Commonwealth Railways NM class

{{Short description|Class of diesel locomotives}}

{{Use Australian English|date=May 2014}}

{{Use dmy dates|date=May 2014}}

{{Infobox locomotive

|name = Commonwealth Railways NM class

|powertype = Steam

|image = NM 34.jpg

|alt =

|caption = Preserved NM34 at the National Railway Museum in October 2010

|designer =

|builder = Thompson & Co, Castlemaine

|ordernumber =

|serialnumber =

|buildmodel =

|builddate = 1925-1927

|totalproduction = 22

|rebuilder =

|rebuilddate =

|numberrebuilt =

|whytetype = {{whyte|4-8-0}}

|uicclass =

|gauge = {{RailGauge|1067mm|lk=on}}

|leadingdiameter =

|driverdiameter =

|trailingdiameter =

|minimumcurve =

|wheelbase =

|length =

|width =

|height =

|axleload =

|weightondrivers =

|locoweight =

|tenderweight =

|locotenderweight =

|tendertype =

|fueltype = Coal

|fuelcap =

|watercap =

|tendercap =

|sandcap =

|boiler =

|boilerpressure = {{convert|160|psi|bar kPa|abbr=on}}

|feedwaterheater =

|firearea = {{convert|18.5|sqft|m2|abbr=on}}

|tubearea =

|fluearea =

|tubesandflues =

|fireboxarea =

|totalsurface =

|superheatertype =

|superheaterarea =

|cylindercount =

|cylindersize = {{convert|17|x|22|in|mm|0|abbr=on}}

|frontcylindersize=

|rearcylindersize =

|hpcylindersize =

|lpcylindersize =

|valvegear =

|valvetype =

|valvetravel =

|valvelap =

|valvelead =

|transmission =

|maxspeed =

|poweroutput =

|tractiveeffort = {{convert|18,085|lbf|kN|abbr=on}}

|factorofadhesion =

|trainheating =

|locobrakes =

|locobrakeforce =

|trainbrakes =

|safety =

|operator = Commonwealth Railways

|operatorclass =

|powerclass =

|numinclass =

|fleetnumbers = NM15-NM28
NM31-NM38

|officialname =

|nicknames =

|axleloadclass =

|locale =

|deliverydate =

|firstrundate = June 1925

|lastrundate =

|retiredate =

|withdrawndate =

|preservedunits =NM25, NM34

|restoredate =

|scrapdate =

|currentowner = National Railway Museum
Pichi Richi Railway

|disposition = 2 preserved, 20 scrapped}}

The Commonwealth Railways NM class locomotive was a class of {{whyte|4-8-0}} locomotives of the Commonwealth Railways, Australia. The class operated on {{RailGauge|1067mm}} narrow gauge lines in South Australia and the Northern Territory.