizes, which went by names rather than alphanumeric designations. American Society of Mechanical Engineers (ASME) ANSI/ASME Y14.1, Y14.2, Y14.3, and Y14.5 are commonly referenced standards in the U.S. Technical lettering is the process of forming letters, numerals, and other characters in technical drawing. It is used to describe, or provide detailed specifications for an object. With the goals of legibility and uniformity, styles are standardized and
Ledger Formation Ledger Formation The Ledger Formation or Ledger Dolomite is a geologic formation in Pennsylvania, United States. The Ledger is described as light-gray, locally mottled, massive, pure, coarsely crystalline dolomite. It may be siliceous in the middle part. Named from exposures at Ledger, Pennsylvania, formerly 3 miles northeast of Kinzers, Lancaster County, Pennsylvania. At Valley Forge National Historical Park, the visitor center parking lot is built within an old quarry of the Ledger, and the former quarry walls are exposed. The rocks contain stromatolites. In the nearby Port Kennedy Quarry, the Triassic Stockton Formation unconformably overlies the folded Ledger. The Ledger