Fire King Mug Bottoms
The photos and descriptions below are a guide to help gauge the dates of production of Fire-King mugs.  The dates are all approximate.  Much information about the dating of Anchor Hocking’s markings can be found in Anchor Hocking’s Fire-King Glassware by Garry & Dale Kilgo and Jerry and Gail Wilkins, published in 1997.  As a general rule, the less embossing on the bottom of a mug, the older it is – however one common exception is that “Fire-King Glass” is older than “Fire-King Ware” (one alphabetic character difference!)  Also, though not specified in any of the descriptions below, the mugs made after about 1950 will usually have a 2-digit mold number embossed on bottom as well.  These mold numbers carry virtually no collector value or meaning

Fire-King Oven Glass  Early 1940's	Oven Fire King              Mid 1940's	Oven Fire King Ware Latter - 1940's
Anchor  Hocking  Fire-King Ware  Made in USA    1960's	Anchor  Hocking Fire-King  Made in USA   Into the 1970's	Anchor  Hocking Fire-King  Oven-Proof Made in USA   Throughout the 1970's
Anchor Hocking Fire-King Oven Proof  Made in U.S.A. Late 1970's - 1981	Anchor Hocking 910 Fire-King Oven Proof  Made in U.S.A. Institutional	Anchor Hocking Oven Proof  Made in U.S.A. Placesetters Collection 1970's
	Mold Number 1960's
		This is the bottom of a 1960s era D-Handle mug showing only a mold number.  I have seen this pattern mug on Ebay, and that mug’s standard bottom stamping dated it to the 1960s.  This is also the same bottom stamp style as the B.C. series “Grog” high relief molded mug.  Genuine unmarked Fire-King mugs are a bit of a rarity (except the Grog mug where this type marking is standard).