Gun Drilling Machines

Deep hole drilling machines for injection molds, automotive shafts, rods and axles, and heat exchanger tube sheets.

LPR’s Gun Drilling Machines create straight, precise holes with 2-32 mm hole diameter and up to 1500 mm drilling depth, resulting in high depth-to-diameter ratios of 1:100 and 1:200. Our machines are widely used by moldmakers, job shops, and parts manufacturers in the mold & die, automotive, medical, and metalworking industries. Gun drilling can be used with a variety of materials including aluminium, alloy steel, stainless steel, titanium, cast iron, copper alloys, and more.


Our CE and ISO-certified manufacturing site in South Korea, with 30+ years of experience, has provided over 600 standard and custom-built gun drilling machines. Local machine installation and after-sales support are provided across North America. Contact us to discover how our gun drilling machines can improve your hole tolerance and surface finish.

Precision CNC Gun Drills | Deep Hole Drilling Machines


Gun Drilling Machines use long, thin cutting tools to create high depth, low diameter holes in metal workpieces. Coolant is supplied through a small hole within the tool and chip removal occurs through a groove on the outside of the tool. LPR Global provides complete solutions for deep hole drilling including gun drilling machines, combined gun drilling and BTA drilling machines, and high precision solid carbide tooling made in-house. We have supplied machines to parts manufacturers and job shops around the world in USA, Australia, Czech Republic, Romania, Vietnam, Indonesia, China, India, Taiwan and Japan.

Gun Drilling Machine Advantages

  • Complex holes of various depths and diameters can be produced, such as overlapping holes, cross holes, tilted holes, multiple diameter holes, and holes on angular, round or curved surfaces.
  • Using solid carbide-tipped gun drills to improve drilling speed, our machines can produce a high quality surface finish (Rmax 8-25S for S45C steel). This eliminates the need for secondary machining operations and creates a finished hole in just one pass.
  • Precise tolerances for hole diameter, straightness and cylindricity are achieved, producing burr-free holes as small as 2 mm in diameter.
  • Self-piloting drills and precise drill guide bushings minimize drift and maintain hole straightness of 1 mm per depth of 1000 mm.

Deep Hole Drilling Applications | Axles, Mold Bases, Heat Exchanger Tube Sheets

  • Automotive components: cylinder heads, input shafts, output shafts, pinion gears, steering shafts, gear shafts, rack bars, balancing shafts, fuel injector bodies, fuel rails
  • Injection molds: ejector pin holes, coolant holes, hot runner manifolds, plastic molds, metal molds, carbon molds
  • Medical, petrochemical and industrial parts: orthopedic devices, heat exchanger tube sheets, heat exchanger baffles, sleeve pins, hydraulic manifolds

Die Cast Mold (DAC-P Steel)

Drill Diameter: 11.02 mm

Cutting Speed: 30 m/min

Feed: 0.028 mm/rev

Coolant Pressure: 50 kgf/cm2

Coolant Type: Oil

Forged Rack Bar (S45C Steel)

Drill Diameter: 12.02 mm

Cutting Speed: 60 m/min

Feed: 0.064 mm/rev

Coolant Pressure: 60 kgf/cm2

Coolant Type: Oil

Input Shaft (S45C Steel)

Drill Diameter: 8.00 mm

Cutting Speed: 80 m/min

Feed: 0.024 mm/rev

Coolant Pressure: 80 kgf/cm2

Coolant Type: Water-soluble

Gun Drilling & BTA Drilling Machines | Specifications PDF Icon

Our product line consists of column-type and knee-type gun drilling machines and combined gun/BTA drilling machines that are ideal for large or heavy workpieces. The BTA drilling process covers a diameter range of 16-65 mm with a maximum drilling depth of 1,800 mm. We have sold over 600 machines since our inception, including 30+ standard models for mold & die, automotive, and heat exchanger applications. We also provide custom-built machines based on the customer’s workpiece, cycle time and preferred transfer systems.


  • Built with high grade cast iron, making them extremely durable over an average service life of 20-30 years.
  • FANUC 3-axis CNC systems for greater user control over location positioning, machining depth and machining speed.
  • Additional spindles and tools can be installed for further machining processes such as surface milling, tapping and chamfering.
  • Various machine configurations and options available including workpiece rotation units, moving tables, angle plates, high precision rotary tables, one-touch hydraulic tool holders, and automated loading, parts handling and transfer systems.
Large workpieces, injection moldsWater, heat and ejector pin holes in plastic molds, hydraulic manifolds,heat exchangersSmall to medium-sized parts, small diameter holesSmall to large industrial, hydraulic and heat exchanger partsLarge or heavy industrial, hydraulic, and heat exchanger partsPrecision parts, moldsCompact machine for mass production of partsHeat exchanger tube sheets
Drilling Spindles
Drilling Diameter (mm)
GD 7-20, BTA 16-65
GD 7-20, BTA 16-65
7-32, 16-65
Drilling Depth (mm)
600 to 1,000
400 to 800
GD 1,500
BTA 2,100
GD 1,500
BTA 2,100
1,500 to 1,800
400 to 800
Spindle Motor Power (kW)
5.5 to 7.5
5.5 to 7.5
1.5 to 7.5
22 to 26
22 to 26
15 to 18
1.5 to 5.5
22 to 26
Z Axis Motor Power (kW)
Table Max. Load Capacity (kg)
6,000 to 10,000
1,000 to 2,000
6,000 to 10,000
6,000 to 25,000
1,000 to 2,500
35,000 to 50,000
Column-type gun drilling machine for large, heavy workpieces
Knee-type gun drilling machine
Compact, high precision gun drilling machine

KHG Series

Column-type gun drilling machine for large workpieces, injection mold water lines and ejector pin holes. Ideal for processing heat-treated steel, with optional spindle for tapping and chamfering.

KEG Series

Knee-type gun drilling machine with dual manual and automatic modes for multi-hole drilling in plastic molds, metal molds, hydraulic manifolds and heat exchangers.

KEXG Series

Compact, high precision gun drill for mass production of small & medium-sized parts, small diameter holes, and mold sleeve pin holes.

BTA Drilling + Gun Drilling machine for precision machining
BTA Drilling + Gun Drilling machine for large workpieces
BTA Drilling + Gun Drilling machine for heat exchangers

KHBG Series

Combined Gun + BTA Drilling machine for fast, precise machining of various workpieces and materials. Optional angle plate available for heat exchanger tube sheet drilling.

KHBW Series

Combined Gun + BTA Drilling machine with large work table for heavy workpieces up to 25 tons. Optional angle plate available for heat exchanger tube sheet drilling.

KTBG Series

Combined Gun + BTA Drilling machine for production of cooling channels in heat exchangers. Optional angle plate and V-block available.

Compact gun drilling machine for mass production of parts
4-Axis CNC gun drilling machine
Gun Drilling Machine for Automotive Parts

KDG/KIG Series

Compact gun drilling machine for mass production of parts. Comes with up to 4 spindles, built-in automatic clamping, loading and parts handling systems, and a self-contained structure to maximize floor space.

KHRG Series

4-Axis gun drilling machine with moving column, horizontal rotary table and hydraulic tool holder. Different tools can be attached for tapping, surface milling and other machining processes.

KWG Series

Specialized gun drilling machine for mass production of automotive cam shafts and input shafts, allowing drilling from either side.

Gun Drill Tools and Accessories | Specifications PDF Icon


Precise, rigid gun drill tools are essential for providing high feed rates and high cutting accuracy. We make gun drill tooling in-house for use in our deep hole drilling systems. Single flute, carbide-tipped gun drills are available from 3 mm to 30 mm with a sharp cutting edge and a wide flute for excellent chip evacuation. Fast cutting speeds and long tool life are achieved using low vibration at the tool head and reinforced drill tubes that reduce eccentricity. Tools can be easily reground using a universal tool grinder.

Gun Drilling Process Video

What is Gun Drilling and Deep Hole Drilling?

Deep hole drilling machines are metalworking machine tools that produce holes with high depth-to-diameter ratios in a variety of metals. They are designed to rotate the workpiece and/or tooling in order to create extremely straight and precise holes using self-piloting drills. Two common deep hole drilling processes are Gun Drilling, used for small-diameter holes between 1 mm and 50 mm, and BTA Drilling, used for larger-diameter holes above 20 mm.

Gun Drilling vs. BTA Drilling

Gun DrillingBTA Drilling
Hole DiameterIdeal for small diameter holes: 1-50 mmIdeal for larger diameter holes: 20-200 mm
Coolant DeliveryHigh pressure coolant enters through a hole in the center of the gun drillHigh pressure coolant flows around the outside of the BTA drill
Chip RemovalChips are discharged through a V-shaped groove on the outer surface of the gun drillChips are discharged through the center of the BTA drill

When to Use Gun Drilling

Although gun drilling machines are capable of drilling depths up to 1,500 mm, they can also be used to produce shallower holes for applications that require close tolerances for straightness, hole diameter, and surface finish.


For certain applications, gun drilling can be performed on standard CNC machining centers and lathes. However, there would be restrictions on the drilling depth and the accuracy of the results. Dedicated gun drilling and deep hole drilling machines are specifically designed with a counter-rotating mechanism to minimize hole drift, high pressure coolant system for chip evacuation, and precision guide bushing to guide the gun drill into the workpiece. This level of accuracy and superior surface finish are not possible when gun drilling on standard machine tools.

Gun Drilling Machine Components

Gun Drilling Machine Accessories

Gun Drilling Machines are equipped with key components and optional features to enhance the holemaking process. This includes drill guide bushings, whip guides, oil seal rubber gaskets and bearings that prevent gun drill vibration and whipping. Other accessories include a filter bypass, oil cooler, automatic coolant retrieval system, high pressure pumps, clamping jigs, rotational jigs, centrifugal separators, and various types of chip conveyors.

Gun Drilling Technology and Quality Assurance

Our manufacturing facility in South Korea is certified to CE, ISO 9001 and ISO 14001 standards. It was established in 1986 as a joint venture with Miroku Japan, a leading firearms manufacturer. Building off their advanced technology, we continue to invest heavily in research and development for the consistent improvement of cutting quality, tool life and machine accessories. We use high quality components from Europe including cast iron, drilling spindles and carbide shanks.


Our semi-automatic tool production line consists of NC machines and manual checks to minimize defects. Tool straightness is checked 5-6 times in a cycle to ensure high accuracy. We also perform close inspection of oil flow to achieve 100% reliability, and use isothermal and isohumidity chambers to reduce errors.


Developed an 8-axis tilted drilling and boring machine.


Developed a column-type 2-spindle gun drilling machine for mold manufacturers.


Started producing precision gun drill tooling in-house after a technology transfer from Miroku Corporation, Japan.


Exported gun drilling machines for drilling heat exchanger tube sheets to India.


Started in-house production of quick change toolholders for gun drilling machines.


Developed a combined gun drilling and BTA drilling machine.


Developed a 4-spindle CNC gun drilling machine with a moving column and precision rotary table.


Developed first gun drilling machine through a joint venture with Miroku Corporation, Japan.

Patents | Gun Drilling Machine Components

  • Clamping mechanism for an inclined machine bed
  • Chucking device for tool holder
  • Spindle for a multi-purpose gun drilling machine for additional machining operations including drilling, tapping, milling, boring and facing.
  • Spindle for a multi-purpose deep hole drilling machine, peforming both gun drilling and BTA drilling processes
  • Rotary table with backlash control for a gun drilling machine
  • Counter-rotating workpiece mechanism to improve hole straightness
  • Work table tilting mechanism to improve punching process

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