Axial Feed Unit: Do’s & Don’ts

August 14, 2025

Preventive maintenance is one of the most effective ways to extend the lifespan of your axial feed unit (AFU) and keep your line boring machine running at peak efficiency. While each customer’s routine will vary depending on usage and care, one rule holds true: the better you treat your AFU, the better your overall machining results will be.

If the unit is kept clean, dry, handled gently, and stored properly, it often requires little maintenance — each AFU is internally greased and precision-adjusted during construction or refurbishment. Heavy daily use, however, will wear components faster, typically requiring a full refurbishment every 2–3 years. Light-use units may last 4–6 years before servicing is needed. Most repairs we see at CLIMAX are simply the result of components reaching the end of their service life.

By following the do’s and don’ts below, you can maximize uptime, protect your investment, and keep your AFU running strong for years to come.

✔ DO: Keep it clean

After each use, remove chips from machining inside the AFU bore. Leftover debris can bind the unit on the bar or damage the bar during the next installation.

✔ DO: Alternate sides during cuts

Your AFU has two feed arms with clutch bearings. Switching sides when feeding spreads wear evenly across both sets of bearings and the lead nut, extending use between refurbishments.

✔ DO: Tighten both clamp collars before a cut

This ensures stability, precision, and protection for the feed mechanism during operation.

✘ DON’T: Strike the Unit with a Metal Hammer

Using a hammer to install, remove, or shift the feed adjust into neutral can damage the housing, collet, or feed components.

✘ DON’T: Adjust Factory-Set Feed Stops

The two ¼″ internal hex set screws control minimum and maximum feed. Altering them can cause erratic feed or permanent damage.

✘ DON’T: Clamp When Not on a Bar

Tightening clamp collars without a bar in place can deform the collet, leading to unnecessary replacement costs.

Protect Your Investment

Small, consistent care steps dramatically extend your AFU’s service life and ensure optimal performance. Contact CLIMAX today for expert guidance tailored to your usage and application — and to learn how proper maintenance of your axial feed unit can also boost the performance and longevity of your entire line boring machine.