lapping process

The Lapping Process: When Precision Is the Only Option

The lapping process is a specialized bore finishing procedure for those applications with extremely tight tolerances. It goes beyond the core capabilities of even the most advanced honing process to deliver cylindricity within 0.000060” (0.0015 mm); straightness within 0.000040” (0.0010 mm); and roundness within 0.000015” (0.0004 mm).

How Automated Lapping Works

At one time, the lapping process was a labor-intensive, manual procedure with a high margin for error. Today, Sunnen is the exclusive provider of automated bore lapping solutions. Sunnen’s patented machine uses a tool known as a lap, which resembles a honing mandrel but with grooves instead of abrasive stones. As the lap enters the bore it spreads a loose abrasive compound between the tool and the wall of the bore. As the tool rotates and reciprocates within the bore the abrasive compound removes excess material and creates a uniform surface finish. The machine periodically gauges the size of the bore and continues the lapping process until the bore is within specifications…all without operator intervention.

Automated Lapping Is Used To:

  • Improve consistency of finished parts
  • Reduce reliance on human operators
  • Reduce potential for repetitive motion injuries associated with manual lapping
  • Improve workplace safety by eliminating manual processing
  • Tighten tolerances in bore diameter, roundness and straightness

Typical bore lapping applications include:

  • Piston pumps and other aerospace parts
  • Hydraulic valves and sleeves
  • Thin-walled parts that are prone to distortion when honing
Find Your Application

Everything You Need. When You Need it.

In addition to our unique SVL-2115 machine, we offer a complete line of accessories to keep your lapping machine up and running for the long haul:

  • Tools
  • Abrasive compound
  • Filtration systems
  • Flushing fluids

We’re On Your Team

We stand by our work and support our customers. Sunnen is the only company in our industry to provide a standard three-year warranty on every machine we make. We also offer machine installation, service and preventative maintenance to keep your operations running smoothly and address any emerging manufacturing challenges.