When you’re assembling furniture, building a deck, or hanging a door, you’re dealing with tools, materials, and methods that are relatively forgiving. Being off by a millimeter or two won’t cause everything to fall apart. In industrial applications, however, tolerances need to be much more precise; even the slightest deviation in the smallest part can cause a cascade of problems or failures. Precision Mold & Machining Services relies on gun drilling to ensure exacting tolerances in challenging drilling situations.

What is Gun Drilling?

Gun drilling gets its name from its original purpose. Roughly a century ago, the gun drilling process was developed to manufacture straighter, and more accurate, gun barrels. As so often happens, other industries quickly found use for the technology. 

Uses & Applications For Gun Drilling

Gun drilling is commonly used in the production of plastic injection molds for drilling cooling lines or ejector pin holes. It’s equally useful in die making, engine components, and even a wide variety of medical equipment. While most frequently used where greater depth is required,  it also finds use in shallower applications, since a gun-drilled hole requires less finishing than other drilling methods; this can be a significant help when time is of the essence.

Benefits of Gun Drilling

In order to maintain uniform diameter and straightness, a drill needs to be designed for a proper ratio of diameter to depth. A conventional drill bit is effective at fewer than five diameters, so if you’re using a one-inch bit, you shouldn’t use that bit to drill deeper than five inches. The larger the ratio of depth to diameter, specialized equipment is needed, such as a peck drill or parabolic flute, which can handle up to 20 diameters.

But what do you do when you need a four-millimeter hole that needs a depth of 1,600 millimeters? A standard hand drill won’t be equal to the task. Gun drills can handle small-diameter holes (typically in the range of 1 to 50 millimeters) that require depths of 200 to 400 diameters. The necessary depth is achieved without losing the degree of precision required for hole diameter or straightness. 

The Gun Drilling Process

Due to the nature of gun drilling itself, holes can be drilled at high feed rates. This in turn keeps both costs and lead times down and keeps our customers satisfied. Not only do we offer gun drilling for the mold industry, but for applications across industries requiring deep holes with high precision and accuracy.

Our gun drilling equipment is kept good company by CNC tools like the DMU 85 monoBLOCK, a five-axis machine designed for smaller parts with tighter tolerances, and the DMU 210 P, which allows for large-envelope machining services. Our continuous investment in machinery and process improvements helps us deliver in volume, with unmatched quality.

Quality Assurance

Any company can promise high standards; we prove it through the processes in place for quality assurance, including AS9100D QMS and ISO 9001:2015 compliance. Our attention to detail ensures quality and products you can trust.

Gun Drilling Experts in Michigan: Get in Touch

When accuracy counts, the gun drilling services offered by Precision Mold & Machining Services cannot be equaled. Across a range of industries that includes aerospace, aviation, defense, medicine, and a number of others, we engineer solutions and products to the highest standards. We invite you to explore and take full advantage of our capabilities.


Precision Mold & Machining provides tight tolerance 3 and 5 axis machining of aerospace and automotive components, repairs and servicing of plastic injection molds, including CNC Gun Drilling, and EDM services. We offer our services to all industries including: automotive, aerospace, defense, consumer goods, and medical.

Contact Us

  • 13143 East 9 Mile Road Warren, MI 48089

  • Fax: (586) 774-2441

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