Farm Collector

Weighing in on Egg Scales

My experience with egg scales started when I was a child on our farm in South Dakota. I had the responsibility of collecting, washing and weighing eggs. Today, the first question people ask when they see my egg scale collection is why eggs are weighed. People usually haven’t considered how the eggs they purchased were classified. As a boy, I weighed and cleaned eggs to increase the price of a dozen eggs by a few cents as I placed them in 30 dozen cases to be sold to grocery stores and egg processors. 

Grading of eggs by weight began about 1900 as a way of selecting the ideal size egg for hatching purposes. Early “egg graders” were preset to select eggs of a certain weight.  During World War I, the U.S. War Department bought eggs in large quantities and paid for them on the basis of size, which was determined by weight. Since poultry farmers were paid a premium for graded eggs, i.e., eggs that were sorted by size, World War I created an immediate market for “egg scales.” Farmers graded eggs to sell to retailers as a source of cash, thus perpetuating the need for egg scales. World War II created the greatest single demand for egg scales as the U.S. War Department bought eggs in huge quantities to feed the troops overseas. Most egg scales were invented and manufactured between 1920 and 1940.

A Specialty product

Acme egg grading scales were produced by Specialty Mfg. Co., St. Paul, Minn., founded by William Boss in 1900. Specialty’s first products included a grass catcher for a lawn mower, clothesline reel and garden hose reel followed by several other items, including the Acme egg grading scale. In 1922, Acme inventor N.E. Chapman filed for a patent for what he referred to as an egg grading device. The patent was granted in June 1924.

Still in operation today, Specialty manufactures numerous products for various industries. The company chairperson is Heidi Sandberg McKeown, great-granddaughter of the company’s founder.

Fins tell weight

Early Acme egg scales were of aluminum construction. Later models have tin bases that tended to rust over time. The scales work on the weight-lifting principle. Each scale has nine fins that are lifted to determine an egg’s weight. The weight of the egg lifts individual fins that rise until the precise weight of the egg is determined.

The egg cup on the 1924 patent for the Acme scale is generally oval like an egg and is parallel to the scale. However, the cup on some scales is positioned at right angles to the scale. Those models were probably produced after 1933. The egg cups are attached with aluminum rivets or with two slots cut in the cup and an aluminum strip holding the cup in place. The weight shown on the scale is the calculated weight per dozen, not the weight of one egg.

The Acme egg grading scale sold for $3 in 1928 ($38.64 today) and $4.49 in 1962, when production may have ended.

Geographic variations

Various geographic areas required specific weights per dozen. Twelve grading ranges have been identified for Acme scales. A Specialty Mfg. Co. advertising brochure showed geographic areas associated with specific Acme grading ranges. The most common grading ranges for Acme scales seem to be 19 through 30.

A “new, improved” version of the Acme scale with a flanged front guide for the fins was introduced at the Chicago World’s Fair in 1933-34. On that model, the numbers appear on the flange rather than on the fins. This scale also operated on a weight-lifting system. The fins are raised through slots on the flange on the left side of the scale. Each fin was attached to the scale with a small pin that went through a hole in the narrow end of the fin. Between each fin is a small brass washer to reduce friction. In the two versions of Acme scales, the back view demonstrates the difference in the size of the base of the scale. The flanged scale has the narrower base.

Accuracy could be affected by friction on the fins as they are raised through the slot. The guide’s light-weight aluminum fins and slots are easily bent, which also could affect accuracy.

Egg scales were manufactured in Australia, Canada, England, Germany and the U.S. Among the most popular scales produced in the U.S. were the Acme, Brower (Quincy, Ill.), Champion (Edmonds, Wash.), Jiffy-Way (Owatonna, Minn.), Mascot (Minneapolis), Oakes (Tipton, Ind.), Petaluma (Petaluma, Calif.), Reliable (Los Angeles) and Zenith (Cortland, N.Y.).

Most egg scales were made of sheet metal, though others were made of brass and iron. The manufacturer’s name was painted or inscribed on some egg scales. Others had paper labels that disappeared over time, making them more difficult to identify. Lesser-known egg scales such as the Egg-Xact, E-Z Egg Scale, Gilt-Edge, Hart Tru-Way, Kresky, Magic, Royal, Standard Long Beam, Universal, and White are difficult to find and more collectible. The Acme egg grading scale featured in this article was one of the earliest egg scales manufactured in large quantities. Made of aluminum, the Acme was not prone to rust and served its owner much longer than sheet metal egg scales.

Foreign connection?

Two foreign egg scales similar to the Acme have been seen by collectors. Little is known about the origins of either. The Canadian Dominion scale has seven fins. It shows the weight-per-dozen grading range and uses the weight-lifting principle. It is mounted on a flat, bone-shaped, cast-iron base painted green.

The second scale similar to the Acme is the Multiplo egg grader from Australia. The scale sold for $1.69 Australian in the 1949 Clarks’ catalog. It has the same weight-lifting principle as the Acme, with nine fins, but the grading shows the actual weight of one egg in 1/8-ounce increments, rather than weight per dozen.

As on the Acme, the flange at the end opposite the egg cup (on the later scale) is an improved design to provide a much more rigid frame than the earlier model, although it is shaped differently than the later model Acme. Multiplo also stayed with the cast aluminum base for its later model. FC

This article was adapted from the original text published in Equilibrium, the Quarterly Magazine of the International Society of Antique Scale Collectors, Issue 1, 2008. Visit the society online at

Bob Jibben began collecting analytic scales about 20 years ago. Today his collection includes egg scales, grain scales and weights. Contact him at (612) 925-1386; e-mail:

  • Published on Mar 31, 2011
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