All machines from the category Lapping

How a lapping machine works

A lapping machine is a machine tool for precision machining of metallic and non-metallic surfaces. Lapping is a cutting process with an indefinite cutting edge, similar to grinding, honing, or polishing, and is primarily used to correct very small dimensional deviations, achieve the highest possible flatness, and produce extremely smooth surfaces.

During lapping, a lapping agent is applied between the workpiece and a so-called lapping wheel – usually a mixture of abrasive grain (e.g., corundum, silicon carbide, or diamond) and a carrier fluid (e.g., oil or water). The lapping wheel is made of cast iron, steel, or a special material mixture and is driven at a constant speed. The pressure and relative movement between the lapping wheel and the workpiece result in micro-fine material removal. Depending on the type of machine, the workpiece can be moved in a rotating, oscillating, or linear motion, ensuring uniform machining.

Lapping machines are used in precision engineering, optics manufacturing, medical technology, the semiconductor industry, and toolmaking—anywhere where the highest possible flatness, dimensional accuracy, and surface quality are required.

Surface quality during lapping

The process is characterized by a highly controlled and grain-bound removal rate, which allows dimensional tolerances in the micrometer range to be maintained. Lapping can achieve an extremely fine surface finish. Typically, a roughness of Ra 0.01 to 0.1 µm is achieved, depending on the material, lapping agent, and process parameters. In specialized applications, values below Ra 0.005 µm are even possible – ideal for optical components, high-precision guides, or sealing surfaces in vacuum technology.

Types of lapping machines

There are single-disc and double-disc lapping machines. With a single-disc lapping machine, the workpiece is only processed on one side. With a two-disc lapping machine, it is processed on both sides simultaneously between two lapping discs. Modern CNC-controlled models allow for automated process control, which ensures consistent quality, especially in series production.

Structure of a lapping machine

A lapping machine essentially consists of the rotating lapping disc as the central processing element. In addition, there are workpiece carriers or holding devices that position the workpiece precisely. A drive system ensures the rotation or oscillation of the lapping disc and, if necessary, also of the workpiece carriers. A dosing system for lapping and cooling agents is used to supply the abrasive. A machine frame ensures stability and precision. Modern lapping machines also have a control unit for process control, often CNC-based. Double-sided lapping machines have two integrated lapping discs – one upper and one lower – between which the workpiece is processed.

Applications in industrial manufacturing

Lapping machines are in demand wherever extreme precision and surface quality are required. Typical industries of application are precision engineering, the optics industry, the automotive industry, semiconductor technology, medical technology, mechanical engineering, and tool and mold making. Aerospace technology and the watch industry also benefit from the fine material removal achieved by lapping.

Typical workpieces that are processed on lapping machines are:

• Dressing rings
• Sealing surfaces of valves
• Flatness test specimens
• Injection nozzles
• Threads
• Hard metal inserts
• Ceramic substrates
• Piston plates
• Crankshafts
• Bearing plates
• Camshafts
• Optical lens blanks
• Precision guides
• Valves
• Valve seats
• Gears
• Silicon wafers
• Shafts
• Dental instruments
• Gears
• Cylinder head

Lapping is often the only solution, especially for flat components that need to be machined to be plane-parallel and distortion-free.

Advantages and disadvantages of lapping

Lapping offers very high precision with equally high dimensional accuracy, flatness, and surface quality—ideal for sealing surfaces and optical applications. It is suitable for almost all materials and enables micrometer-precise removal without thermal stress.

Disadvantages include the comparatively low material removal rate, the high time requirement, and the need for special lapping agents and cleaning processes. In addition, the process is difficult to automate and requires experience to ensure consistent results with complex geometries.

Ultrasonic lapping

Ultrasonic lapping combines classic lapping with high-frequency vibrations. The tool or lapping wheel is excited by ultrasonic vibrations, which makes the lapping agent more effective. This results in faster material removal, improved surface quality, and lower thermal stress—particularly advantageous for hard or brittle materials such as ceramics or glass.

What is the difference between honing and lapping?

Lapping and honing are precision machining processes, but they differ in their application and tools. Lapping is performed with loose grit between the workpiece and the lapping wheel, producing flat, highly precise surfaces. Honing uses firmly bonded grinding stones, usually works on cylindrical inner surfaces, and produces defined cross-hatch structures for optimum lubrication.

What is the difference between lapping and grinding?

Grinding uses rotating tools with firmly bonded abrasive grains to remove material quickly – often for shaping and dimensional machining. Lapping, on the other hand, is a slower precision machining process with loose grain that achieves maximum flatness and surface quality, usually without significant shape intervention.

What is the difference between lapping and polishing?

Lapping is a cutting process using loose abrasive grain to produce extremely flat and dimensionally accurate surfaces. Polishing, on the other hand, is usually a non-cutting process that uses very fine abrasives or pastes to smooth and polish surfaces – without targeted material removal.

Tools for a lapping machine

Specific tools are used in lapping machines:

• Lapping discs made of cast iron, steel, glass, or ceramic materials, depending on the material and the desired machining quality.
• Abrasive grains such as corundum, silicon carbide, boron carbide, or diamond are used as lapping agents in combination with carrier fluids such as oil, water, or emulsions.
• In addition, workpiece holders or retaining rings are used to securely fix the components in place.
• In double-sided machines, planetary carriers ensure uniform movement.
• Cleaning devices and dosing systems for uniform lapping agent supply are also part of the range of tools.

Accessories and operating materials for a lapping machine

Of central importance is the lapping agent (consisting of abrasive grain and carrier fluid), which must be refilled and adjusted regularly. Cleaning equipment for lapping discs and workpieces, collection containers for used suspensions, and filter systems for treating the lapping agent are also required. Accessories such as measuring equipment for flatness testing, workpiece carriers in various designs, and, if necessary, protective devices for ergonomics and occupational safety complete the equipment. CNC-controlled models also require software updates and interface modules for process integration.

Leading manufacturers of lapping machines

Our manufacturers directory includes companies that produce lapping machines for metalworking.

The following terms are frequently searched for: EFCO lapping machine, Engis lapping machine, FLP lapping machine, Gehring lapping machine, Gleason lapping machine, Joke lapping machine, Kemet lapping machine, LAM PLAN lapping machine, Lapmaster Wolters lapping machine, Okamoto lapping machine, PSS lapping machine, Stähli lapping machine, Sunnen lapping machine

Selecting the right lapping machine

If you want to buy a lapping machine, there are several important features and specifications to consider.

• First, the size of the lapping wheel should match the workpiece format and the planned number of pieces.
• The adjustment options for contact pressure, speed, and running time also influence precision and repeat accuracy.
• It is also important to consider whether the machine is single-sided or double-sided – the latter are more efficient for high quantities and symmetrical components.
• Other relevant specifications include the material compatibility of the lapping discs, the dosing accuracy of the lapping agent, and the control and automation options.
• In series production, machines with integrated process monitoring and data logging are particularly advantageous.
• Maintenance requirements, the availability of spare parts, and technical support from the manufacturer should also be taken into account when making a purchase.
• Last but not least, energy efficiency and compatibility with existing production facilities play a role in the investment decision.

Search now at maschinenauswahl.de for the lapping machine that suits your production requirements.

Information about lapping and lapping machines

This article answers the following questions, among others, and helps with the search terms mentioned:

• What is lapping?
• What does lapping mean?
• Lapping explained simply
• Lapping manufacturing process
• Lapping vs. honing
• Lapping vs. polishing
• Advantages of lapping
• Disadvantages of lapping
• Lapping dressing rings
• Lapping injection nozzles
• Lapping threads
• Lapping crankshafts
• Lapping dressing rings
• Lapping application examples
• Lapping camshafts
• Lapping valves
• Lapping gear teeth
• Lapping gears
• Lapping cylinder heads
• Lapping wafers