Complex Boring

Step Boring

Boring is the process of enlarging holes that have already been drilled, ensuring they are concentric and properly sized and finished post manufacturing. However, when working with intricately machined parts and costly, difficult to drill metals and alloys, boring becomes far more complex than the simple drilling of a hole.

Based on our proven track record with deep hole drilling of seamless precision tubing, Confluent Maine has expanded its gundrilling capabilities to support our customer’s varied engineering and manufacturing needs. We offer pattern drilling and step boring services performed with the same attention to  quality control and industry leading tolerances to complement our gundrilling services.

Confluent Maine offers a variety of complex boring services, including: step boring, blind bottom boring, chamfering and complex pattern drilling. If your machined part or tubular component requires pattern drilling or another complex boring service, please contact one of our engineering consultants to see how our capabilities fit your project’s unique design and manufacturing requirements.


Blind Bottom Boring: A blind bottom bore is a hole with a bottom or surface that doesn’t allow the drill or tool to go all the way through the part or component being drilled. Blind bottom bores require experienced machinists and state-of-the-art equipment. Tools must be carefully maintained and controlled in order to achieve blind bottom bores with tight tolerances and finishes. Blind bottom bores can have flat or flush bottoms (no relief), or round or tapered edges (with relief, shouldered holes). Precision blind bottom boring requires modification of standard tooling procedures, extensive knowledge of how different metals and alloys behave during boring and a commitment to accuracy. Confluent Maine performs blind bottom bores with confidence born of experience.


Step Boring: Step boring is a specialty precision boring process containing more than one diameter and/or additional features, such as finishes, chamfers, etc. Step boring tools have inserts which are set at different heights and diameters, allowing machinists to enlarge existing bores or add features, all while bringing holes within precise finish limits and tolerances. Plans may call for step bores when components, such as screws and bolts, need to be countersunk or lie flush with the surface of a part. Confluent Maine has the resources to provide stepped bores with the same accuracy and precision we offer in our precision, deep hole (borecentric) boring process.

Chamfering: Confluent Maine precision machines chamfers (beveled edges) in a variety of metals and metal alloys. While chamfers are usually cut at 45 degree angles, Confluent Maine also has the ability to round or taper edges, and machine at transition points.

Pattern Drilling: Pattern drilling involves removing material from a part in a sequence of machined holes, often in a variety of sizes, depths and physical orientations. Using state-of-the-art cutting machines in a carefully controlled manufacturing facility, Confluent Maine’s machinists have experience pattern drilling a wide variety of metals and metal alloys. Variations in angle, hole depth and shape make these projects difficult, if not impossible, for many machine shops. Confluent Maine handles these complex challenges with confidence, knowing every part and material requires a unique approach. Our staff will ensure that your project is finished with precision, no matter how complex the pattern or design array.

If your project calls for complex machining in any of the above categories, please contact one of our experienced engineering consultants. Confluent Maine is proud to partner closely with customers in the medical, aerospace, energy and industrial sectors on tubular component and gundrilling projects which may involve complex machining. We are experienced in providing detailed bores with a variety of internal features in metals and exotic alloys including titanium, 17-4PH stainless steel, molybdenum and many others. We look forward to assisting you with your project, whether large or small.

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