Vintage 1957 Sun Hemmi No. 257 Chemical Engineering Slide Rule Japan Bamboo Good For Sale

VINTAGE 1957 SUN HEMMI NO. 257 CHEMICAL ENGINEERING SLIDE RULE – MADE IN JAPAN

Wonderful vintage Sun Hemmi No. 257 duplex slide rule, manufactured in Japan and specifically designed for chemists and chemical engineers.

The rule is marked:

SUN HEMMI JAPAN – HI – NO. 257

The “HI” date code corresponds to September 1957, making this a genuine 1950s scientific/engineering instrument.

International Slide Rule Museum

This is not simply a standard classroom slide rule. The Hemmi No. 257 was designed especially for chemical-engineering calculations and incorporates numerous specialized scales. According to the original Hemmi instructions, its functions include ordinary multiplication and division, squares and square roots, logarithms and exponents, atomic and molecular weights, temperature conversions, pressure conversions, concentration calculations, saturated steam/vapor calculations, and other chemical-engineering functions.

International Slide Rule Museum

DETAILS:

Manufacturer: Sun Hemmi

Model: No. 257

Made in Japan

Date code: HI – September 1957

Approximately 12.6 inches / 320 mm overall

Bamboo construction with white scale surfaces

Duplex design with scales on both sides

Original metal-framed magnifying cursor/indicator

Specialized chemical engineering scales

Temperature scales for °F, °C and °K

Pressure conversion scales

Logarithmic and exponential scales

Numerous additional scientific calculation scales

The International Slide Rule Museum identifies the No. 257 as a bamboo chemical-engineering slide rule measuring approximately 320 × 44.7 × 7 mm.

International Slide Rule Museum

CONDITION:

Pre-owned vintage condition with age-related wear, discoloration, marks and surface wear as shown in the photographs. The center slide and cursor both move. Please examine all photographs carefully, as they are an important part of the condition description.

No case or instruction manual is included unless shown in the photographs.

An interesting collectible for a chemical engineer, chemist, scientist, engineering-history collector, slide-rule collector, or vintage scientific-instrument enthusiast.