Found Firth of Clyde, Glasgow.
Unidentified maker.
Find location would suggest Scottish origins but …
I believe it says IFB but there is a possibility it says JFB but I don’t think so!
Possibly the Inverkeithing Fireclay Brickworks – click me
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Below – Interestingly this IFB stamped brick was found in Wollongong, Australia. Are these bricks from the same brickworks? If they are the same brick were they manufactured in Scotland or Australia.

Below – These firebricks were manufactured by the Inverell Fire Brick, Australia.
Below – Found by Craig Powell in WA, Australia.

Below – Found by Leslie White in Australia.

Jean Bear, USA states “Here, the IFB was made by Corundite Refractories Company in Zoar, Ohio from 1930 until 1965. Perhaps they were made in other places? Oral history tells us that “IFB” stood for “International Fire Brick” but I don’t have proof”