3′ 7″ diam., boxpok welded plate.
Hub level with the tyre.

Source: Winston Churchill measured direct at York, August 1995.

Casting: 34.1 tread dia., 28.6 i/d. Hub level with the tyre.

Casting prices and stock . SR loco sets, price list

Scans of a casting in a set for SR 4-6-2 Bullied Pacifics