What is gauge scale?

Answer 1

Gauge can apply to the the sizes of model railroad trains originated in this fashion: size gauge 3 2 1/2 inch 2 2 inch 1 1 3/4 inch O 1 1/4 inch OO 16.5 mm OOO 9.5 mm Here are the common one for model trains. name gauge scale G 45 mm 1:22.5 O 1 1/4 " 1:48 S 7/8 " 1:64 OO 16.5 mm 1:76.2 (exactly) (4 mm to the foot) HO 16.5 mm 1:87.0857... (3.5 mm to the foot) TT 12 mm 1:101.6 (exactly) (3 mm to the foot) N 9 mm 1:160 Z 6.5 mm 1:20 It is also used for needles sizes and those are listed below: The columns are nominal OD in mm and inches then nominal ID in the same units. 10 3.404 0.1340 ±0.0010 2.692 0.1060 ±0.0020 11 3.048 0.1200 " 2.388 0.0940 " 12 2.769 0.1090 " 2.159 0.0850 " 13 2.413 0.0950 " 1.803 0.0710 " 14 2.108 0.0830 " 1.600 0.0630 " 15 1.829 0.0720 ±0.0005 1.372 0.0540 ±0.0015 16 1.651 0.0650 " 1.194 0.0470 " 17 1.473 0.0580 " 1.067 0.0420 " 18 1.270 0.0500 " 0.838 0.0330 " 19 1.067 0.0420 " 0.686 0.0270 " 20 0.902 0.0355 +0.0005 -0.0000 0.584 0.0230 +0.0015 -0.0000 21 0.813 0.0320 " 0.495 0.0195 " 22 0.711 0.0280 " 0.394 0.0155 " 22s 0.711 0.0280 " 0.140 0.0055 " 23 0.635 0.0250 " 0.318 0.0125 " 24 0.559 0.0220 " 0.292 0.0115 " 25 0.508 0.0200 " 0.241 0.0095 " 25s 0.508 0.0200 " 0.140 0.0055 " 26 0.457 0.0180 " 0.241 0.0095 " 26s 0.467 0.0184 " 0.114 0.0045 " 27 0.406 0.0160 " 0.191 0.0075 " 28 0.356 0.0140 " 0.165 0.0065 " 29 0.330 0.0130 " 0.165 0.0065 " 30 0.305 0.0120 " 0.140 0.0055 " 31 0.254 0.0100 " 0.114 0.0045 " 32 0.229 0.0090 " 0.089 0.0035 " 33 0.203 0.0080 " 0.089 0.0035 "