Concise ruler circular slide rule 28N advertising Kennametal Mining Tools Made In Japan.

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I"Slide rule No. 27N" English Ver.

Most popular circular slide rule, calculations other than addition and subtraction... Basic slide rule that allows easy calculations such as multiplication, division, square and cube, so in all fields It is used.

Types of calculation: General multiplication/division, proportional (exponential percentage), square, and cubic calculations.

Back side: Describe the unit conversion of length, area, volume, mass, temperature, pressure, speed, etc.

Scale: D・C, CI, A, K (surface)