During the manufacturing process for many metals, surface imperfections may be expected or commonplace. This often isn’t much of an issue for some projects, but in those that require more precision in their finishing, a few additional processes may be used to remove these imperfections — and two of the most well-known such processes here are known as honing and lapping.

At Wasatch Steel, we’re happy to offer a wide catalog of steel products and services for clients throughout Salt Lake City and other parts of Utah, and we’ll assist you with any of your needs in this area. What are the lapping and honing processes within the metal world, how do they compare, and which might be right for your needs? Let’s go over everything you need to know.

Honing

The honing process, one that’s used both in metal and certain other production formats, refers to the process of removing metal from the inner surface of tube, pipes, holes or bores made from metal. This is done using a rotating abrasive stone, one that’s set to a precise diameter that’s only slightly smaller than the desired finished product. This stone is then slowly inserted into the workpiece, and it rotates in order to both clean and smooth out the surface. Honing can also be used in order to create a new, enlarged opening within an existing workpiece.

This process is often used in order to ensure that two products or materials will fit together snugly, and it’s also sometimes used in the creation of hydraulic cylinders. Honing is a popular choice for many because it tends to result in a much smoother surface than other methods, one that’s more resistant to wear and tear as well.

Lapping

The process of lapping, on the other hand, involves removing metal from the surface of the material itself. This is done through abrasive suspension, which refers to the process of grinding down the surface until it’s smooth. Lapping is often used in order to create a very high level of finish on the surface of the material, and it can also be used to improve the flatness or overall thickness tolerance.

Lapping is usually done by hand, though some machines are available that can help with this process. Generally speaking, there are two formats for lapping seen today:

• Flat lapping: Correcting surface irregularities in flatter products and surfaces.
• Doomed or ring: Correcting irregularities in rounded or other shaped products that are not flat.

During lapping, the material will be passed through flat lap plates, which are surrounded by a special liquid. This liquid contains a suspension of abrasive particles, which create friction and help to grind down the surface of the material. Lapping is a much slower process than honing, but it can create a much higher level of finish.

Honing vs. Lapping

So, how do these two processes compare? Here are a few key points to consider:

• Lapping is gentler: Generally speaking, lapping is known as a much “gentler” process than honing. This is because it’s removing metal from the surface of the product, rather than from the inside of it. Because of this, lapping is often considered a good choice for products that can’t handle too much wear and tear.
• Part locations: As the descriptions we went over above explained, honing is often used on parts that are located inside of the workpiece, while lapping is more often used for surface irregularities.
• Tight tolerances: Lapping can create extremely tight tolerances, much tighter than those created through honing. However, this process is also much slower, so it may not be ideal for all projects.
• Speed: Lapping is also significantly faster than honing in most cases, and this is because lapping does not produce any burrs or warp parts. However, there are some situations where a slower process is actually desired here — honing creates very little heat and pressure, meaning manufacturers retain control over important themes like hole size and part geometry.
• Both done near the end: One area where these two processes are very similar is where they fall on the timeline of manufacturing. Generally speaking, both of these processes are done near the end, after the product has been heat-treated and machined. This is because they’re designed to create a high level of finish, one that’s very smooth and precise.
• Involvement: Honing is considered the more “involved” process here, and as such is typically applied to products that have a greater quantity of surface imperfections. For instance, while both processes can be used to improve the surface finish of a product, lapping is more often used for products that require an extremely high level of finish — while honing may be used for products with a lower tolerance.
• Cost: In terms of cost, these two processes are very similar. They’re both considered to be relatively affordable, and the cost will depend on the size and scope of the project.

Both honing and lapping are important processes in the metal manufacturing industry, and each has its own advantages and disadvantages. In general, honing is considered to be more “aggressive” than lapping, while lapping is more gentle. Honing is often used for products that have surface irregularities, while lapping is more often used to correct flatness or thickness tolerances. Lapping can create very tight tolerances, but the process is slower than honing. In terms of cost, these two processes are very similar.

For more on the honing and lapping processes in the world of metal and steel, or to learn about any of our steel products or services to SLC clients, speak to the team at Wasatch Steel today.