Novak Shafts

While the methods used to build the Novak conversion and replacement shafts have advanced, the end results are always the same; impeccable shafts made of the best steel and toleranced to exacting standards of precision.

Hardness Testing
In-house precision grinding and hardness testing of our geartrain components are additional elements that set us apart. We are able to send out each shaft with the confidence it will be stronger, last longer and run quieter than the rest.

Virtually every step of the shaft building process occurs within our own facility, including:

  • Tool design and manufacture
  • Lathe turning the shafts to profile
  • All splining operations, using various cutting, and shaping methods
  • Media blasting
  • Precision grinding, for superior bearing and seal grade surfaces

Our shafts begin with various alloys of steel - some of gear steels, and some of power transmission alloys. They are lathe turned to precision. The next step for our transmission shafts is the splining process. Careful methods and reliable equipment allow us to excel in these steps. Once splined, the shafts leave our site for the hardening processes in an aerospace certified facility. Depending on the application, they acheive 45 to 64 Rockwell C. Once back at Novak, we are able to test each batch with an in-house hardness tester to verify whether they will move on to the final stages of machining.

Shafts, green and ready for hardening
A batch of "green" T18 shafts just before the hardening process. Where other companies chince on materials and methods of manufacture, we go all out.

Hardness, lost Precision, hardness
A close-up of a competitor's T18 mainshaft pilot tip and third gear surface after minimal use. Shallow and insufficient hardening caused the demise of an otherwise excellent transmission. This shaft also exhibits lack of grinding on gear surfaces, forcing the gears themselves to lap the surfaces smooth. Precision ground finishes on the gear surfaces are readily apparent, in addition to the pilot tip. This shaft's virtues are more than skin deep - the specially hardened surfaces will hold up longer than even OEM units. The competition's shafts are hardly even in the running.

Broken, friction welded
Friction welding just doesn't cut it. For our automatic shafts, we start with a bar of 4340 alloy steel, machine it like wild, and then follow with two heat treating processes with precision hard-turning in the interim.

These efforts matter, absolutely.


Contract Shaft Machining
Novak does do contract machining for companies requiring power transmission shafting. We welcome companies' inquiries.

Power transmission spline shafts

A sampling of our shaft manufacturing capabilities, featuring:

  • External involute splines, disc shaped
  • Internal involute splines, shank shaped
  • External involute splines, single side cut
  • External straight splines, single side cut
  • Internal keyways, single point shaped
  • External keyways, milled
  • Hydraulic flow port cross drilling
  • Gun drilling
  • 4-axis CNC worm drive gear cutting
  • Carburized surfaces from .035" to .050" depths and 60RC hardness
  • Double heat-treated alloys with nitride case hardening
  • Precision ground or PCBN hard-turned surfaces from 16 to 8 micron finishes
  • Cylindrical tolerances to .0002"
  • Cold Jet hard finishing for temperature stability and tool life
  • Selective groove & thread masking during hardening to prevent brittleness
  • Oil flow, bearing fit and gear clearance tolerancing