Found at Stein Castlecary Works, Castlecary.
From invoices recovered at the Stein, Manuel Works I believe these metal-encased bricks may be ‘related’ to
Contex MAG CSD – R Metal cased 230mm x 178mm x 76/70mm – £336.80 per tonne
Contex Mag CSD/W metal cased 300mm x 175mm x 90mm O/ALL pos FR2/1 Steel sheeted (22 gauge) with Detrick recess suspended ends – £315.90 per tonne
Example below measures approx – 230mm x 120mm x 70mm
Below – and this example measures approx 375mm x 125mm x 70mm
Below – 1968 – John G Stein & Co Ltd. A film held by the National Library of Scotland – These film stills show you these steel-clad bricks being made at the Stein Works – the steel sheath oxidises in the heat and welds the bricks together forming a self-supporting arch.
Below – The 2 photos below were taken within the Manuel Works c.1980 and appear to show the steel-clad bricks being made.
Harley Marshall, ex Export Manager at the Stein Manuel Works states the bricks were manufactured as chrome magnesite or magnesite chrome bricks. He remembers them being called 18/8’s or 25/20’s and recalls this referred to the nickel/chrome or chrome/nickel content of the steel plating. He states the basic bricks were made at the Manuel Works and transported to the Stein Castlecary Works to be clad in the steel jackets.
They were hung back to back on special hooks or tabs from perhaps a furnace roof. In the heat, they fused together forming a strong self-supporting roof.
It is believed the MAG CSD stands for Magnesite Chrome Steel- clad Dense
These bricks were rebranded to the Contex name on the merger with General Refractories
Below – Further information on steel-clad bricks taken from a John G Stein publication of unknown date.