2008 NMRA Convention - Anaheim. California logo

S-4.3, Wheels, Scales with Deep Flanges

S-4.3

S-4.1
Scale Scale Ratio Standard S4.3 Wheels using Target and Asymmetric Tolerance
K B N D T
Wheel Check Gage Back-to-Back Width Depth Flange Width
Target Plus Minus Target Plus Minus Min Max Nom Tol
G 1:20.3 1.656 0.004 0.015 1.582 0.004 0.015 0.271 0.118 0.074 +/-0.002
1:22.5
1:24
1:29
1:32
OHI 1:48 1.153 0.003 0.005 1.090 0.003 0.005 0.230 0.095 0.063 +/-0.002
O27 1:48 1.153 0.003 0.005 1.090 0.003 0.005 0.230 0.095 0.063 +/-0.002
SHi 1:64 0.774 0.003 0.004 0.709 0.003 0.004 0.172 0.095 0.065 +/-0.002

NOTES:

  1. For information on both minimum and maximum manufacturing limits please see NMRA Tech Note: TN-1.2.1 (In work)
  2. For dimensions not listed please see S-4.2 #I scale wheels.
  3. G models typically have a minimum tire width of .271.
  4. Truck BOLSTERS (S HI-RAIL only):
    Low Bolster: Freight car trucks: 13/32" Passenger car trucks: 1/2"
    High Bolster: All Trucks: 5/8"
  5. RP-25 contours or some other form of fillet are highly recommended for all wheels for increased reliability. The fillet acts to keep the wheels centered on the rails and significantly reduces derailments. Hi-Rail scale Wheels often do not conform to the contours and dimensions of RP-25, so Flange Thickness T is listed above. Contours typically have no fillet radius between Flange and Tread, and Flange tapers on one or both sides
  6. B represents a minimum value. The actual value can be larger. For example, the preferred manufacturing dimension for G Gauge is 1.575.