Lapping is a precision process or combination of processes used to provide flatness, parallelism, size, and surface finishes to extremely demanding tolerances.

The process is a manufacturing method that employs particles of abrasive material to remove stock from a surface. It is comparable to sanding or grinding, except that sanding and grinding use abrasives that are fixed (bonded abrasives) whereas lapping employs abrasives that are suspended in a liquid carrier, and are free to move about. Lapping is sometimes referred to as ‘Free Abrasive Machining’.

Lapping is a process used where the surface finish, flatness, or parallelism of the workpiece must be held to very close tolerances. Lapping can achieve a flatness rating of 6 millionths of an inch (0.000006″), parallelism tolerances of ten-millionths of an inch (.00001″), and surface finishes to 0.6Ra. using special handling and tooling techniques.

We can achieve flatness tolerances of 12 millionths (0.000012″), the parallelism of fifty millionths (0.00005″), and the flatness of 6 Ra on a volume production basis. 

We can achieve tolerances at the limits of the lapping process (down to one-millionth of an inch) on a case-by-case basis.

Utilizing our specialized equipment and proprietary processes, we can produce flat and parallel surfaces from thousandths to millionths of an inch, in production quantities, at an economical cost.



Single-Sided Lapping

Single-Sided high-speed lapping allows a competitive alternative to grinding with better-finished part quality.
Some applications that are ideally suited to our lapping processes include:

  • First surface referencing for subsequent operations
  • Small, thin, or “hard to hold” pieces
  • Fuel injector components
  • Any sealing face/surface
  • Gear and rotary pumps
  • Slitter knives and spacers
  • Valve plates and bodies
  • Ceramic, glass, powdered metal, metal injection molding, carbide, titanium, molybdenum, stainless steel, Inconel, and other hard to machine materials.
  • Hard coat anodized surfaces
  • Extrusion, CNC, and screw machine “cut off” sizing

Double-Sided Lapping

Double-Sided Machining is the most desirable choice when processing is required on both sides of a part, or when there is a need for precise thickness, parallelism or flatness on both sides of the part.
Some of our typical applications would include:

  • Precision Computer Components
  • Gage Blocks
  • Precision Spacers
  • Slitter Knives and Spacers
  • Thin, Brittle Materials
  • Bimetal Pump Swash / Wear Plates
  • Cutting Inserts
  • Precision Piston Rings
  • Automotive Sensing Devices
  • Hydraulic Gear Pump Components