Perrygraf Enamel Coating Calculator Slide Rule for Armco
- This blue, tan, and white cardboard rule consists of an envelope held together by six metal rivets and a paper slide. The rule calculates the weight of an enamel coating, given the area of a metal sample; the surface area of metal, given its thickness and weight; and the weight of enamel per square foot of surface coated, given the weight of enamel used, the thickness of the metal sample, and the weight of the metal.
- Perrygraf Corporation of Maywood, Ill., made this instrument (copyrighted in 1941) for the American Rolling Mill Company of Middletown, Ohio. ARMCO produced and enameled coils of sheet steel at plants in Middletown and Ashland, Ky. Since 1999, the company has been part of AK Steel. For more on Perrygraf, see 1979.3074.03.
- Reference: "American Rolling Mill Company," Ohio History Central: An Online Encyclopedia of Ohio History, July 1, 2005, http://www.ohiohistorycentral.org/entry.php?rec=840.
- Currently not on view
- Data Source
- National Museum of American History
- Perry Graf Corporation
- date made
- Credit Line
- Transfer from Smithsonian Institution Libraries
- Physical Description
- metal (part material)
- paper (overall material)
- overall: .2 cm x 22 cm x 7.6 cm; 3/32 in x 8 21/32 in x 3 in
- Object Name
- calculating rule
- slide rule