Gun Drilling Services for Deep Holes and Precision Bores

Holes up to 60" Deep & Aspect Ratios Exceeding 100:1

Greno Industries delivers in-house gun drilling services for deep, ultra-straight holes with depth-to-diameter ratios exceeding 100:1. 

Most machine shops outsource deep-hole machining due to equipment costs and complexity, but we keep it 100% in-house at our Scotia, New York (USA) facility to guarantee exceptional accuracy, shorter lead times, and lower total costs.

Why Choose Greno for Deep Hole Machining?

Most machine shops outsource their deep hole drilling. That’s not the case at Greno, where deep hole gun drilling is one of our specialties. 

Consider these advantages when you’re comparing shops.‍ ‍

  • True In-House Control: No subcontractor delays or secondary shipping costs. Your part moves directly from our turning centers to our gun drills under one roof.

  • Vibration-Dampening Rigidity: Our DeHoff machines use ground steel box ways rather than standard linear guides, achieving superior straightness over long depths.

  • High-Pressure Coolant Delivery: Coolant is forced directly through the tool shank to flush chips continuously out of the V-shaped flute, preventing thermal tool deflection.

Plus, Greno offers a full suite of precision machining capabilities.

Gun Drill Machine Specifications

Greno operates dedicated DeHoff gun drilling machinery built on rigid, cast-iron box ways for superior vibration dampening. This ensures straighter bores, tighter tolerances, and excellent surface finishes on difficult-to-machine materials.

MachineMaximum DepthHole Diameter RangeAdvantages
DeHoff 60” GundrillUp to 60 inchesUp to 1.25″ diameterIdeal for deep through-holes, long shafts, and heavy turbine components.
DeHoff 24” Dual-Head GundrillUp to 24 inchesUp to 1.25″ diameterDual heads for high-efficiency, multi-axis, or high-volume custom production.

Metal Materials Drilled

We routinely machine tough, high-temperature superalloys, defense-grade metals, and hardened steels:

  • High-Temp Superalloys: Inconel 718, Titanium

  • Stainless Steels: 17-4 PH, 300 & 400 Series

  • Alloy & Carbon Steels: 4140, 4340, Tool Steels

Deep Hole Gun Drilling Applications

Greno’s deep-hole drilling is vertically integrated with our CNC milling and large-diameter turning centers, providing single-source manufacturing for mission-critical components:

  • Large Industrial Fasteners: Precision axial through-holes for custom heavy-duty studs, bolts, nuts, and threaded components used in severe-service environments.

  • Power Generation & Steam Turbines: Deep cooling channels, lubrication paths, and turbine shaft lines utilizing Inconel and specialized alloys.

  • Hydraulics & Pneumatics: Ultra-straight, smooth-finish cylinder bores, manifolds, and high-pressure valve blocks ensuring reliable long-term sealing.

  • Defense & Aerospace: Rigid, high-tolerance components requiring ITAR-compliant, high-precision machining from start to finish.

custom fasteners | aerospace fasteners | carbon steel fasteners | inconel fasteners | military fasteners

Gun Drilling vs. Trepanning vs. Boring

Gun drilling is the best choice for machined metal parts that require a high degree of precision. 

Machining MethodHow It WorksBest Used For
Gun DrillingUses a self-guiding, single-flute tool with high-pressure internal coolant to drill deep holes from solid stock.High-precision, small-to-medium diameter holes with extreme depth-to-diameter ratios.
TrepanningCuts an annular groove around a solid center core instead of converting the entire hole into chips.Large-diameter deep holes where core material recovery is cost-effective.
BoringA secondary single-point tool operation that expands and refines an existing hole.Correcting concentricity, size, and finish of a pre-existing bore.

Get Started With Greno Industries