UNISIG is a leading manufacturer of deep hole drilling machines and automation systems for industries ranging from aerospace to medical to mold making. Built on engineering innovation and in-house manufacturing, every UNISIG system reflects a commitment to precision, performance, and reliability.
02

Apr

UNISIG: MANUFACTURER OF DEEP HOLE DRILLING MACHINES

UNISIG is a leading manufacturer of deep hole drilling machines and automation systems for industries ranging from aerospace to medical to mold making. Built on engineering innovation and in-house manufacturing, every UNISIG system reflects a commitment to precision, performance, and reliability.

Designed to combine the speed of fast delivery with the flexibility of custom configuration, the program redefines how job shops and manufacturers acquire critical gundrilling capabilities. 
05

Mar

UNISIG LAUNCHES ASSEMBLE-TO-ORDER PROGRAM FOR UNE GUNDRILLING MACHINES

UNE32-2-1000-CR

Menomonee Falls, WI – March 5, 2025 – UNISIG, a global leader in deep hole drilling machines and technology, has launched a new assemble-to-order program for its versatile UNE series gundrilling machines. Designed to combine the speed of fast delivery with the flexibility of custom configuration, the program redefines how job shops and manufacturers acquire critical gundrilling capabilities.

“Gundrilling machines are not as common as CNC mills or lathes, but that doesn’t mean customers should settle for longer lead times, compromises in performance, or poor service,” said Anthony Fettig, CEO of UNISIG. “With this new program, we’re making it easier than ever to say yes to gundrilling.”

UNISIG’s assemble-to-order initiative maintains inventory of all major components of the UNE series, allowing machines to be assembled to each customer’s exact specifications—without the waste or delays associated with pre-built stock or full custom builds. With shorter lead times, often half that of traditional build-to-order systems, customers can get precisely what they need faster.

“At UNISIG, we’re always focused on what’s next, and our assemble-to-order program is a prime example,” added Fettig. “Implementing this approach has modernized key areas of our operations by improving machine quality, shortening lead times, and giving us better visibility into service part needs and inventory management.”

This effort required deep coordination across engineering, supply chain, manufacturing, and customer service. Modular machine designs, synchronized ERP systems, and automated planning tools allow UNISIG to deliver tailored machines while maintaining tight control over quality, cost, and inventory.

About UNISIG
UNISIG is a leading manufacturer of deep hole drilling machines and automation systems, serving industries ranging from aerospace to medical to moldmaking. Known for engineering innovation and in-house manufacturing capabilities, UNISIG combines precision, performance, and reliability in everything it delivers. For more information, visit www.UNISIG.com

Download Media Kit

UNISIG maintains inventory of all major UNE platform components and builds each machine to the customer’s specifications after an order is placed. This approach shortens delivery timelines while preserving full machine capability.

Because core components are already stocked and production planning is synchronized through UNISIG’s ERP and manufacturing systems, machine building can begin immediately after configuration is finalized. Lead times are often reduced by up to 50% compared to traditional build-to-order machines.

No. Customers can configure the number of spindles, drill diameter & depth ratings, tooling systems, workholding, automation options, and other application-specific features within the UNE platform. The program balances faster delivery with application flexibility.

One of the most surprisingly productive ways to achieve high quality bore finishing in OEM production. Even experienced machinists are impressed when they see raw tubing converted into a mirror-like finish in a single pass at extremely high feed rates. This is achieved by combining two operations into a single tool and having the right machine for the job.
03

Dec

IMPROVING BORE QUALITY WITH SKIVING AND ROLLER BURNISHING

skiving and burnishing tool

Skiving and roller burnishing is one of the most surprisingly productive ways to achieve high-quality bore finishing in OEM production. Even experienced machinists are impressed when they see raw tubing converted into a mirror-like finish in a single pass at extremely high feed rates. This is achieved by combining two operations into a single tool and having the right machine for the job.

The process works by using a set of floating knives on the front of the tool, followed by rollers. The diameter and finish are adjustable on the head to “dial” in the exact sizes, and the finish can be tuned by adjusting the roller pressure relative to the cutting diameter. Cutting fluid floods the tool to clear chips, and hydraulic actuation protects the finished surface as the tool retracts. The process delivers outstanding accuracy, surface durability, and repeatability across a wide range of bore sizes and production environments.

ACHIEVABLE RESULTS

The result is a highly efficient method that routinely achieves:

  • Cutting speeds up to 300 m/min (1000 SFM)
  • Feed per revolution 3 mm/rev (0.118 IPR)
  • Feed rates over 4000 mm/min (157 IPM)
  • Surface roughness Ra in the 0.2-micro-meter (8-micro-inch) range
  • Circular form as close as 0.01mm (.0004 inch)
  • Diameter tolerance IT8 – IT9

These capabilities significantly enhance surface durability, a crucial factor in hydraulic cylinder manufacturing and other critical applications.

ACHIEVABLE RESULTS

The result is a highly efficient method that routinely achieves:

  • Cutting speeds up to 300 m/min (1000 SFM)
  • Feed per revolution 3 mm/rev (0.118 IPR)
  • Feed rates over 4000 mm/min (157 IPM)
  • Surface roughness Ra in the 0.2 micro-meter (8 micro-inch) range
  • Circular form as close as 0.01mm (.0004 inch)
  • Diameter tolerance IT8 – IT9

These capabilities significantly improve surface durability which is an important factor for hydraulic cylinder manufacturing and other critical applications.

"Skiving and roller burnishing combines two operations into a single tool."

Skiving Burnishing Machine

APPLICATION AND PRODUCTION FLEXIBILITY

The process applies across a wide range of bore sizes and depths, from 30 to 500 mm (1.18 to 20 inches) and beyond 6 meters (20 feet). UNISIG has applied this method to depths over 13 meters (43 feet) in demanding oil and gas environments.

Most applications remove a small amount of material efficiently, typically around 1.5 mm (0.06 inches). When rough tubes require more cutting, a combined counterbore-skive-burnish tool may be used. Shorter parts can be processed vertically with separate skiving and burnishing tools, which simplifies setup and increases automation opportunities.

UNISIG MACHINES BUILT FOR THE PROCESS

Skiving and roller burnishing places significant demands on the machine platform, often requiring more than 100 kW (134 hp) at the tool. UNISIG machines are engineered to meet these requirements with power, rigidity, and long-term reliability.

  • S-Series machines are purpose-built for tube production, designed specifically around the skiving and roller burnishing process. Robot-ready configurations are available as a standard option.
  • B-Series BTA deep hole drilling machines support both the creation of the starting bore and the final high-quality finish, offering manufacturers a single platform for multiple operations.

Although skiving and roller burnishing is not as common as conventional drilling, milling, or turning, it is a proven method to drastically increase productivity and quality. These machine platforms allow manufacturers to fully leverage the productivity and quality advantages in high-volume production environments.

APPLICATION RANGE AND PRODUCTION FLEXIBILITY

Skiving Burnishing Machine

The process applies across a wide range of bore sizes and depths, from 30 to 500 mm (1.18 to 20 inches) and beyond 6 meters (20 feet). UNISIG has applied this method to depths over 13 meters (43 feet) in demanding oil and gas environments.

Most applications remove a small amount of material efficiently, typically around 1.5 mm (0.06 inches). When rough tubes require more cutting, a combined counterbore-skive-burnish tool may be used. Shorter parts can be processed vertically with separate skiving and burnishing tools to simplify setup and increase automation opportunities.

UNISIG MACHINES BUILT FOR THE PROCESS

Skiving and roller burnishing places significant demands on the machine platform, often requiring more than 100 kW (134 hp) at the tool. UNISIG machines are engineered to meet these requirements with power, rigidity, and long-term reliability.

  • S-Series machines are purpose built for tube production, designed specifically around the skiving and roller burnishing process. Robot ready configurations are available as a standard option.
  • B-Series BTA deep hole drilling machines support both the creation of the starting bore and the final high quality finish, offering manufacturers a single platform for multiple operations.

Although skiving and roller burnishing is not as common as conventional drilling, milling or turning, it is a proven method to drastically increase productivity and quality. These machine platforms allow manufacturers to fully leverage the productivity and quality advantages in high volume production environments.

FREQUENTLY ASKED QUESTIONS

Skiving and roller burnishing combine cutting and finishing in a single tool, allowing raw tubing to be converted into a mirror-like finish in one pass. High feed rates, adjustable tool settings, and efficient chip evacuation allow the process to achieve speeds and quality levels that exceed conventional drilling, milling, or turning.

The process supports a wide range of bore diameters from 30 to 500 mm (1.18 to 20 inches) and depths beyond 6 meters (20 feet). UNISIG has applied skiving and roller burnishing to depths exceeding 13 meters (43 feet) in demanding applications.

UNISIG S-Series machines are purpose built for tube production and designed specifically around the skiving and roller burnishing process. B-Series BTA deep hole drilling machines can also integrate this capability, enabling manufacturers to produce both the starting bore and the final high quality finish on one platform.

Mechanically efficient designs run cooler, hold tighter tolerances, and last longer. UNISIG machines are engineered with this in mind. Axis drives use direct-drive servos or high-efficiency planetary gear reducers rather than worm drives or belts on axis drives. Our high-powered geared headstocks use precision-ground, constant-mesh helical gearing, and pumped synthetic lubrication to reduce friction and improve power transmission efficiency.
18

Nov

ENERGY EFFICIENCY AT UNISIG

Energy Efficiency in the electrical engineering department

Energy efficiency is one area where everyone can agree. It is beneficial for the planet and for profits. A small gundrilling machine may have less than 20 horsepower, while a large BTA drilling machine can exceed 200 horsepower. Regardless of size, every kilowatt-hour of electricity matters. UNISIG designs machines with efficiency in mind because we believe that is how well-planned, modern machines should be built—through thoughtful engineering and design choices that reduce energy consumption and improve performance.

DESIGNING FOR MECHANICAL EFFICIENCY

Heat is the enemy. Mechanically efficient designs run cooler, hold tighter tolerances, and last longer. UNISIG machines are engineered with this in mind. Axis drives use direct-drive servos or high-efficiency planetary gear reducers rather than worm drives or belts on axis drives. Our high-powered geared headstocks utilize precision-ground, constant-mesh helical gearing and pumped synthetic lubrication to minimize friction and enhance power transmission efficiency. Our engineers focus on eliminating heat and inefficiencies at the source rather than consuming additional energy to remove them later.

DESIGNING FOR MECHANICAL EFFICIENCY

Heat is the enemy. Mechanically efficient designs run cooler, hold tighter tolerances, and last longer. UNISIG machines are engineered with this in mind. Axis drives use direct-drive servos or high-efficiency planetary gear reducers rather than worm drives or belts on axis drives. Our high-powered geared headstocks use precision-ground, constant-mesh helical gearing, and pumped synthetic lubrication to reduce friction and improve power transmission efficiency. Our engineers focus on eliminating heat and inefficiencies at the source rather than consuming even more energy to remove them later.

"Mechanically efficient designs run cooler, hold tighter tolerances, and last longer."

Panel B

SMART SYSTEMS THAT CONSERVE ENERGY

Variable Delivery Coolant Pumps: Deep hole drilling relies on cutting fluid at high pressures and flow rates to achieve accurate holes and reliable chip evacuation. If you are unsure how much is needed, you often apply too much, wasting energy in the process. Low-technology pumps rely on relief valves to regulate pressure, effectively functioning as heaters that never turn off. UNISIG high-pressure coolant pumps use variable speed drives and other variable volume delivery techniques to supply the exact amount of cutting fluid for the process, saving energy every minute the machines operate.

Regenerative Electrical Drives: When decelerating a load, the kinetic energy from moving mass must go somewhere. It can either be unloaded as heat into the braking system or conserved and reused. UNISIG uses regenerative drives for complex motion systems to conserve energy and improve dynamic performance. The motors paired with these high-technology drives offer exceptional efficiency and high power density. In many machine builds, UNISIG also employs drive systems (active line modules and active interface modules) with power factor correction and additional components to reduce electromagnetic interference, returning high-quality power to the grid.

LED Lighting: Machine enclosures are brightly lit to improve operator visibility during setup and prevent costly mistakes. UNISIG uses LED lighting, which consumes less energy and lasts longer than traditional lighting.

Sleep Modes: When idle, control systems automatically shut down transfer pumps and power units to conserve energy. Pneumatics are also turned off to prevent the use of unnecessary compressed air.

COMMITMENT BUILT INTO EVERY MACHINE

Energy efficiency is not a separate feature; it is built into every decision we make. Our repeat customers recognize the performance, precision, and service that define UNISIG, and our energy-efficient designs are simply part of the package. Thoughtful engineering, modern systems, and smarter power use all contribute to machines that run better, last longer, and deliver more value over their lifetime.

SMART SYSTEMS THAT CONSERVE ENERGY

Panel B

Variable Delivery Coolant Pumps: Deep hole drilling relies on cutting fluid at high pressures and flow rates to achieve accurate holes and reliable chip evacuation. If you are unsure how much is needed, you often apply too much, wasting energy in the process. Low-technology pumps rely on relief valves to regulate pressure, effectively becoming heaters that never turn off. UNISIG high-pressure coolant pumps use variable speed drives and other variable volume delivery techniques to supply exactly the right amount of cutting fluid for the process, saving energy every minute the machines run.

Regenerative Electrical Drives: When decelerating a load, the kinetic energy from moving mass must go somewhere. It can either be unloaded as heat into the braking system or conserved and reused. UNISIG uses regenerative drives for complex motion systems to conserve energy and improve dynamic performance. The motors paired with these high-technology drives offer exceptional efficiency and high power density. In many machine builds, UNISIG also employs drive systems (active line modules and active interface modules) with power factor correction and additional components to reduce electromagnetic interference, returning high quality power to the grid.

LED Lighting: Machine enclosures are brightly lit to improve operator visibility during setup and prevent costly mistakes. UNISIG uses LED lighting, which consumes less energy and lasts longer than traditional lighting.

Sleep Modes: When idle, control systems automatically shut down transfer pumps and power units to conserve energy. Pneumatics are also turned off to prevent unnecessary compressed air use.

COMMITMENT BUILT INTO EVERY MACHINE

Energy efficiency is not a separate feature, it is built into every decision we make. Our repeat customers recognize the performance, precision, and service that define UNISIG, and our energy-efficient designs are simply part of the package. Thoughtful engineering, modern systems, and smarter power use all contribute to machines that run better, last longer, and deliver more value over their lifetime.

FREQUENTLY ASKED QUESTIONS

Because efficiency impacts both performance and sustainability. Well-designed, efficient machines reduce waste, lower operating costs, and improve reliability.

They recover kinetic energy and, in many cases, return high-quality power to the grid.

Yes, positively. Efficient designs reduce heat, maintain precision, and extend component life, leading to improved accuracy and uptime.

Trepanning is a process used to create a hole in a workpiece by machining only the outer area of the hole, leaving an unmachined core in the center. A BTA drill creates the same hole by turning all of the material into chips, leaving no core behind. This gives manufacturers two distinct ways to create a hole from solid material.
18

Nov

WHEN IS TREPANNING THE RIGHT CHOICE?

oil field manufacturing application example

Trepanning is a process that creates a hole in a workpiece by machining only the outer area of the hole, leaving an unmachined core in the center. In contrast, a BTA drill creates the same hole by turning all of the material into chips, leaving no core behind. This provides manufacturers with two distinct ways to create a hole from solid material.

BTA drilling is simple in concept: set up the machine, drill the hole, remove the workpiece, and empty the chip hopper when it’s full. Many manufacturers choose this process for its straightforward operation and the convenience of chip recycling. Trepanning isn’t necessarily more difficult, but it requires more operator involvement. When the hole is complete, the retained core must be removed from the tool between cycles.

Trepanning and BTA solid drilling share the same coolant delivery and chip evacuation systems. Coolant is introduced around the outside of the tool, and chips are exhausted through the drill tube. In BTA drilling, coolant passes freely through the tube, carrying chips to the conveyor. In trepanning, however, chips taken by the coolant must pass by the workpiece core inside the tube. The bore quality between the two methods can be similar, but it depends on the tool design. Trepanning tools with a sufficient cutting width to engage guide pads can achieve diameter tolerances similar to solid drilling. Tools designed for the narrowest width of cut (leaving the largest core) generally produce lower bore quality. For very deep holes, a counter-rotating tool and workpiece are often used. Because the trepanning core rotates with the workpiece, it can create challenges related to vibration or unexpected loading. Once these differences are understood, the key question becomes: When is trepanning the right choice?

ADVANTAGES OF TREPANNING

Saving the Core: One of the most significant advantages of trepanning is the ability to retain the core. The core may hold value for quality inspection or certification of critical parts. Because it originates from the same piece of raw material as the finished component, metallurgical samples can be documented or kept as a coupon for future evaluation if a finished part fails. In some cases, the core can be repurposed as a smaller workpiece, offering an economic advantage. Depending on size and material, the scrap value of the core may even exceed that of chips created through solid drilling.

Less Power for Machining (Sometimes): When the center of the workpiece isn’t machined away, machining forces can be reduced compared to solid drilling. This advantage is most evident when the tool is cutting a narrow width relative to the hole size and the depth isn’t great enough for the core to bend or rub inside the drill tube, which would otherwise create friction and require more power.

Better Economics in Tooling: Since trepanning does not machine the hole center, a center carbide insert isn’t required, and in some cases, the intermediate insert can also be eliminated. This can lead to significant tooling cost savings in production environments.

ADVANTAGES OF TREPANNING

Saving the Core: One of the most significant advantages of trepanning is the ability to retain the core. The core may hold value for quality inspection or certification of critical parts. Because it originates from the same piece of raw material as the finished component, metallurgical samples can be documented or kept as a coupon for future evaluation if a finished part fails. In some cases, the core can be repurposed as a smaller workpiece, offering an economic advantage. Depending on size and material, the scrap value of the core may even exceed that of chips created through solid drilling.

Less Power for Machining (Sometimes): When the center of the workpiece isn’t machined away, machining forces can be reduced compared to solid drilling.This advantage is most evident when the tool is cutting a narrow width relative to the hole size and the depth isn’t great enough for the core to bend or rub inside the drill tube, which would otherwise create friction and require more power.

Better Economics in Tooling: Because trepanning does not machine the hole center, a center carbide insert isn’t required, and in some cases, the intermediate insert can also be eliminated. This can lead to significant tooling cost savings in production environments.

“Trepanning is not just an alternative to BTA drilling—it’s a strategic choice when core recovery, power efficiency, or tooling economy align with production goals.”

trepanning machine application for oil field

LIMITATIONS AND CONSIDERATIONS

Core Management: Managing and removing the core can be challenging, especially in long workpieces. The end face of the core typically has a sharp, blade-like edge from the final cut. Operators should be properly trained and handle the cores carefully to avoid injury, and the cores must be safely managed as they move through the plant after drilling. The tool head can also be damaged during core removal. Carbide inserts and cartridges should be inspected after each cycle to ensure they are ready for the next workpiece.

Cutting Insert Changes During the Cut: If a cutting insert dulls during trepanning, it’s difficult to index the insert mid-cycle. The tool must be retracted, often with the core still in contact with the inserts that were cutting it. In contrast, a solid-drilled hole allows the tool to be backed out, inserts replaced, and drilling resumed more easily.

Blind Holes: When a hole extends completely through the part, trepanning is straightforward to implement. When a hole is blind—only partially into the workpiece—the core remains attached at the bottom. Special core-breaking strategies or core-cropping tools can separate the core, but these add process complexity.

Chip Clearance Between Core and Drill Tube: The trepanning process leaves a core in the center of the drill tube while producing the hole, which has to compete for space with the chips exiting through the tool. Chip control is crucial, as is managing the wall thickness of the drill tube to ensure compatibility with the trepanning head, targeted hole size, and cutting width.

EQUIPMENT FOR TREPANNING

Many older trepanning machines were designed around lower power requirements and may not be suitable for modern BTA solid drilling. Likewise, trepanning tools designed for high penetration rates or small cores can stress older machines not built for that level of performance. UNISIG B-Series machines are designed to support both trepanning and BTA solid drilling. This gives manufacturers flexibility to choose the process that best fits their production goals—whether prioritizing material recovery, process efficiency, or overall machine utilization.

LIMITATIONS AND CONSIDERATIONS

trepanning machine application for oil field

Core Management: Managing and removing the core can be challenging, especially in long workpieces. The end face of the core typically has a sharp, blade-like edge from the final cut. Operators should be properly trained and handle the cores carefully to avoid injury, and the cores must be safely managed as they move through the plant after drilling. The tool head can also be damaged during core removal. Carbide inserts and cartridges should be inspected after each cycle to ensure readiness for the next workpiece.

Cutting Insert Changes During the Cut: If a cutting insert dulls during trepanning, it’s difficult to index the insert mid-cycle. The tool must be retracted, often with the core still in contact with the inserts that were cutting it. In contrast, a solid-drilled hole allows the tool to be backed out, inserts replaced, and drilling resumed more easily.

Blind Holes: When a hole goes all the way through the part, trepanning is straightforward to implement. When a hole is blind—only partially into the workpiece—the core remains attached at the bottom. Special core-breaking strategies or core-cropping tools can separate the core, but these add process complexity.

Chip Clearance Between Core and Drill Tube: The trepanning process will leave a core in the center of the drill tube while producing the hole, which has to compete for space with the chips exiting through the tool. Chip control is very important, as is managing the wall thickness of the drill tube to be compatible with the trepanning head, targeted hole size, and cutting width.

EQUIPMENT FOR TREPANNING

Many older trepanning machines were designed around lower power requirements and may not be suitable for modern BTA solid drilling. Likewise, trepanning tools designed for high penetration rates or small cores can stress older machines not built for that level of performance. UNISIG B-Series machines are designed to support both trepanning and BTA solid drilling. This gives manufacturers flexibility to choose the process that best fits their production goals—whether prioritizing material recovery, process efficiency, or overall machine utilization.

FREQUENTLY ASKED QUESTIONS

Trepanning is ideal when core recovery or reduced tooling cost is valuable, or when material properties must be preserved for testing or reuse.

It’s possible, but challenging. Specialized core-breaking or cropping tools are required to separate the core, which adds time and complexity.

Machines must be powerful, and designed for core handling. UNISIG B-Series machines can perform both trepanning and BTA drilling, offering flexibility for different applications.