Splines and Splined Shafts


Carnes-Miller Gear can hob/shape external splines on blanks and shafts or shape/broach internal splines in gears or other cylinders.

Our larger shafts are 5in/127mm in diameter by 40in/1000mm length.


Involute Splines

To assure that a spline achieves a proper fit, we request that gaging be included in the budget presented to us. We also recommend full complement gaging for involute splines, especially in difficult to reach splines and harder grades of material. The alternative requires measurement between wires, which frequently is impractical.

For small lot quantities and reverse-engineering solutions where gaging may not be practical, the mating part, either male or female, can be used as the standard. Otherwise, we would have to consider making both parts, or else researching and developing different possibilities.

Straight-Sided Splines
Internal Splines
Internal straight-sided splines may require manufacturing either by broaching or by shaping.

Broaching is generally the best solution, depending on the quantity and length/size of spline.

Shaping can be more costly since it normally requires fabrication of a special cutter, or a single cutter to feed and index each slot.

External Splines
External straight-sided splines require a specially designed hob in order to produce the proper key and root width.

Carnes-Miller Gear generally has the tooling needed in our inventory. We recommend gaging or mating part verification to insure proper fit.