On-site taper grinding & spindle restoration
Restore spindle accuracy and toolholding performance without removing the spindle. Centerline now offers on-site machine tool taper grinding for CAT/BT and various other tapers — and, in many cases, BIG-PLUS and HSK. Reduce runout, improve efficiency, and extend the life of your machinery, with an average on-site grind time of 5 hours or less.
CAT · BT · HSK · BIG-PLUS · On-site in 5 hrs or less
The cause and effects of bad tapers
Over time, tool changes, crashes, and wear degrade the precision geometry of a spindle taper. The result is poor toolholding, increased runout, chatter, and declining surface finish — problems that compound across every part you cut.
On-site taper grinding corrects the taper in place, restoring the contact geometry to specification. That means tighter runout, better finish, longer tool life, and less scrap — without the downtime of pulling and shipping the spindle.
Common causes of premature taper wear
Tool-changer misalignment
Misalignment causes tapers to wear prematurely and unevenly, degrading contact across the toolholder.
Worn or dirty tools
Worn or dirty tools create high spots or gouging in the taper, leading to poor finishes and inconsistent holding.
Bell-mouthing & bad contact
Worn tapers with poor contact or bell-mouthing lead to chatter, poor finish, and shortened tool life.
We grind the taper in place — and prove it
We inspect the spindle pre-grind to assure it is in good operating shape, grind the taper on your machine, and finish with a full post-grind inspection so you know exactly what you are getting back. Average on-site time is 5 hours or less.
That means real cost and time savings compared with pulling the spindle and shipping it out for grinding or repair — and far less machine downtime.
Full post-grind inspection
- Tool gap — Verifies proper toolholder seating depth in the taper.
- Contact — Confirms full, even taper contact across the gauge.
- Runout — Measures restored concentricity to specification.
- Draw force — Checks retention force for reliable toolholding.
Reduce Runout
Restore concentricity and repeatable toolholding to specification.
Improve Efficiency
Better surface finish and tool life mean less rework and scrap.
Extend Machine Life
Regular taper maintenance protects your spindle investment.
Taper grinding questions, answered
- What is taper grinding and why does it matter?
- Taper grinding restores the precision geometry of a machine tool spindle taper. A worn or damaged taper causes poor toolholding, increased runout, chatter, and reduced surface finish. Regrinding the taper back to spec restores accuracy and tool life.
- Which taper types do you grind?
- Centerline grinds CAT, BT, HSK, and BIG-PLUS tapers, among others. On-site service means the taper is ground in place on your machine, avoiding removal and shipping.
- Do you inspect before and after grinding?
- Yes. We inspect the spindle pre-grind to confirm it is in good operating shape, then provide a full post-grind inspection including tool gap, contact, runout, and draw force.
- How long does on-site taper grinding take?
- Average on-site grinding time is 5 hours or less, so the machine is back in production the same day — far faster than pulling the spindle and shipping it out for grinding or repair.
- What are the signs of a bad taper?
- Common symptoms include tool marking or fretting, poor surface finish, increased runout, chatter, tool pull-out, and inconsistent toolholding. These often indicate the spindle taper needs regrinding.
Request an on-site taper grinding estimate
Talk to our spindle specialists about repair, taper grinding, or a custom build. Fast turnaround, guaranteed performance.