NOGA MT UBACK back-machining tool working through a pilot hole

UBACK®Back-Machining System

Machine hidden rear features without flipping the workpiece. Coolant-actuated UX tool-holders carry USPOT and UCHAMF inserts for automated CNC back spotfacing, counterboring, chamfering and countersinking.

Choose your application Technical Center

UBACK at a glance

Screening values. The configurator confirms the exact holder and insert.

Application: Hidden rear featuresNo workpiece flipping
Pilot-hole range: Ø8–25 mm / 0.315–0.984″
Actuation: HydraulicInternal coolant, emulsion or air
Minimum pressure: 6 bar / 90 PSI
Insert families: USPOT + UCHAMFSpotface, counterbore, chamfer, countersink
Tool-holders: UBACK UX / DURASHIELDCorrosion-resistant platform

Compatibility: the insert series must match the UX holder series, and the axial reach must stay within the holder RFC limit.

One UBACK platform. Two rear-machining insert families.

Start from the feature you need to produce. The insert series must match the selected UX tool-holder series.

USPOT · US inserts

Back spotfacing & counterboring

Produce a flat-bottom rear spotface or counterbore through an existing pilot hole. USPOT is semi-standard: configured to the diameter, corner radius, chip-former and coating your application needs.

Flat-bottom back spotface or counterbore
Target ØD tolerance ±0.1 mm / ±0.004″
Continuous and interrupted cuts
Standard UX/USPOT envelope up to Ø57.5 mm

Explore USPOT Configure USPOT

UCHAMF back chamfering and countersinking application

UCHAMF · UC inserts

Back chamfering & countersinking

Machine hidden rear chamfers and countersinks with standard 82° or 90° UCHAMF inserts. Special angles are available for customer-specific applications.

Rear countersinking and controlled back chamfering
82° and 90° standard insert families
Special angles on request
Same coolant-actuated UX tool-holder platform

Explore UCHAMF Configure UCHAMF

Designed to remove extra setups from rear-feature machining.

The UX hydraulic mechanism turns internal coolant pressure into repeatable insert movement, so hidden features are machined from the accessible side of the part.

Single-setup machiningReach the rear face through the pilot hole instead of flipping or reclamping the part.

Automated insert movementCoolant pressure opens and retracts the insert for unattended CNC cycles.

One holder platformThe same UX holder takes USPOT or UCHAMF inserts, depending on the feature.

Pilot-hole protectionThe closed insert passes through the pilot hole before it deploys behind the part.

Continuous or interrupted cutsCommon rear-face geometries are supported, with the coolant strategy matched to the cut.

Replaceable insertsInserts change with a standard screw and pin, no mounting jig needed.

Material-specific cutting dataRecommendations cover ISO material groups, chip-formers, coatings and series feeds.

Configurator and G-codeMatch insert and holder, check the geometry and generate CNC program guidance in one place.

Series B–G cover pilot holes from Ø8 to Ø25 mm.

Choose the UX series from the pilot-hole diameter first, then check the feature diameter and axial reach against the holder and insert family.

UBACK UX tool-holder series B to G: pilot-hole range, maximum feature diameters and shank size
Series	Pilot-hole range Ød	USPOT max ØD	UCHAMF 82° max ØD	UCHAMF 90° max ØD	UX holder shank
B	8–10 mm / 0.315–0.394″	23 mm / 0.906″	17 mm / 0.669″	18 mm / 0.709″	Ø16 mm
C	11–13 mm / 0.433–0.512″	30 mm / 1.181″	24 mm / 0.945″	25 mm / 0.984″	Ø16 mm
D	14–16 mm / 0.551–0.630″	37 mm / 1.457″	29 mm / 1.142″	31 mm / 1.220″	Ø20 mm
E	17–19 mm / 0.669–0.748″	44 mm / 1.732″	34 mm / 1.339″	37 mm / 1.457″	Ø20 mm
F	20–22 mm / 0.787–0.866″	50.5 mm / 1.988″	39 mm / 1.535″	42 mm / 1.654″	Ø25 mm
G	23–25 mm / 0.906–0.984″	57.5 mm / 2.264″	44 mm / 1.732″	47 mm / 1.850″	Ø25 mm

USPOT ØD is set per application. UCHAMF 82° / 90° values are the largest standard diameters at the upper pilot size of each series.

Hydraulic insert control using the machine’s existing coolant system.

The UX holder turns pressure through the spindle into controlled insert movement, so back-machining runs as an automated CNC cycle.

Pressure controls the cutting position.

Closed during entryThe insert stays inside the holder envelope while it passes through the pilot hole.
Coolant actuates the mechanismMinimum operating pressure: 6 bar / 90 PSI.
Cut on the hidden sideUSPOT or UCHAMF machines the programmed rear feature.
Close before returnThe insert retracts before the tool comes back through the pilot hole.

Programming guidelines

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Built for more than a simple flat rear face.

UBACK handles continuous and interrupted rear features. For interrupted cuts, use the cooling and cutting-data reductions in the Technical Center.

Cylindrical bore

Rear counterbore or spotface on a cylindrical geometry.

Internal coolant

Sloped surface

Rear spotface or counterbore where the back surface is inclined.

External coolant

UBACK fully interrupted counterbore across a slot

Slot / interrupted cut

Fully interrupted rear machining across an open slot or broken surface.

External coolant · reduce cutting data

Shoulder type A

Fully interrupted shoulder geometry with reduced cutting stability.

External coolant · reduce cutting data

Shoulder type B

Alternative fully interrupted shoulder with repeated entry and exit.

External coolant · reduce cutting data

Programming, cutting data, cooling and insert technology.

The Technical Center covers USPOT and UCHAMF programming, continuous and interrupted cuts, insert replacement, cooling setup, coatings, chip-formers and cutting data by material.

Continuous cutCNC sequence and cooling logic.

Interrupted cutExternal coolant and reduced parameters.

Cutting recommendationsISO material groups and B–G series feeds.

Insert replacementStandard pin, screw and key workflow.

Cooling systemsEmulsion, air and MQL setup.

Coatings and chip-formersPL / ML / HL and coating choice.

Open the Technical Center

NOGA MT UBACK DURASHIELD tool-holder family

Built for strength, corrosion resistance and repeatable CNC use.

UBACK UX holders belong to the NOGA MT DURASHIELD platform: corrosion-resistant, passivated material that keeps its structural integrity and repeatable insert movement in demanding production.

StrengthHandles demanding cutting loads.
ToughnessReliable over repeated production cycles.
Wear resistanceLong-term holder durability.
Heat resistanceStable in machining environments.
Corrosion resistancePassivated protection for harsh conditions.
PrecisionConsistent hydraulic insert deployment.

Common UBACK selection questions

What is the difference between USPOT and UCHAMF?

USPOT is used for flat-bottom back spotfacing and counterboring. UCHAMF is used for back chamfering and countersinking, with standard 82° and 90° options plus special angles on request.

What pressure is required to operate UBACK?

The hydraulic insert mechanism requires a minimum of 6 bar / 90 PSI. The system can operate with internal coolant, emulsion or air according to the holder configuration.

What pilot-hole diameters are covered?

Standard UX tool-holders cover pilot-hole diameters from Ø8 to Ø25 mm (0.315–0.984″), organized in series B through G.

Can UBACK machine interrupted cuts?

Yes. Interrupted applications require the specific cooling strategy and cutting-data reductions defined in the UBACK Technical Center. Fully interrupted cuts use external coolant.

Can one UX holder use both USPOT and UCHAMF?

The UX platform is common to both insert families, but the insert series must match the UX holder series and the application dimensions must remain inside the holder limits.

Are the holder and insert sold together?

UX tool-holders and UBACK inserts are selected as a matched system but are supplied as separate items.

How do I select the correct UBACK tool?

Start with the pilot-hole diameter, select the corresponding UX series, then define the required rear feature and verify ØD and axial reach. The UBACK Configurator can perform this matching workflow.

Can NOGA MT support a special application?

Yes. For application review, send the part drawing or feature sketch together with workpiece material, pilot diameter, required rear-feature dimensions and machine/coolant information.

Send the application drawing and let NOGA MT check the complete setup.

Include the pilot-hole diameter, rear-feature geometry, axial reach, workpiece material and available coolant pressure. We’ll help match the UX holder, insert family and starting cutting data.

Contact NOGA MT Technical Center