The smallest holes demand the deepest discipline.
Precision gun drilling from Ø2 to 40 mm, up to 6,000 mm deep — fuel-system bores, hydraulic galleries, sensor passages, and cooling channels where straightness and surface finish are functional requirements, not cosmetic ones. On a 7-axis CNC gun drill we designed and built ourselves.
A Ø3 mm drill, 2 meters long, has the slenderness of a raw spaghetti strand. It cuts steel anyway. Guiding, bushing support, and feed discipline decide whether it cuts straight or snaps.
Gun drills are single-flute tubes: high-pressure coolant travels through the tool body to the cutting edge and flushes chips back along the flute. Pressure, flow, and filtration are process parameters, not utilities.
At small diameters there is no boring pass to correct a wandered hole. The drilled hole is the final geometry. It has to be right the first time, the full length.
In fuel-system bores, the drilled surface seals, guides, and survives fatigue under thousand-bar pressure cycles. Reaming and honing strategies are part of the process plan, not afterthoughts.
Galleries and manifolds mean holes crossing holes; every intersection is a burr and a chip trap, to be engineered out in the process.
| Parameter | Capability |
|---|---|
| Diameter range | Ø2 – 40 mm |
| Maximum depth | 6,000 mm (6 m) — drilled from both ends, meeting in the middle |
| Hole deviation | ≤ 0.8 mm over a 3,000 mm single-pass run |
| Depth-to-diameter ratio | Beyond 600:1 in the Ø3–10 mm range — production work |
| Materials | High-strength steels, stainless, superalloys (Inconel 718), titanium |
| Typical parts | Drill collars, ACPR resistivity tools, common-rail pipes, hydraulic manifolds & galleries, mold cooling channels |
| Angled / space gun drilling | Antenna holes, sealing holes and galleries at compound angles — on the 7-axis machine, to the same depth discipline |
| Equipment | 13 gun drills, all designed and built in-house — deepest holes on the 7-axis FWZ-M2030B class |
Proof, in numbers:
Gun drilling is where this company’s machine-building story began — literally.
The common-rail unit program did not just need long holes; it needed precision holes in high-strength steels, at lengths no available machine could hold. When both the technology and the machines were closed to us, we built our own — and among them was a 7-axis CNC gun drill, 6-meter drilling depth, born from a part no one would teach us to make.
That origin still shows in how we run the process today: drill bushing wear is a monitored parameter, not a surprise; coolant chemistry is a controlled variable, not a consumable; and when a hole drifts, the people diagnosing it understand the machine down to its design intent — because they designed it.
Full machine-building story: Custom Machine Tools →
| Application | Why gun drilling | Our record |
|---|---|---|
| Marine fuel systems | Common-rail pipes — thousand-bar fatigue cycles demand functional bore finish | Built when the technology and equipment could not be bought; certified by 7 classification societies; in service aboard China’s polar research vessel |
| Hydraulic manifolds | Intersecting galleries in valve & control bodies | In production — hydraulic control unit bodies for downhole tools |
| Mold cooling channels | Conformal cooling bores in large molds | Our company began as a tooling & mold shop in 1993 — cooling channels are in our DNA |
| Rotary-steerable drilling & logging systems | Antenna-hole passages in drill collars | In production |
Extreme ratios are our daily work — beyond 600:1 in the Ø3–10 mm range, and depths to 6,000 mm at small diameters. The achievable ratio depends on diameter and material; send the drawing and we will tell you honestly what is achievable.
We do not quote numbers before seeing the print — diameter, depth, and material decide the answer. For reference: hole tolerance ±0.02 mm, bore finish Ra 1.6 μm, straightness 0.5 mm/m — and hole deviation within 0.8 mm over a 3,000 mm single-pass run. Our gun drill was built in-house for a thousand-bar fuel-system application; precision holes are where this machine came from.
Cross-hole and gallery work is part of our hydraulic manifold production — angled holes run on the 7-axis CNC gun drill we built in-house, covering −90° to +90° with an angular tolerance of ±3′.
Yes — single-piece research and prototype work runs through our Custom Manufacturing line, built for research institutes. Batch fuel-system and hydraulic work runs on the production floor.
Yes — full-service from our material, or your supplied blanks.
Upload your drawing — fuel-system bore, manifold gallery, or cooling channel. Within 24 hours, an engineer responds with process feedback.
Related: Capabilities Hub｜Deep-Hole Drilling (BTA)｜Marine｜Custom Machine Tools
