Honing Vs Boring of Cylinders: The difference

What is honing?

Honing is a process used to improve the surface of a cylinder or tube to achieve tight tolerances or specific fine surface finishes measured in Ra. Using special abrasives, honing is usually a finishing operation of many different metals that are used in Aerospace, Nuclear applications, Oil and Gas and Motorsport and Automotive industries. Cylinder liners used in the automotive industry may require a visible cross hatch pattern with the degree of that pattern dependant on the customers’ requirements. Other applications may require a mirror like finish with no visible patterns or marks.

Benefits of using a honing machine

- Achieves accurate straightness or roundness on a surface.

- A safe and precise method of honing metal.

- Successfully corrects any tapering or unevenness.

- Corrects 'bore polishing' whereby the cross-hatched pattern has been worn down.

What is boring?

Boring is another form of metalwork that essentially involves making a hole in a mechanical part. It usually involves removing a lot of material from inside the cylinder and is a process that is done before honing. Sometimes the term boring refers to making a hole that has already been pre-drilled larger. Boring is carried out when manufacturing engine cylinders, gun barrels and other machining parts.

Types of boring

1. Line boring

This is where the boring bar used to make the hole is supported at both ends, and it can only be used when there is already a small through-hole drilled. 

2. Back boring
This is the boring technique whereby an existing hole is only on one side (not a through-hole) and so in order to complete the process the hole must be bored on the 'back' of the cylinder.

How do boring and honing work together?

In most projects, boring will be executed to increase the size of a hole and then honing will follow, to resurface the cylinder's internal walls. The honing process provides the final adjustments and creates the required finishing pattern on the interior of tubing or cylinder bores.

Can you use the same machine or tools for boring and honing cylinders?

No, it is not advisable. Boring a cylinder is not something a honing machine should be used for. This is not what honing machines are designed for. It may technically be possible, however, it would be very time consuming and the result would not be reliable or professional.

We hope this has answered some of your questions. If you are looking for a used honing machine or a honing machine for sale, we can help. Contact us today to find out more.