Standard S3.5: Track - Narrow Gauge

Track Gauge minimum	Gmin	0.563"	14.30mm
Track Guage maximum	Gmax	0.585"	14.86mm
Check Gauge minimum	Cmin	0.519"	13.18mm
Span maximum	Smax	0.478"	12.14mm
Flangeway maximum	Fmax	0.050"	1.27mm
Flange Height minimum	Hmin	0.030"	0.76mm
Point Spread maximum	Pmax (E) Electrical	0.499"	12.68mm

Standards and Clearance Diagrams

• Track and Wheel Standards - NASG/NMRA standards
  • Track, Standard Gauge S 3
  • Track, Narrow Gauge S 3.5
  • Wheels, Standard Gauge S 4
  • Wheels, Narrow Gauge S 4.5
  • Track, Proto: 64 RP 3
  • Wheels, Proto: 64 RP 4
  • The NASG Clearinghouse offers track and wheel gauges for S standard gauge.
• NMRA Standards
  • standard-gauge NMRA turnout dimensions (RP 12.3)
  • The NMRA recommended practice for car weight is 2 oz. plus another 1/2 oz. per inch of car length.
  • Sn3 track and wheel gauges are available from the NMRA.
• Clearance Diagrams and Gauges
  • older (pre-stack car era) clearance template (PDF)
  • newer " Plate H" clearance template (PDF)
  • If you prefer to purchase a clearance gauge instead of making one, S clearance gauges are available from banta modelworks made of either wood or acrylic.