Gun Drilling Services at Greno Industries

Greno Industries provides gun drilling services for long, straight, precision-machined holes. Most machine shops outsource this work, but we keep it in-house for exceptional accuracy and repeatability. If you found us by searching for “gun drilling services near me”, don’t hesitate to contact us – even if you’re not next door to our Schenectady, New York facility.

With decades of experience serving customers in markets like power generation, oil and gas, aerospace, defense, and heavy equipment Greno is a trusted deep-hole specialist. Whether you need a 60-inch through-hole in Inconel 718 or precision drilling for large custom fasteners, we have the tools, equipment and technical expertise to meet tough requirements.  

What Is Gun Drilling (Gundrilling)?

Gun drilling, or gundrilling, is a deep‑hole drilling process that uses a self‑guiding, single‑flute cutting tool to produce straight, accurate holes at extreme depth‑to‑diameter ratios. Unlike conventional drills, a gun drill incorporates the following features:

• A self‑piloting tip that maintains straightness

• A long, stiff shank that resists deflection

• High‑pressure coolant delivered through the tool to evacuate chips and control heat

This combination allows Greno to achieve hole depths that are greater than 100 times the diameter while maintaining tight tolerances and excellent surface finishes. When parts need deep bores, lubrication channels, or precision through-holes that standard drilling can’t achieve, ask us about gun drilling. 

It’s a different process than trepanning or boring. 

Deep Hole Drilling: Gun Drilling vs. Trepanning

Gun drilling and trepanning are both deep-hole drilling techniques, but they differ in terms of efficiency and material usage. Gun drilling is typically used for small-diameter, high-precision holes. The entire core is converted into small chips. By contract, trepanning cuts only an annular groove, leaving a solid center core that can be removed and reused.

Gun Drilling vs. Boring

Gun drilling is a high-pressure, single-flute process designed to create deep, straight, and precise holes from solid material, often with depth-to-diameter ratios beyond 100:1. By contrast, boring is a secondary, single-point tool operation that enlarges, refines, and improves the accuracy of an existing hole.

Greno’s Gun Drilling Capabilities

At Greno Industries, gun drilling is a core competency, just like our 3 axis and 4 axis milling and large diameter turning services. As specialists in precision machining, we can produce deep drilled holes that other shops can’t match. The stability and rigidity that our equipment provides is essential for deep-hole accuracy. 

We operate two dedicated gun drilling machines at our Made in USA manufacturing facility:     

• DeHoff 60” Gundrill

• DeHoff 24” Dual‑Head Gundrill

Both machines feature:

• Cast iron drill head bases

• Hardened and ground steel box ways

• Precision‑fitted mating components

Compared to linear guideways and milled surfaces, this design provides superior vibration dampening. The means longer tool life for us and these important benefits for our customers:  

• Better hole straightness

• Improved surface finish

• More consistent tolerances

Gundrill Performance and Material Capabilities

Greno’s gun drilling equipment is engineered for demanding applications, including:

• 1.25” through‑holes up to 60 inches deep

• High‑pressure coolant delivery for efficient chip evacuation

• Precision tolerances maintained throughout the entire bore

• Difficult‑to‑machine materials, including high‑temperature superalloys

We routinely drill materials such as:

• Inconel 718

• 17‑4 PH stainless

• 4140/4340 alloy steel

• Carbon steels

• Stainless steels

• Tool steels

Why In‑House Gun Drilling Matters

Most shops outsource their gun drilling services because the equipment is expensive, the process is technically demanding, and the learning curve is steep. Greno takes the opposite approach. We’ve brought this capability in‑house to give our customers:

• Shorter lead times

• Better quality control

• Lower total cost

• Fewer subcontractor delays

• Tighter integration with our turning and milling operations

This vertical integration is especially valuable if you need both deep‑hole drilling and large‑diameter turning. By combining our gun drilling capabilities with our horizontal CNC lathes, we’ve become one of the region’s leading manufacturers of large industrial fasteners.

Examples of these products include:

• Studs

• Nuts

• Bolts

• Custom threaded components

Greno is also a leader in steam turbine parts manufacturing.

Gun Drilling Applications

Gun drilling is essential for parts that require long, straight, accurate bores. Industries and applications include:

• Large Industrial Fasteners: Deep-hole drilling is used to drill precise, long-axis holes in solid metal bars for weight reduction, coolant circulation, or assembly.

• Hydraulic and Pneumatic Components: Cylinders, manifolds, and valve bodies often require deep, precision bores that must maintain straightness and surface finish to ensure proper sealing and performance.

• Energy and Power Generation: Turbine components, pump shafts, and high‑pressure system parts frequently require deep‑hole drilling in high‑temperature alloys.

• Defense and Military Machining: Gun drilling originated in the firearms industry, but today it’s used for a wide range of defense components requiring precision bores.

• Industrial Manufacturing: Rolls, shafts, and tooling components often require deep bores for cooling, lubrication, or weight reduction.

Precision Machining from Start to Finish

Gun drilling at Greno is engineered for accuracy, consistency, and repeatability. Our process includes the following steps: 

1. Engineering Review: We evaluate your drawings, tolerances, materials, and functional requirements to determine the optimal drilling strategy.

2. Fixturing and Setup: Rigid fixturing is essential for deep‑hole accuracy. Our machines are designed to minimize vibration and maintain alignment throughout the drilling cycle.

3. High‑Pressure Coolant Delivery: Coolant is pumped through the gun drill’s shank directly to the cutting edge, flushing chips out through the V‑shaped flute. This prevents heat buildup and ensures a clean, stable cut.

4. Real‑Time Monitoring: Operators monitor feed rate, pressure, chip evacuation, and tool wear to maintain consistent performance.

5. Inspection and Verification: We verify hole straightness, diameter, and surface finish using precision metrology tools. If required, we can provide inspection documentation for quality assurance.

Why Choose Greno for Gun Drilling Services?

If you’re searching for Carlson deep hole drilling, Nelson precision drilling, or gun drilling services from local competitors, choose Greno for these important advantages.  

• Deep Expertise: Our machinists are trained specifically in deep‑hole drilling techniques, giving us a level of expertise that general machine shops cannot match.

• Superior Equipment: DeHoff machines are widely recognized as industry leaders in deep‑hole drilling. Their rigidity and precision allow us to achieve exceptional results.

• In‑House Integration: Because we combine gun drilling with large‑diameter turning, milling, and CNC machining, we can complete complex projects under one roof.

• Experience with Difficult Materials: From Inconel to hardened steels, we routinely drill materials that challenge other shops.

• Trusted by Industry Leaders: Manufacturers across energy, defense, heavy equipment, and industrial manufacturing rely on Greno for mission‑critical components.

Request a Quote for Gun Drilling Services

If your project requires deep, accurate, precision‑machined holes, Greno Industries is ready to help. Our in‑house gun drilling capabilities, combined with our large‑diameter turning and CNC machining services, make us one of the region’s most capable deep‑hole specialists.

Contact us to discuss your application or request a quote.