Machine Shop Deep Hole Drilling

Most machine shop clients are familiar with drilling services. Deep Hole Drilling that goes far deeper than the typical drill length requires special equipment to apply the work.

The major methods involved are Gun Drilling, BTA Drilling, and Ejector Deep Hole Drilling. Each one provides a specific type of drilling performance as well as advantages for machining. Which one is used depends on the tolerance limitations needed as well as the precision of the cavity.

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The Challenge

The first big challenge is the friction of the drilling. When metal drills on metal, the energy creates heat. Deep inside the cavity that is extended, that heat has nowhere to dissipate. So, another method of cooling versus just air alone is needed. Not addressing the need is a sure-fire way to end up cracking and fragmenting the drill head. Secondly, the drill process needs to get rid of its waste. Drill shavings are normally exited by the nature of the drill; the shape of the drill winds the shavings out of the cavity and ejects them. However, when dealing with a deep hole, that’s not possible, so another solution is needed for this challenge as well.

Modern machine shop deep hole drilling provides significant benefits by combining the solutions above. That produces a shorter drilling time duration, a significant cut back in machine setup time, and a reduction in final mold product delivery for customers as well. No surprise, combination deep hole drilling machines make a lot of sense as a result.

The Gun Drilling process produces a cavity that can range from 2.5mm to as much as 40mm. The drill bit has a coolant channel integrated within which negates the friction heat problem. The same coolant flow also lubricates and caries the chips out as well.


The Ejector approach provides a much bigger cavity capability with a range of 18 to 250 mm. It’s an improved approach over the BTA method. However, the Ejector approach provides a far better coolant application, and it still captures the debris and removes it from the working cavity effectively. Again, however, this method relies on a slower, lower-powered approach to the drilling power.

Finally, Gun Drilling for deep hole fabrication is a common modern approach for cavity ranges from 1 to 50 mm. Originally used for gun barrel drilling, ergo the name, it’s now a method used for highly accurate applications via modern machinery and drilling systems. It’s also still used for firearms. Given the detailed work possible, Gun Drilling is also used for medical devices, plastic injection mold finishing, fuel line fabrication and similar fine-tuned applications.

Deep hole drilling is ideal for machine shop automotive work. However, whatever deep hole method is applied, a machine shop for engines needs to have the right equipment for the work. If not, then it needs to have the benefit of deep hole services from a reliable vendor for the same. Acromatic Deep Hole Drilling can meet the need. Give us a call to find out more.

Contact us to discuss our aerospace and automotive drilling services. Acromatic Deep Hole Drilling looks forward to working with you!