Expanding Small Shop Capabilities with Single-Point CNC Broaching

Adding keyways and splines without adding dedicated broaching equipment

For a small machine shop, adding new manufacturing capabilities often means investing in more equipment, finding additional floor space, or outsourcing work to a specialty shop. Single-point CNC broaching offers another option.

With the proper tooling, setup, and programming, shops can produce keyways and splines using CNC lathes and mills already on the floor. This gives smaller operations an opportunity to take on more complete parts while maintaining control over the manufacturing process.

Adding Capability to Existing CNC Equipment

Traditional broaching may require a dedicated broaching machine, press, or secondary operation. For a small shop, purchasing another machine may be difficult to justify when broaching represents only one portion of the overall workload.

Single-point CNC broaching uses the linear movement of a CNC lathe or mill to produce the feature incrementally. A broaching insert removes a small amount of material with each stroke until the required keyway or spline geometry is achieved.

This allows shops to add broaching capability without dedicating additional floor space to another machine.

Keeping More Operations In House

When a shop cannot produce a particular feature, that portion of the job usually has to be outsourced. Internal keyways and splines are common examples because they are often associated with specialized broaching equipment.

Outsourcing adds another step to production. Parts must be packaged, shipped, scheduled with another supplier, returned, and inspected before the job can continue.

Bringing suitable broaching operations in house can help reduce:

• Outside processing costs
• Shipping and handling
• Part movement between suppliers
• Scheduling dependencies
• Lead times associated with secondary operations

For a small shop managing multiple jobs and limited machine capacity, having greater control over the production schedule can be especially valuable.

Taking On More Complete Parts

Adding CNC broaching capability can also change the types of jobs a shop is able to quote.

Instead of turning down a part because it includes an internal keyway or spline, the shop can evaluate whether the feature can be produced on its existing CNC equipment. This makes it possible to perform more of the manufacturing process under one roof.

The benefit is not simply adding another machining operation. Each new process a shop learns builds internal knowledge. Machinists gain experience with broaching setup, alignment, insert selection, and programming that can then be applied to future work.

Over time, that experience can expand the range of parts the shop is comfortable quoting and producing.

Getting the Setup Right

Single-point CNC broaching still requires the same attention to setup and programming as any other precision machining process.

Rigidity, proper centerline alignment, limited tool overhang, and secure toolholding all contribute to a stable broaching operation. The insert should also have adequate entry and exit clearance, and the program should maintain controlled linear motion throughout the cutting stroke.

For blind keyways, the part must provide a suitable relief groove or cross hole so the insert can clear the feature before retracting.

Understanding these requirements before accepting a job helps determine whether CNC broaching is appropriate for the application.

More Capability Without Another Machine

Small shops do not always need another piece of equipment to expand what they can manufacture. Sometimes the opportunity is finding new ways to use the machines they already have.

Single-point CNC broaching allows suitable keyways and splines to be incorporated into existing CNC workflows. For shops looking to reduce outsourcing, take on more complete parts, and build additional machining knowledge, it can be a practical way to expand capability without expanding the shop floor.