Line Boring

Line boring, which can also be called align boring, is a term used to describe an engine machining process. The task involved here is to create perfectly straight and aligned bores. These are used for the camshaft housing, which is also known as the saddles and tunnels, as well as the crankshaft. When it comes to any of the steps in this process, line boring is perhaps the most essential step in the entire blueprinting process for an engine block.


The use of a line boring machine is very specific. It is designed to enlarge a hole that is already in place, usually from previous casting and drilling. This is one of the tools used to cut into the component. There are various cutting tools that can be used within the machine to create this outcome. These are done using a boring head. With the right tools, it is possible to create a very accurate and precise finished product. The hole diameter is enlarged, and there is ample accuracy.

The term line boring is thrown around in the machining industry often, but not everyone is familiar with this common practice. Line boring is necessary for several machining projects and repairs and can range from simple procedures to complex situations requiring months of work and the input of many engineers.

A line boring job often depends on the complexity of the machine, the number of bores and how damaged or worn a bore may be. Sometimes, simple repairs can be completed onsite in a few hours. However, there are many cases in which engineering layouts must be obtained, as well as custom boring bar systems. These larger projects can take multiple technicians and sometimes months to complete.

Line Boring Machine

A line boring machine is used for enlarging a hole that has already been drilled or cast, using one or more cutting tools held within a boring head. In doing so, the operation achieves greater accuracy of the hole diameter.

Line boring machines are used on a wide range of projects, with some common examples including:

In addition to machining parallel bores, line boring machines can also be used for tapering holes and for machining the outside face of the work piece using a facing head.