Crankshaft Grinding
HM GEM provide a cost effective crankshaft reconditioning service. When a crankshaft arrives at HM Gem a full survey report is completed. Non destructive magnetic particle crack testing, rockwell hardness testing, journal and radii measurements are all recorded to establish the components viability for reuse. Where required shafts can be etch checked to ensure no grinder burn is evident which may lead to a premature failure.
It is only after all these checks are completed that the machining process takes place. Crankshafts up to 4000mm in length with a 300mm stroke can be accommodated. HM Gem can also offer cost effective seal surface reclamation solutions.
Crankshaft Inspection / Crankshaft Crack testing
All crankshafts have gallery plugs removed and are chemically cleaned to ensure all oil feed gallerries are free from oil sludging and frogien material contimination. A full survey report is completed on every crankshaft.
The inspection process includes, non destructive magnetic particle crack testing, Rockwell hardness testing, crankshaft bend checking (T.I.R. Total Indicator Runout). All journal radii are examined and all journals are checked for sizing, taper and ovality, finally the shaft is de-magnetised.
Crankshaft magnetic particle crack testing.
Crankshaft hardness testing.
Crankshaft journal size measuring.
Crankshaft fillet radius inspection.
Crankshaft being demagnetised
Crankshaft Grinding / Polishing and Final Inspection
Crankshaft up to 4000mm in length with a 300mm stroke can be ground to the next available undersize. All journal machining is carried out as per the manufacturers exacting tolerances, fillet radii are dressed and the crankshaft is micro polished. On completion of the machining process a closing report with specifications and finished sizes can be supplied.


Note machined coolant tracks in grinding wheel ensuring thrust face and radius overheating during the machining process is eliminated.
Also shown is the automatic sizing gauge with electronic in-process control and LCD display panel.
Cummins QSK crankshaft set on AMC Schou K3700 grinding machine.
Cummins NT Crankshaft completed and preserved ready for despatch.