When we want to transfer rotary motion from one point to another in any device, we commonly rely on a spline connection.

A spline connection includes a spline shaft mate with gear or another rotary device. The teeth can be straight, serrations (angle form), or involute shape as shown below.

The Type of Splines

Parallel Key Splines:

The equally spaced teeth are straight-sided. This spline type is similar to a keyway drive, but there are many keys equally spaced around the circumference.

Involute Splines:

Involute splines have a more smooth transition than parallel key splines. It is by a radius that lowers stress concentration and fatigue cracking during operation.

Crowned Splines:

The purpose is to allow angular misalignment during operation. The female spline (as we made by the broaching machine) is usually not crowned.

Serrations:

The teeth form is neither straight nor involute. It is in the form of an included angle. This design is mainly used in smaller diameter drives as more teeth can be used on a small circumference.

Helical Splines:

They can be either straight or involute. The helix help distributes the rotational torque along a greater length of the shaft. They can also be applied in transfer motion across and around the shaft itself.

The Comparison between the Spline Broaching and the Keyway Broaching

Fatigue life: Spline > Keyway

The spline connection has a longer fatigue life than a keyway drive because it equally distributed load along the sides of the teeth.

Manufacturing cost: Spline broaching > Keyway broaching

It requires more complex technology to make a spline, including broaching tools, fixtures, broaching machines, etc. For example, when the precision requirement of the spline is high, many customers choose our well-designed broaching tools with servo-driven broaching machines to make.

Learn more about AXISCO spline broaching tool: Broach cutting tool & Spline broaching tool

Manufacturing time: It depends

Whether it is a spline or a keyway, the deeper a spline or a keyway is, the more cuts it requires. The manufacturing time depends on how long the tool is and how many cuts it requires to finish a workpiece.

The Spline Broaching Examples from Axisco

Good broaching machines, tools, and fixtures are essential for the success of spline broaching. Axisco is your best partner to support with a turnkey solution.

More: How surface broaching works? The benefits of surface broaching