3′ 0″ diam., 9 oval spokes, vee inner rim, 3½″ apparent tread, 6″ tyre width.
Hub 10¼″ face dia., spreading to 14¼″ at the base rim, 1½″ out from the tyre.

Sources: 4MT measured direct and BR Derby works drawing.

Casting: 28.6 mm tread dia., 22.9 mm i/d, hub 1.1 mm out from the tyre.
Tyre widths for exact scale models at 1:32, 6″ = 4.8 mm.

Casting prices and stock . BR loco sets, price list

Scan of a casting in a set for a BR 4-6-0 4MT . 2-6-4T 4MT