Identification guide
Pyrex date codes
With Pyrex date codes, capacity wording and the PYREX trademark are separate. Copyright, patent and mould numbers serve different purposes.
Model numbers versus production dates
A 401 identifies a mixing-bowl model and a 404 a different size in the nested series. Capacity wording and the PYREX trademark are separate. A painted pattern or a documented catalogue introduction can narrow the period when a model and decoration were sold.
What to record
| Mark | Role |
|---|---|
| PYREX word mark | Brand and trademark form |
| 401 or 404 | Model and size identification |
| Capacity wording | Volume |
| Pattern and catalogue appearance | Production-period evidence |
What to check next
Compare the trademark form, model number, capacity and decoration with a catalogue entry for that product. Copyright, patent and mould numbers serve different purposes. Read them as labelled rather than splitting an arbitrary three-digit model into a year.
Related marks
7 marks
Fire-KingMark wording
Undated
Unattributed marks
glass
………………………. Anchor-Hocking Corporation (1937-to date). This has been an extremely popular line of glassware since introduced in the 1940s. glassware has been made in semi-opaque or “translucent” colors, as well as fired-on colors over transparent or white milk . is made of a heat-resistant type of , and many patterns and styles of bowls, cake pans, and other items for oven use have been made, competing with Pyrex-brand cookware made by Corning Works . Large numbers of drinking mugs and cups have been made with the brand name logo on the bottom, and these are avidly collected today, especially by the so-called “baby boomers” growing up during the 1940s, 1950s and 1960s, when so many of these items were in popular use in most American homes. Many of the mugs and bowls have surface-applied color decoration, which sometimes begins to wear off, thus washing them in an automatic dishwasher is strongly discouraged. Vintage ware has great nostalgic value, and can be seen frequently for sale at antique malls, flea markets and garage sales. Please see “Anchor with an H superimposed” mark on this page: Anchor Hocking Corporation .
GlasbakeMark wording
Undated
Unattributed marks
impressed · glass
………………………….. McKee Company , Jeannette, Pennsylvania. “ ” is a brand name embossed on the bottom of much glassware for household use. This was a popular name introduced and used by McKee for their high-quality, heat-resistant ovenware, serving bowls, and other kitchen ware. The line was introduced in 1917, and competed with Pyrex (made by Corning Works) and Fire-King (Anchor Hocking Corporation). The formula was changed (after a lawsuit was filed by Corning) and re-introduced in 1919. The brand was used more or less continuously throughout the succeeding years, under Thatcher ownership (1951-1961), and later by Jeannette Company until 1979. See McKee Company page for a little more general information on this operation.
K (on the base of modern-era clear laboratory, pharmaceutical & scientific glassware including serum bottles, beakers, etc)Mark wording
Undated
Unattributed marks
glass
……………… Kimble Company, later Kimble-Kontes, later, Kimble Chase Inc. (part of the Gerresheimer Group), Vineland, New Jersey. Kimble-Chase was later acquired by DWK Life Sciences in 2016. Kimble produces borosilicate under the trade name KIMAX (similar to PYREX). See “K in a hexagon”, below. In some cases the “K” may be rather small and unobtrusive on the base of bottles, and accompanied by a group of raised dots. (The dots, in this case, are numeric mold codes that can be scanned or “read” by high speed electronic inspecting machines – to capture information that identifies the exact mold in which a particular bottle was made).
PYREXMark wording
Undated
Unattributed marks
glass
…………………….brand name used by Corning Works on a wide variety of glassware including bakeware, dinnerware, laboratory, medicinal and chemical bottles, and industrial including electrical insulators. For more info, please see webpage on Corning Company/Works, Corning, New York (1875-to date).