About UNISIG

Used UNISIG CNC Machines for Sale

Resell CNC is your Simple. Reliable. and Trusted.® source for used UNISIG gundrilling machines, BTA deep hole drilling machines, skiving and burnishing machines, off-center drilling machines, and combination drilling and milling centers. UNISIG equipment occupies a narrow, high-value corner of the metalcutting world: holes that are too deep, too straight, or too tightly toleranced for a conventional machining center to produce. Shops that win that kind of work build their processes around these machines, which is why used UNISIG equipment tends to find a new home quickly.

UNISIG was founded in 1981 in Elgin, Illinois as a venture between Schweizerische Industrie Gesellschaft (SIG) of Switzerland and the American firm United Technical, formed to bring European deep hole drilling technology and application support to North American manufacturers. In 1995 the brand was acquired by Entrust Manufacturing Technologies, Inc., a machine builder started in 1973 by John Korosec, and operations moved to the Entrust campus in Menomonee Falls, Wisconsin, just outside Milwaukee. Entrust reinvested heavily in the line, and the modern UNISIG catalog is the result: machines designed, engineered, and assembled in Wisconsin, backed by in-house mechanical and electrical engineering, CNC machining and grinding, fabrication, and precision calibration.

Today UNISIG is one of the largest producers of deep hole drilling equipment in the world. Its global headquarters sits on Shawn Circle in Menomonee Falls, and a European subsidiary, UNISIG GmbH, was established in Bad Urach, Germany in 2011. The Wisconsin campus grew past 100,000 square feet, and includes 50 ton cranes plus a 12 meter (42 ft) high bay for assembling the largest column-type machines. Across the product line, UNISIG machines are rated for holes from under 1 mm to roughly 1 meter in diameter, at depths from a few inches to more than 65 feet, using gundrilling, BTA, ejector, trepanning, counterboring, skiving, reaming, and rifling processes. Machine designations follow a readable pattern: a UNE32-2-1500-CR, for example, is a UNE-series gundrilling machine rated to 32 mm, with two spindles and a 1,500 mm rated workpiece length.

Have a UNISIG you no longer run? Resell CNC buys UNISIG deep hole drilling machines outright, accepts them on consignment, and sells them through our auctions. We handle appraisal, rigging, transport, and marketing, and we know how to describe and position this equipment for the buyers who actually need it. Call (844) 478-8181 or email sales@resellcnc.com for a free, no-obligation appraisal of your UNISIG.

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UNISIG Gundrilling Machines

Gundrilling uses a single-flute tool with internal high-pressure coolant and an external chip flute, which makes it the preferred process for smaller diameters at long lengths. UNISIG's UNE series covers roughly 1.4 mm to 40 mm and rated workpiece lengths from 750 mm to 3,000 mm, with single and twin spindle configurations. Twin spindle models can often be run in single spindle mode at a larger maximum diameter, which is worth confirming on any used machine you evaluate. The UNE6 medical variants are built for drilling small, tough workpieces after Swiss turning.

UNISIG BTA Deep Hole Drilling Machines

BTA (also called STS) drilling pushes coolant down the outside of the tube and evacuates chips through the center, which supports much larger diameters and higher metal removal rates than gundrilling. UNISIG's B-series covers on-center drilling of round workpieces, split into models under 800 mm swing and over 800 mm swing. UNI production machines handle gundrilling, BTA, or both, and are frequently paired with conveyors, gantries, or robots. USC column-type machines take on non-round parts weighing up to 50 tons, and USC-TS tube sheet configurations use multiple spindles to drill the thousands of holes a heat exchanger tube sheet requires.

Skiving, Off-Center, and Specialty Machines

The S-series skiving and roller burnishing machines finish the bore of hydraulic cylinder tube in a single pass, producing the surface finish and roundness that cylinder manufacturers demand. USK knee-type and UNX cylindrical machines drill off-center holes in a wide range of workpiece shapes. USC-M models combine deep hole drilling with milling in one setup, a favorite for mold and die shops. On the firearms side, UNR reaming machines and R-series rifling machines cover barrel blank production, and R-Cell configurations tie those steps into a single production cell.

Who Buys Used UNISIG Equipment

Demand for used UNISIG machines comes from aerospace and defense suppliers, oil and gas and downhole tool manufacturers, energy and power generation fabricators, hydraulic cylinder producers, mold and die shops, medical device manufacturers, firearms and barrel makers, and general job shops adding deep hole capability without a new-machine lead time. Because these machines are purpose-built, condition and configuration matter more than age. A well-maintained machine with the right diameter range, workpiece capacity, and tooling package is often the better buy.

UNISIG — Brand Quick Facts
Founded	1981, Elgin, Illinois, USA
Headquarters	Menomonee Falls, Wisconsin, USA
Parent Company	Entrust Manufacturing Technologies, Inc. (acquired the UNISIG brand in 1995)
US Operations	Engineering, machining, fabrication, and final assembly at the Menomonee Falls campus (100,000+ sq ft). European subsidiary UNISIG GmbH in Bad Urach, Germany.
Best Known For	Deep hole drilling. Gundrilling and BTA machines that hold straightness and diameter tolerance at extreme depth-to-diameter ratios.
Popular Models	UNE12-2, UNE20-2, UNE25, UNE32-2, UNE40, UNE6 series, UNI-25BTA, B500, B600, B700, B1000, B1200, S700, USK25, UNX, USC-M, USC-TS, UNR-12-2, R50
CNC Controls	Siemens SINUMERIK is the most common platform, running UNISIG deep hole drilling process screens and cycles. Older machines may carry earlier Siemens or Fanuc controls.
Hole Range	Under 1 mm to roughly 1 m diameter; depths from a few inches to over 65 ft
Processes	Gundrilling, BTA/STS, ejector drilling, trepanning, counterboring, pull boring, bottle boring, skiving and roller burnishing, reaming, rifling, milling
Industries Served	Aerospace, defense, firearms, oil and gas, energy, automotive, medical, mold and die, hydraulic cylinders, job shops

Buying Guide: What to Inspect on a Used UNISIG

Deep hole drilling machines are judged differently than machining centers. What matters is whether the machine starts a hole true and holds it straight over hundreds of diameters of depth. Four areas tell you most of it.

Coolant system and filtration. The heart of the machine, and the first thing to suffer from neglect. Check pump pressure at the spindle, filtration media, chip conveyor, tank cleanliness, and whether the chiller holds temperature. Ask what oil the machine ran and whether it was filtered on a schedule.

Whip guides, bushings, and steady rests. Long tools need support. Worn bushings, damaged whip guide inserts, or steady rests that no longer clamp concentrically show up as runout, bell-mouthing, or broken tools. Inspect pressure head and seal condition and confirm guide and bushing sets exist for your diameters.

Spindle, headstock, and slide alignment. Ask for a straightness sample or recent test part. On a BTA machine, check headstock rotation for runout and listen for bearing noise under load. Inspect ways and ball screws along the full stroke, since these machines often live in one portion of travel.

Control, drives, and documentation. Confirm the control powers up cleanly, drives are healthy, and parameter backups, ladder files, and manuals are included. Missing documentation and missing tooling are what turn a good machine into a slow start-up.

UNISIG Machine Series

UNE Series Gundrilling Machines

The compact, job-shop-friendly line. UNE12-2 and UNE20-2 are twin spindle machines for small diameters at high tool speeds, with the UNE12-2 reaching 12,000 RPM. UNE25 and UNE40 are single spindle, and UNE32-2 is rated to 32 mm per spindle or 40 mm in single spindle mode. Rated workpiece lengths run 750 mm through 3,000 mm. Suffixes describe configuration: FT is a universal workpiece table and CR a chip conveyor arrangement, with the middle number giving rated workpiece length in millimeters. UNE6 models are the medical variants.

UNI Production Machines

Single and multi-spindle production machines configurable for gundrilling, BTA, or both. UNI machines are the line most often integrated with automation such as conveyors, gantry loaders, and robot cells, and they show up in automotive and high-volume component work.

B-Series BTA Machines

On-center BTA drilling of round workpieces, organized by swing. Models under 800 mm swing (B500, B600, B700) handle the bulk of general BTA work. Larger models (B1000, B1200 and up) take longer, heavier parts while holding straightness at extreme depth. B-series machines anchored the UNISIG Express program launched in 2007 to shorten build times, so they are the most widely installed BTA machines in the line.

S-Series Skiving and Burnishing Machines

Built for hydraulic cylinder tube finishing. A skiving head removes stock and a roller burnishing head follows to produce a hard, mirror-like bore in one pass. On an S700 or similar, look closely at head condition and available tooling sizes, since tooling drives the range of tube diameters you can run.

USK, UNX, USC, and Barrel Production Machines

USK knee-type machines drill off-center holes with a moving table, and UNX machines handle off-center work on cylindrical parts. USC column-type machines are the heavy end of the line, drilling non-round workpieces up to 50 tons. USC-M variants add milling in the same setup for mold and die shops, and USC-TS tube sheet machines run multiple spindles for heat exchanger work. Verify foundation, crane capacity, and power first. On the firearms side, UNR machines ream barrel blanks and R-series machines including the R50 handle servo-driven rifling.

Sell Your UNISIG to Resell CNC

UNISIG machines hold value well because secondary-market supply is thin and buyers are specific. Resell CNC reaches those buyers. We purchase outright, take consignments, and run auctions, and we manage appraisal, rigging, transport, and marketing. Our listings describe deep hole capability accurately, which is what separates a fair offer from a lowball one.

1. Contact us. Send model, serial number, control, tooling, and a few photos.
2. Get an appraisal. We evaluate condition, configuration, and demand, then give you a number and your options: outright purchase, consignment, or auction.
3. Accept. Paperwork, payment, rigging, and removal happen on your schedule.

UNISIG Frequently Asked Questions

Are used UNISIG machines reliable?

Yes, and reliability is a large part of why the brand commands a premium. These machines are designed and assembled in Wisconsin with heavy, rigid structures. Failure points on a used machine are usually consumable systems: coolant pumps, filtration, seals, bushings, and whip guides, not the core structure. A machine with documented maintenance history is generally a safe buy.

What controls do UNISIG machines use?

Siemens SINUMERIK is the dominant platform, with UNISIG's own deep hole drilling screens and cycles on top, so operators familiar with SINUMERIK adapt quickly. Older machines may carry earlier Siemens generations or Fanuc. Confirm the exact control before buying, since parts availability follows it.

What is the difference between gundrilling and BTA on a UNISIG?

Gundrilling uses a single-flute tool with coolant fed through the tool and chips evacuated along an external flute, which suits smaller diameters at very high depth-to-diameter ratios. BTA feeds coolant around the drill tube and evacuates chips through the center, allowing larger diameters and higher removal rates. UNE machines gundrill, B-series and USC are BTA, and UNI machines can be either.

Which used UNISIG models offer the best value?

The UNE series is usually the most accessible entry point for a shop adding deep hole capability: compact, widely installed, simple to support. Among BTA machines, the smaller B-series models are the most common on the used market. Specialty machines like USC-TS, UNR, and R-series are excellent buys if your work matches them and poor buys if it does not.

What should I check before buying a used deep hole drilling machine?

Start with coolant and filtration, then whip guides, bushings, and steady rests, then spindle and slide condition, then the control and its documentation. Confirm the tooling covers your diameter range.

Do you offer financing on used UNISIG machines?

Yes. Financing is available on used equipment purchases, which lets you preserve working capital while adding capability. Visit our financing page for options, or call and we will walk you through what works for a machine in this class.

How much is my used UNISIG worth?

Value depends on model, configuration, hours, tooling, control generation, and demand in the industries that use the machine. Because the market shifts, we do not publish figures. Call (844) 478-8181 for a free appraisal.

How do I sell my UNISIG machine?

Call (844) 478-8181 or email sales@resellcnc.com with model, serial number, control, and photos. We appraise it, present your options, and handle rigging and removal once you accept.