Allegheny Plastics Inc., Illinois Coil Spring Company Slide Rule

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Country of manufacture: USA,            Date of manufacture: >= 1967
Diameter: 10.8 cm,          Weight: 19.6 gms.
Materials: Transparent plastic disks over laminated plastic/paper disk
Cursor: plastic, duplex-type; lines = single hairline, front & back
Scales: 10, specialized
Front: Wire Diameter [ Mean Diameter, Active Coils, G ] Lbs per inch Deflection
Back: Mean Diameter [ Wire Diameter, Ratio D/d, Load ] Stress
Gauge Marks: [      ]
Condition: C3-C4 (Very minimal to minimal signs of use)
Came with: Original shipping sleeve imprinted with instructions for use.

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