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Crain's Scale / Gauge Encyclopedia
26 Scale Name:  9 mm Scale        
  Scale Ratio:  1:33.9    
  Alternate Names:  9 mm = 1 foot P34 Scale           
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
26 604  4ft 8.5in 56.5 33.9 0.354 9.0 1.667   42.33   0.0  
26 605  3.5 Foot 42 33.9 0.354 9.0 1.239   31.47   0.0  
26 606  Meter 39.4 33.9 0.354 9.0 1.162   29.52   0.0  
26 607  3 Foot 36 33.9 0.354 9.0 1.062   26.97   0.0  
26 608  2.5 Foot 30 33.9 0.354 9.0 0.885   22.48   0.0  
26 609  2 Foot 24 33.9 0.354 9.0 0.708   17.98   0.0  
26 610  15 Inch 15 33.9 0.354 9.0 0.442   11.24   0.0  
  Commonly Used Gauges    
26 611  1-3/4" Ga 56.5 33.9 0.354 9.0 1.766 1.820 44.86 46.23 6.0   Ga.1
26 612  45 mm Gauge 56.5 33.9 0.354 9.0 1.766 1.820 44.86 46.23 6.0   Ga.1
26 613  Gauge 1 56.5 33.9 0.354 9.0 1.766 1.820 44.86 46.23 6.0   Ga.1
26 614  1-1/4" Ga 42 33.9 0.354 9.0 1.250 1.285 31.75 32.64 0.9  Ostd 
26 615  O Ga Contl 42 33.9 0.354 9.0 1.260   32.00   1.7  
26 616  O Ga USA 42 33.9 0.354 9.0 1.250 1.285 31.75 32.64 0.9  Ostd 
26 616a  SM32 Gauge 42 33.9 0.354 9.0 1.250 1.285 31.75 32.64 0.9  Ostd 
26 617  Gauge 0 36 33.9 0.354 9.0 1.125   28.58   5.9  Ga.0
26 618  S Gauge 30 33.9 0.354 9.0 0.875 0.898 22.23 22.81 -1.1  Sstd
26 619  18 mm Gauge 24 33.9 0.354 9.0 0.750   19.05   5.9  
26 620  HO Gauge 24 33.9 0.354 9.0 0.649 0.672 16.48 17.07 -8.3  HOstd
               
Only a few mentions of this scale appear in the literature. Used in New  
Zealand to represent 42" gauge on O Gauge track.  
   
Crain's Scale / Gauge Encyclopedia
27 Scale Name:  1:35 Scale        
  Scale Ratio:  1:35    
  Alternate Names:  None                  
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
27 621  4ft 8.5in 56.5 35 0.343 8.71 1.614   41.00   0.0  
27 622  3.5 Foot 42 35 0.343 8.71 1.200   30.48   0.0  
27 623  Meter 39.4 35 0.343 8.71 1.126   28.59   0.0  
27 624  3 Foot 36 35 0.343 8.71 1.029   26.13   0.0  
27 625  2.5 Foot 30 35 0.343 8.71 0.857   21.77   0.0  
27 626  2 Foot 24 35 0.343 8.71 0.686   17.42   0.0  
27 627  15 Inch 15 35 0.343 8.71 0.429   10.89   0.0  
  Commonly Used Gauges    
27 628  1-3/4" Ga 56.5 35 0.343 8.71 1.766 1.820 44.86 46.23 9.4  Ga.1
27 629  45 mm Gauge 56.5 35 0.343 8.71 1.766 1.820 44.86 46.23 9.4  Ga.1
27 630  Gauge 1 56.5 35 0.343 8.71 1.766 1.820 44.86 46.23 9.4  Ga.1
27 631  1-1/4" Ga 42 35 0.343 8.71 1.250 1.285 31.75 32.64 4.2  Ostd 
27 632  O Ga Contl 42 35 0.343 8.71 1.260   32.00   5.0  
27 633  O Ga USA 42 35 0.343 8.71 1.250 1.285 31.75 32.64 4.2  Ostd 
27 634  Gauge 0 36 35 0.343 8.71 1.125   28.58   9.4  Ga.0
27 635  S Gauge 30 35 0.343 8.71 0.875 0.898 22.23 22.81 2.1 S std
27 636  HO Gauge 24 35 0.343 8.71 0.649 0.672 16.48 17.07 -5.4  HOstd
               
Only a few mentions of this scale appear in the literature. Used in France  
to represent 24" gauge on HO Gauge track. 1:35 scale is used  for military models.  
   
Crain's Scale / Gauge Encyclopedia
28 Scale Name:  8 mm Scale        
  Scale Ratio:  1:38.1 5/16 Inch Scale  
  Alternate Names:  8 mm = 1 foot              
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
28 637  4ft 8.5in 56.5 38.1 0.315 8.00 1.483   37.67   0.0  
28 638  Meter 39.4 38.1 0.315 8.00 1.034   26.27   0.0  
28 639  3 Foot 36 38.1 0.315 8.00 0.945   24.00   0.0  
28 640  2.5 Foot 30 38.1 0.315 8.00 0.787   20.00   0.0  
28 641  2 Foot 24 38.1 0.315 8.00 0.630   16.00   0.0  
28 642  15 Inch 15 38.1 0.315 8.00 0.394   10.00   0.0  
  Commonly Used Gauges  
28 643  1-3/4" Ga 66 38.1 0.315 8.00 1.766 1.820 44.86 46.23 1.9  Ga.1
28 644  45 mm Gauge 66 38.1 0.315 8.00 1.766 1.820 44.86 46.23 1.9  Ga.1
28 645  Gauge 1 66 38.1 0.315 8.00 1.766 1.820 44.86 46.23 1.9  Ga.1
28 646  1-1/4" Ga 48 38.1 0.315 8.00 1.250 1.285 31.75 32.64 -0.8  Ostd 
28 647  O Ga USA 48 38.1 0.315 8.00 1.250 1.285 31.75 32.64 -0.8  Ostd 
28 648  S Gauge 36 38.1 0.315 8.00 0.875 0.898 22.23 22.81 -7.4  Sstd
28 649  OO Gauge 30 38.1 0.315 8.00 0.750 0.772 19.05 19.61 -4.7  OOstd
28 650   5/16n2 Gauge 24 38.1 0.315 8.00 0.649 0.672 16.48 17.07 3.0  HOstd
28 651  HO Gauge 24 38.1 0.315 8.00 0.649 0.672 16.48 17.07 3.0  HOstd
   
Only a few mentions of this scale appear in the literature.  
   
Crain's Scale / Gauge Encyclopedia
29 Scale Name:  7 mm Scale  Scale 7        
  Scale Ratio:  1:43.5    
  Alternate Names:  7 mm = 1 foot British O Scale  Continental 0 Scale  
       Scale 7   European 0 Scale  Zero Scale    
       Number 0F Scale (Zero-Eff)     Naught Scale    
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
29 652  4ft 8.5in 56.5 43.5 0.276 7.0 1.299   32.99   0.0  
29 653  Meter 39.4 43.5 0.276 7.0 0.906   23.01   0.0  
29 654  3 Foot 36 43.5 0.276 7.0 0.828   21.02   0.0  
29 655  2.5 Foot 30 43.5 0.276 7.0 0.690   17.52   0.0  
29 656  2 Foot 24 43.5 0.276 7.0 0.552   14.01   0.0  
29 657  15 Inch 15 43.5 0.276 7.0 0.345   8.76   0.0  
  Commonly Used Gauges    
29 658  Scale 7 56.5 43.5 0.276 7.0 1.299   32.99   0.0  
29 659  0 Gauge/S7 56.5 43.5 0.276 7.0 1.299   32.99   0.0  
29 660  Fine 7 Ga 56.5 43.5 0.276 7.0 1.260   32.00   -3.0  
29 661  0 Ga Brit 56.5 43.5 0.276 7.0 1.260   32.00   -3.0  
29 662  0 Ga Contl 56.5 43.5 0.276 7.0 1.260   32.00   -3.0  
29 663  SM32 Gauge 56.5 43.5 0.276 7.0 1.260   32.00   -3.0  
29 664  O Ga USA 56.5 43.5 0.276 7.0 1.250 1.285 31.75 32.64 -3.8  Ostd 
29 665  1-1/4" Ga 56.5 43.5 0.276 7.0 1.250 1.285 31.75 32.64 -3.8  Ostd 
29 666  No.0F Ga 56.5 43.5 0.276 7.0 1.250 1.285 31.75 32.64 -3.8  Ostd 
29 667  43.5 / 32 Ga 56.5 43.5 0.276 7.0 1.250 1.285 31.75 32.64 -3.8  Ostd 
29 668  Gauge 0 56.5 43.5 0.276 7.0 1.125   28.58   ####  Ga.0
29 669  0n3.5 Ga 42 43.5 0.276 7.0 0.875 0.898 22.23 22.81 -9.4  Sstd
29 670  0m Gauge 39.4 43.5 0.276 7.0 0.875 0.898 22.23 22.81 -3.4  Sstd
29 671  43.5 / 22.5 Ga 39.4 43.5 0.276 7.0 0.875 0.898 22.23 22.81 -3.4  Sstd
29 672  S Gauge 39.4 43.5 0.276 7.0 0.875 0.898 22.23 22.81 -3.4  Sstd
29 673  0n3 Ga 36 43.5 0.276 7.0 0.875 0.898 22.23 22.81 5.7  Sstd
29 674  S Gauge 36 43.5 0.276 7.0 0.875 0.898 22.23 22.81 5.7  Sstd
29 674a  O21 Gauge 36 43.5 0.276 7.0 0.828   21.02   0.0  
29 675  O12 Gauge 36 43.5 0.276 7.0 0.750 0.772 19.05 19.61 -9.4  OOstd
29 676  OO Gauge 36 43.5 0.276 7.0 0.750 0.772 19.05 19.61 -9.4  OOstd
29 677  0n2.5 Ga 30 43.5 0.276 7.0 0.689   17.50   -0.1  
29 677a  0n30 Ga 30 43.5 0.276 7.0 0.689   17.50   -0.1  
29 678  HO Gauge 30 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -5.9  HOstd
29 679  O-16.5 Ga 30 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -5.9  HOstd
29 680  Oe16.5 Ga 30 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -5.9  HOstd
29 681  OOn Gauge 30 43.5 0.276 7.0 0.750 0.772 19.05 19.61 8.7  OOstd
29 682  0m750 Ga 29.5 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -4.3  HOstd
29 683  0e Gauge 29.5 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -4.3  HOstd
29 684  43.5 / 16.5 Ga 29.5 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -4.3  HOstd
29 684a  O16.5 Ga 29.5 43.5 0.276 7.0 0.649 0.672 16.48 17.07 -4.3  HOstd
29 685  O16.5 Gauge 28 43.5 0.276 7.0 0.649 0.672 16.48 17.07 4.6  HOstd
29 685a  HO Gauge 27 43.5 0.276 7.0 0.649 0.672 16.48 17.07 4.6  HOstd
29 686  OOn Gauge 27 43.5 0.276 7.0 0.750 0.772 19.05 19.61 20.8  OOstd
29 687  0Fn27 Ga 27 43.5 0.276 7.0 0.620   15.75   -0.1  
29 688  0n2 Gauge 24 43.5 0.276 7.0 0.551   14.00   -0.1  
29 689  0e14 Gauge 24 43.5 0.276 7.0 0.551   14.00   -0.1  
29 689a  O14 Gauge 24 43.5 0.276 7.0 0.551   14.00   -0.1  
29 690  TT Gauge 18 43.5 0.276 7.0 0.471 0.483 11.96 12.27 13.8  TTstd
29 690a  O-12 Gauge 18 43.5 0.276 7.0 0.471 0.483 11.96 12.27 13.8  TTstd
29 691  0n15 Gauge 15 43.5 0.276 7.0 0.413   10.49   -0.2  
29 692  N Gauge 15 43.5 0.276 7.0 0.353 0.367 8.97 9.32 2.4  Nstd
29 693  0n15 Gauge 15 43.5 0.276 7.0 0.344   8.74   -0.2  
29 693a  O9 Gauge 18 43.5 0.276 7.0 0.344   8.74   -0.2  
   
This is one of several scales near 1/4 inch to the foot. The "Zero" or  
"Naught" in the scale name is often mistaken for an "Oh". This is a British  
and European version of O Scale. The "F" stands for Fine Scale.  
   
Crain's Scale / Gauge Encyclopedia
30 Scale Name:  Continental 0 Scale   OJ Scale    
  Scale Ratio:  1:45    
  Alternate Names:  Continental O Scale  "Zero" not "Oh"      
       17/64 Inch Scale  23 mm - 1 meter (France)
       Q Scale (in Europe) "Que" not "Oh"        
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
30 694  4ft 8.5in 56.5 45 0.267 6.77 1.256   31.89   0.0  
30 695  Meter 39.4 45 0.267 6.77 0.876   22.24   0.0  
30 696  3 Foot 36 45 0.267 6.77 0.800   20.32   0.0  
30 697  2.5 Foot 30 45 0.267 6.77 0.667   16.93   0.0  
30 698  2 Foot 24 45 0.267 6.77 0.533   13.55   0.0  
30 699  15 Inch 15 45 0.267 6.77 0.333   8.47   0.0  
  Commonly Used Gauges    
30 700  O17 Gauge 56.5 45 0.267 6.77 1.250 1.285 31.75 32.64 -0.4  Ostd 
30 701  0 Ga Brit 56.5 45 0.267 6.77 1.260   32.00   0.4  
30 702  O Ga Contl 56.5 45 0.267 6.77 1.260   32.00   0.4  
30 703  O Ga USA 56.5 45 0.267 6.77 1.250 1.285 31.75 32.64 -0.4  Ostd 
30 704  1-1/4" Ga 56.5 45 0.267 6.77 1.250 1.285 31.75 32.64 -0.4  Ostd 
30 705  45 / 32 Ga 56.5 45 0.267 6.77 1.250 1.285 31.75 32.64 -0.4  Ostd 
30 706  Gauge 0 56.5 45 0.267 6.77 1.125   28.58   ####  Ga.0
30 707  O17m Gauge 39.4 45 0.267 6.77 0.875 0.898 22.23 22.81 -0.1  Sstd
30 708  0m Gauge 39.4 45 0.267 6.77 0.875 0.898 22.23 22.81 -0.1  Sstd
30 709  45 / 22.5 Ga 39.4 45 0.267 6.77 0.875 0.898 22.23 22.81 -0.1  Sstd
30 710  S Gauge 39.4 45 0.267 6.77 0.875 0.898 22.23 22.81 -0.1  Sstd
30 711  On3 Gauge 36 45 0.267 6.77 0.875 0.898 22.23 22.81 9.4  Sstd
30 712  S Gauge 36 45 0.267 6.77 0.875 0.898 22.23 22.81 9.4  Sstd
30 713  On3 Gauge 36 45 0.267 6.77 0.750 0.778 19.05 19.76 -6.3  On3
30 714  45 / 19 Ga 36 45 0.267 6.77 0.750 0.778 19.05 19.76 -6.3  On3
30 715  0m750 Ga 29.5 45 0.267 6.77 0.649 0.672 16.48 17.07 -1.0  HOstd
30 716  0m75 Ga 29.5 45 0.267 6.77 0.649 0.672 16.48 17.07 -1.0  HOstd
30 717  0e Gauge 29.5 45 0.267 6.77 0.649 0.672 16.48 17.07 -1.0  HOstd
30 718  45 / 16.5 Ga 29.5 45 0.267 6.77 0.649 0.672 16.48 17.07 -1.0  HOstd
30 719  HO Gauge 27 45 0.267 6.77 0.649 0.672 16.48 17.07 8.2  HOstd
30 720  Oe16.5 Ga 27 45 0.267 6.77 0.649 0.672 16.48 17.07 8.2  HOstd
30 721  0n2 Gauge 24 45 0.267 6.77 0.551   14.00   3.3  
30 722  HO Gauge 24 45 0.267 6.77 0.649 0.672 16.48 17.07 21.7  HOstd
30 723  0e14 Gauge 24 45 0.267 6.77 0.551   14.00   3.3  
30 723a  N Gauge 15 45 0.267 6.77 0.353 0.367 8.97 9.32 2.4  Nstd
30 723b  0n15 Gauge 15 45 0.267 6.77 0.344   8.74   -0.2  
30 723ca  Op Gauge 15 45 0.267 6..77 0.344   8.74   -0.2  
   
Continental O Scale uses a wider track gauge and larger ratio than USA O  
Scale. In the USA, O17 Scale (17/64 inches = 1 foot) is almost identical.  
   
Crain's Scale / Gauge Encyclopedia
31 Scale Name:  O17 Scale        
  Scale Ratio:  1:45.2    
  Alternate Names:  17/64 inch  = 1 foot 17/64 Scale ("Oh" not "Zero")  
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
31 724  4ft 8.5in 56.5 45.2 0.265 6.74 1.250   31.75   0.0  
31 725  Meter 39.4 45.2 0.265 6.74 0.872   22.14   0.0  
31 726  3 Foot 36 45.2 0.265 6.74 0.796   20.23   0.0  
31 727  2.5 Foot 30 45.2 0.265 6.74 0.664   16.86   0.0  
31 728  2 Foot 24 45.2 0.265 6.74 0.531   13.49   0.0  
31 729  15 Inch 15 45.2 0.265 6.74 0.332   8.43   0.0  
  Commonly Used Gauges    
31 730  O17 Gauge 56.5 45.2 0.265 6.74 1.250 1.285 31.75 32.64 0.0  Ostd 
31 731  0 Ga Brit 56.5 45.2 0.265 6.74 1.260   32.00   0.8  
31 732  O Ga Contl 56.5 45.2 0.265 6.74 1.260   32.00   0.8  
31 733  O Ga USA 56.5 45.2 0.265 6.74 1.250 1.285 31.75 32.64 0.0  Ostd 
31 734  1-1/4" Ga 56.5 45.2 0.265 6.74 1.250 1.285 31.75 32.64 0.0  Ostd 
31 735  45.2 / 32 Ga 56.5 45.2 0.265 6.74 1.250 1.285 31.75 32.64 0.0  Ostd 
31 736  Gauge 0 56.5 45.2 0.265 6.74 1.125   28.58   ####  Ga.0
31 737  O17m Gauge 39.4 45.2 0.265 6.74 0.875 0.898 22.23 22.81 0.4  Sstd
31 738  S Gauge 39.4 45.2 0.265 6.74 0.875 0.898 22.23 22.81 0.4  Sstd
31 739  On3 Gauge 36 45.2 0.265 6.74 0.750 0.778 19.05 19.76 -5.8  On3
31 740  S Gauge 36 45.2 0.265 6.74 0.875 0.898 22.23 22.81 9.9  Sstd
31 741  HO Gauge 30 45.2 0.265 6.74 0.649 0.672 16.48 17.07 -2.2  HOstd
31 741  Oe Gauge 30 45.2 0.265 6.74 0.649 0.672 16.48 17.07 -2.2  HOstd
31 742  0n30 Gauge 30 45.2 0.265 6.74 0.650   16.51   -2.1  
31 744  0n2 Gauge 24 45.2 0.265 6.74 0.551   14.00   3.8  
31 743  HO Gauge 24 45.2 0.265 6.74 0.649 0.672 16.48 17.1 22.2  HOstd
31 743a  9 mm Gauge 18 45.2 0.265 6.74 0.353 0.367 8.97 9.32 -5.9  Nstd
31 743b  45 / 9 Gauge 18 45.2 0.265 6.74 0.353 0.367 8.97 9.32 -5.9  Nstd
31 743c  N Gauge 18 45.2 0.265 6.74 0.353 0.367 8.97 9.32 -5.9  Nstd
       
This scale name is easily mistaken in print for O-27 gauge, which is the name for Lionel  
tinplate, 27 inch diameter O gauge hi-rail track.  
       
Crain's Scale / Gauge Encyclopedia
32 Scale Name:  USA O Scale        
  Scale Ratio:  1:48    
  Alternate Names:  1/4 inch  = 1 foot   1/4 Inch Scale ("Oh" not "Zero")
       1/4 Inch Scale   1:48 Scale        
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
32 745  4ft 8.5in 56.5 48 0.250 6.35 1.177   29.90   0.0  
32 746  Meter 39.4 48 0.250 6.35 0.821   20.85   0.0  
32 747  3.5 Foot 42 48 0.250 6.35 0.875   22.23   0.0  
32 748  3 Foot 36 48 0.250 6.35 0.750   19.05   0.0  
32 749  2.5 Foot 30 48 0.250 6.35 0.625   15.88   0.0  
32 750  2 Foot 24 48 0.250 6.35 0.500   12.70   0.0  
32 751  15 Inch 15 48 0.250 6.35 0.313   7.94   0.0  
 Hi-rail, 3-rail, Tinplate Version  
32 752  O HiRail 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel  generic
32 753  O-27 Track 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 27 in dia lt wt
32 754  O-27-42 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 42 in dia
32 755  O-27-54 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 54 in dia
32 756  O-27-72 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 72 in dia
32 757  O-31 Track 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 31 in dia hvy wt
32 758  O-42 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 42 in dia
32 759  O-54 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 54 in dia
32 760  O-72 56.5 48 0.250 6.35 1.250 1.280 31.8 32.51 6.2  Lionel 72 in dia
             
Tru-Track and T-Rail are other Lionel (rare) track types with various radius curves. Several    
other manufactures make O HiRail track with various geometries. Some HiRail    
locomotives will not run on all track types. A physical test run is required.    
   
Q Scale USA  ("Que" not "Oh")  
32 761  Q Gauge 56.5 48 0.250 6.35 1.188   30.2   0.9  
32 762  Bing OO 56.5 48 0.250 6.35 1.125   28.6   -4.4  
32 763  Gauge 0 56.5 48 0.250 6.35 1.125   28.6   -4.4  Ga.0
32 764  1/4 AAR 56.5 48 0.250 6.35 1.177 1.205 29.90 30.61 0.0  
32 765  Proto 48 56.5 48 0.250 6.35 1.177 1.205 29.90 30.61 0.0  
             
Q (Que) Scale is O (Oh) Scale with correct track gauge. Replaced by 1/4 AAR and Proto 48.
   
O Scale USA  ("Oh" not "Que")  
32 766  O Broad 60 48 0.250 6.35 1.250 1.285 31.75 32.64 0.0  Ostd 
32 767  Ow5 Gauge 60 48 0.250 6.35 1.250 1.285 31.75 32.64 0.0  Ostd 
32 768  0 Ga Brit 56.5 48 0.250 6.35 1.260   32.00   7.0  
32 769  SM32 Gauge 56.5 48 0.250 6.35 1.260   32.00   7.0  
32 770  O Ga Contl 56.5 48 0.250 6.35 1.260   32.00   7.0  
32 771  O Ga USA 56.5 48 0.250 6.35 1.250 1.285 31.75 32.64 6.2 Ostd 
32 772  1-1/4" Ga 56.5 48 0.250 6.35 1.250 1.285 31.75 32.64 6.2  Ostd 
32 773  48 / 32 Ga 56.5 48 0.250 6.35 1.250 1.285 31.75 32.64 6.2  Ostd 
32 774  Q Gauge 56.5 48 0.250 6.35 1.188   30.18   0.9  
32 775  1/4 AAR 56.5 48 0.250 6.35 1.177 1.205 29.90 30.61 0.0  
32 776  Proto 48 56.5 48 0.250 6.35 1.177 1.205 29.90 30.61 0.0  
32 777  O Fine Ga 56.5 48 0.250 6.35 1.177 1.205 29.90 30.61 0.0  
32 778  S Gauge 56.5 48 0.250 6.35 0.875 0.898 22.23 22.81 -20.0  Sstd
32 779  Gauge 0 56.5 48 0.250 6.35 1.125   28.58   -4.4  Ga.0
32 780   1/4 AAR-49 49 48 0.250 6.35 1.000   25.40   -2.0  
32 781  On3.5 Ga 42 48 0.250 6.35 0.875 0.898 22.23 22.81 0.0  Sstd
32 782  S Gauge 42 48 0.250 6.35 0.875 0.898 22.23 22.81 0.0  Sstd
32 783  Om Gauge 39.4 48 0.250 6.35 0.750 0.772 19.05 19.61 -8.6  OOstd
32 784  OO Gauge 39.4 48 0.250 6.35 0.750 0.772 19.05 19.61 -8.6  OOstd
32 785  48 / 19 Ga 39.4 48 0.250 6.35 0.750 0.772 19.05 19.61 -8.6  OOstd
32 786  S Gauge 39.4 48 0.250 6.35 0.875 0.898 22.23 22.81 6.6  Sstd
32 787  OO Gauge 36 48 0.250 6.35 0.750 0.772 19.05 19.61 0.0  OOstd
32 788  On3 Gauge 36 48 0.250 6.35 0.750 0.778 19.05 19.76 0.0  On3
32 789  Proto 48n3 36 48 0.250 6.35 0.750 0.778 19.05 19.76 0.0  On3
32 790  OO Gauge 36 48 0.250 6.35 0.750 0.772 19.05 19.61 0.0  OOstd
32 791  48 / 19 Ga 36 48 0.250 6.35 0.750 0.772 19.05 19.61 0.0  On3
32 792  O-16.5 Ga 30 48 0.250 6.35 0.649 0.672 16.48 17.07 3.8  HOstd
32 793  HO Gauge 30 48 0.250 6.35 0.649 0.672 16.48 17.07 3.8  HOstd
32 794  On2.5 Ga 30 48 0.250 6.35 0.649 0.672 16.48 17.07 3.8  HOstd
32 795  On30 Gauge 30 48 0.250 6.35 0.649 0.672 16.48 17.07 3.8  HOstd
32 796  48 / 16.5 Ga 30 48 0.250 6.35 0.649 0.672 16.48 17.07 3.8  HOstd
32 797  Om750 Ga 29.5 48 0.250 6.35 0.649 0.672 16.48 17.07 5.6  HOstd
32 798  Om75 Ga 29.5 48 0.250 6.35 0.649 0.672 16.48 17.07 5.6  HOstd
32 799  Oe Gauge 29.5 48 0.250 6.35 0.649 0.672 16.48 17.07 5.6  HOstd
32 800  Oe16.5 Ga 27 48 0.250 6.35 0.649 0.672 16.48 17.07 15.4  HOstd
32 801  HO Gauge 27 48 0.250 6.35 0.649 0.672 16.48 17.07 15.4  HOstd
32 802  On27 Ga 27 48 0.250 6.35 0.563   14.30   0.1  
32 803  On2 Gauge 24 48 0.250 6.35 0.500 0.522 12.70 13.26 0.0  On2
32 804  48 / 12.7 Ga 24 48 0.250 6.35 0.500 0.522 12.70 13.26 0.0  On2
32 805  TT Gauge 24 48 0.250 6.35 0.471 0.483 11.96 12.27 -5.8  TTstd
32 806  48 / 12 Ga 24 48 0.250 6.35 0.471 0.483 11.96 12.27 -5.8  TTstd
32 807  On20 Gauge 20 48 0.250 6.35 0.417   10.59   0.1  HOn3
32 808  HOn3 Gauge 20 48 0.250 6.35 0.413 0.429 10.49 10.90 -0.9  HOn3
32 809  On18 Gauge 18 48 0.250 6.35 0.375   9.53   0.0  
32 810  9 mm Gauge 18 48 0.250 6.35 0.353 0.367 8.97 9.32 -5.9  Nstd
32 811  48 / 9 Gauge 18 48 0.250 6.35 0.353 0.367 8.97 9.32 -5.9  Nstd
32 812  N Gauge 18 48 0.250 6.35 0.353 0.367 8.97 9.32 -5.9  Nstd
   
This is the popular American version of O Scale. Considerable amounts of  
equipment and parts are commercially available.  
   
Crain's Scale / Gauge Encyclopedia
33 Scale Name:  Number 0 Scale      
  Scale Ratio:  1:50 Continental O Scale but see Table 30
  Alternate Names:  20 mm = 1 meter  0j Scale ("Zero" or "Naught" not "Oh")
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
33 813  4ft 8.5in 56.5 50 0.240 6.10 1.130   28.70   0.0  
33 814  Meter 39.4 50 0.240 6.10 0.788   20.02   0.0  
33 815  3 Foot 36 50 0.240 6.10 0.720   18.29   0.0  
33 816  2.5 Foot 30 50 0.240 6.10 0.600   15.24   0.0  
33 817  2 Foot 24 50 0.240 6.10 0.480   12.19   0.0  
33 818  15 Inch 15 50 0.240 6.10 0.300   7.62   0.0  
  Commonly Used Gauges ("Gauge Zero")  
33 819  O Ga Brit 56.5 50 0.240 6.10 1.260   32.00   11.5  
33 820  O Ga Contl 56.5 50 0.240 6.10 1.260   32.00   11.5  
33 821  O Ga USA 56.5 50 0.240 6.10 1.250 1.285 31.75 32.64 10.6  Ostd 
33 822  1-1/4" Ga 56.5 50 0.240 6.10 1.250 1.285 31.75 32.64 10.6  Ostd 
33 823  50 / 32 Ga 56.5 50 0.240 6.10 1.250 1.285 31.75 32.64 10.6  Ostd 
33 824  Bing OO 56.5 50 0.240 6.10 1.125   28.58   -0.4  Ga.0
33 825  Gauge 0 56.5 50 0.240 6.10 1.125   28.58   -0.4  Ga.0
33 826  No.0n3.5 42 50 0.240 6.10 0.875 0.898 22.23 22.81 4.2  Sstd
33 827  S Gauge 42 50 0.240 6.10 0.875 0.898 22.23 22.81 4.2  Sstd
33 828  No.0m Ga 39.4 50 0.240 6.10 0.750 0.772 19.05 19.61 -4.8  OOstd
33 829  OO Gauge 39.4 50 0.240 6.10 0.750 0.772 19.05 19.61 -4.8  OOstd
33 829a  EM Gauge 39.4 50 0.240 6.10 0.750 0.772 19.05 19.61 -4.8  OOstd
33 830  No.0n3 Ga 36 50 0.240 6.10 0.750 0.772 19.05 19.61 4.2  OOstd
33 831  OO Gauge 36 50 0.240 6.10 0.750 0.772 19.05 19.61 4.2  OOstd
   
Primarily, this is a toy train scale, but some modeling is done because the  
scale ratio is neat and track is available. Also used for scale models in Japan.  
   
Crain's Scale / Gauge Encyclopedia
34 Scale Name:  5.5 mm Scale        
  Scale Ratio:  1:55.4    
  Alternate Names:  5.5 mm = 1 foot              
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
34 832  4ft 8.5in 56.5 55.4 0.217 5.50 1.020   25.90   0.0  
34 833  Meter 39.4 55.4 0.217 5.50 0.711   18.06   0.0  
34 834  3 Foot 36 55.4 0.217 5.50 0.650   16.51   0.0  
34 835  2.5 Foot 30 55.4 0.217 5.50 0.542   13.75   0.0  
34 836  2 Foot 24 55.4 0.217 5.50 0.433   11.00   0.0  
  Commonly Used Gauges  
34 837  H1 Gauge 48 55.4 0.217 5.50 0.875 0.898 22.23 22.81 1.0  Sstd
34 838  S Gauge 48 55.4 0.217 5.50 0.875 0.898 22.23 22.81 1.0  Sstd
34 839  HO Gauge 36 55.4 0.217 5.50 0.649 0.672 16.48 17.07 -0.1  HOstd
34 840  Fn3 Gauge 36 55.4 0.217 5.50 0.649 0.672 16.48 17.07 -0.1  HOstd
34 841  TT3n Gauge 27 55.4 0.217 5.50 0.471 0.483 11.96 12.27 -3.4  TTstd
34 842  TT Gauge 27 55.4 0.217 5.50 0.471 0.483 11.96 12.27 -3.4  TTstd
   
This is definitely an oddball British scale, attempting to use TT Gauge track  
in a larger scale for modeling industrial scenes (Welsh). Also called I0m????  
The Fn3 Gauge listed above is not related to F Scale.  
   
Crain's Scale / Gauge Encyclopedia
35 Scale Name:  5 mm Scale  ZO Scale (1:60)       
  Scale Ratio:  1:61    
  Alternate Names:  T Scale (twice the size of TT Scale)  
     5 mm = 1 foot 1/5 inch Scale 1/5 inch = 1 foot    
     Represented    Scale       Model Track Gauge Error  Track
  Ser #     Gauge  Inches Ratio   In/ft  mm/ft       Inches           mm %  Used
  Correct Gauge:      
35 843  4ft 8.5in 56.5 61 0.197 5.00 0.926   23.53   0.0  
35 844  Meter 39.4 61 0.197 5.00 0.646   16.41   0.0  
35 845  3 Foot 36 61 0.197 5.00 0.590   14.99   0.0  
35 846  2.5 Foot 30 61 0.197 5.00 0.492   12.49   0.0  
35 847  2 Foot 24 61 0.197 5.00 0.393   9.99   0.0  
  Commonly Used Gauges        
35 848  1" Gauge 56.5 61 0.197 5.00 1.000   25.40   8.0  
35 849  H1 Gauge 56.5 61 0.197 5.00 0.875 0.898 22.23 22.81 -5.5  Sstd
35 850  S Gauge 56.5 61 0.197 5.00 0.875 0.898 22.23 22.81 -5.5  Sstd
35 851  HO Gauge 39.4 61 0.197 5.00 0.649 0.672 16.48 17.07 0.5  HOstd
35 852  TT Gauge 27 61 0.197 5.00 0.471 0.483 11.96 12.27 6.4  TTstd
   
This scale uses HO Gauge to represent Meter Gauge industrial trackage.
 

 

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