Part 20
| 20.mm1 Flanged and grooved wheel, solid brass, no recess | 20.mm.',400,287,'white')) As above, rough cast brass, recessed both faces (36g) | 20.mm2 As above, with both feather and tongue slots | 20.mm2a As above, with central bar across face |
20.mm2b) With central bar across face, tongue key only | 20.mm2c) As above, but cast alloy | 20.mm3.',400,342,'white')) All machined, tongue only, four spokes (weight 22g) | 20.mm4.',400,316,'white')) All faces machined, four holes instead of spokes (26g) |
20.go.',600,237,'white')) Lead alloy, 'gold' finished, boss with four buttresses (45g) | 20.mm5) Formed from two pressings, 1911 patent boss | 20.mm5a) As above but eight holes, 'Meccano patent' boss | 20.br1) As above but four holes, boss reversed from now on |
| 20.br1a As above but eight holes | 20.br2) As above but with standard-type boss, 9/32'' flange | 20.br2a) As above but with 7/32'' flange | 20.br2b) As above but outer rim smaller and rounded |
20.st) As above but steel face, bronzed. Rims similar sizes | 20.br3) No pulley section, one-part pressing 1 3/8'' dia. | 20.ni) As above, steel pressing nickel plated | 20.br3a) As .br3, sharp at flange/rim, flange under ¼'' |
| 20.br3b As above, larger, curve at flange/rim, flange ¼'' | 20.br4) As .br3 above, double-tapped | 20.br5 1 3/8'' diameter, ¼'' flange, double-tapped | 20.br5a) As above, squared-off rim and flange |
20.nb) 1 3/8'' diameter steel pressing, blue | 20.nb1) 1 3/8'' diameter steel pressing, blue with blue boss | 20.re) As above but red | 20.br.',400,336,'white')) As above but all brass (most common variety) |
20.bs) As above, but blackened steel † | 20.bk) Mazac one-piece casting, painted black † | 20.bk1) As above but brass boss | 20.br6 As above but all-brass casting |
20.zn) Cast alloy, zinc plated | 20.xx) Cast alloy with brass boss, raised lettering inside |
