Precision Folding and Forming Services

Eterna Global Solutions
C-52 Block-C, Sector 80
Noida Uttar Pradesh,
201306, India

CNC Folding & Forming Services — Precision Press Brake Bending for Sheet Metal Enclosures in India

Eterna Global Solutions LLP operates multiple CNC press brakes — Japanese and Italian machines — at its Noida manufacturing facility, providing precision folding and forming for sheet metal enclosures, server racks, telecom cabinets, battery housings, brackets, panels, and OEM assemblies. Our press brakes deliver up to 130 tonnes of bending force over a 3,100 mm bending length, forming parts as narrow as 10 mm and as wide as 3,000 mm with angular accuracy of ±0.3° and dimensional repeatability of ±0.1 mm on formed features.

What sets our bending capability apart is our investment in fixed-height (European-style) segmented tooling. Unlike conventional tooling that requires re-shimming and height adjustment for each tool change, fixed-height tooling allows our operators to swap punch-and-die combinations without recalibrating the machine — enabling complex multi-bend parts in a single setup. For buyers, this translates to shorter setup times, fewer handling steps, lower per-part cost, and tighter bend-to-bend consistency across production batches. On typical enclosure components with 6–12 bends, fixed-height tooling reduces setup time by approximately 40–60% compared to conventional press brake setups.

Every bend at Eterna is programmed from our design team’s SolidWorks CAD data, with bend sequence, back-gauge position, tonnage, and springback compensation calculated before the first part is formed. Blanks arriving from our CNC laser cutting and punching cell are formed against validated programs, with first-piece dimensional inspection on every job. We operate our press brakes on a 24-hour schedule to support tight delivery timelines, handling everything from single prototype bends to recurring production programs of 500+ units/month.

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Folding and forming overview

From flat blank to 3D formed component.

What is CNC folding and forming?

CNC folding (also called press brake bending) is the process of forming flat sheet metal blanks into 3D shapes by clamping the workpiece between a matched punch and die, then applying controlled force to create precise bends. It is the second major operation in sheet metal fabrication, following blanking (laser cutting/punching) and preceding welding, hardware insertion, and surface finishing. The accuracy of every bend directly determines whether parts fit together during assembly — making press brake precision critical to final product quality.

How Eterna forms parts

We operate multiple CNC press brakes with CNC-controlled back gauges (X, Y, R axes) that automatically position the blank for each bend in the sequence. Bend programs are generated from our SolidWorks CAD models with pre-calculated bend allowances, K-factors, and springback compensation values matched to each material type and thickness. Fixed-height segmented tooling allows complex multi-bend profiles in a single machine setup, and our operators verify first-piece dimensions against the drawing before batch production begins.

Why this matters for buyers: Because our blanking (laser/punch) and bending are under one roof, the flat patterns we cut already account for our specific press brake tooling and bend allowances. There is no disconnect between the flat blank and the formed part — which is the most common source of dimensional errors when blanking and bending are done at separate vendors.

Press brake specifications at a glance

Quantified for vendor qualification and sourcing evaluation.

130 tonnesMaximum bending force

3,100 mmMaximum bending length

±0.1 mmDimensional repeatability

±0.3°Angular accuracy

10–3,000 mmPart width range (min to max)

0.5–6.0 mmMaterial thickness range

40–60%Setup time reduction with fixed-height tooling

24-hourPress brake operation

6–12 bendsTypical enclosure part (single setup)

CNC back gaugeX, Y, R axis positioning

Japanese + ItalianPress brake origin

500+ units/moRecurring production capacity

For procurement teams: These specifications are typical of mid-to-heavy press brake capabilities suited for enclosures, racks, and structural sheet metal. Our 130-tonne capacity handles all standard enclosure bends in MS, SS, GI, and aluminium up to 6 mm. For thicker or wider parts, we can evaluate feasibility — contact info@itiseterna.com with your requirements.

Press brake equipment (click to expand)

Machines + tooling + back gauge + programming.

CNC press brakes130T • 3,100 mm • multi-axis back gauge

Our press brakes are Japanese and Italian-origin CNC hydraulic machines with servo-controlled rams and multi-axis CNC back gauges. The CNC controller stores bend programs so that recurring production jobs are recalled instantly with no re-programming.

Bending force: Up to 130 tonnes — sufficient for 6 mm mild steel, 4 mm stainless steel, and 5 mm aluminium at full bending length
Bending length: 3,100 mm between side frames — accommodates full-width 42U server rack panels (typically 600–800 mm) and telecom cabinet panels (up to 2,400 mm)
Back gauge: CNC-controlled X (depth), Y (height), R (retract) axes with ±0.02 mm positioning accuracy — ensures each bend is placed at the exact programmed distance from the sheet edge or previous bend
Ram repeatability: ±0.01 mm on ram descent — critical for consistent bend angles across a production batch
Crowning system: Automatic hydraulic crowning compensates for beam deflection on wide parts, maintaining consistent bend angle across the full 3,100 mm length

Fixed-height segmented toolingEuropean-style • quick-change • multi-bend

Fixed-height (also called “same-height” or “European-style”) tooling is our key advantage for complex enclosure parts. All punch and die segments have identical shut heights, so any combination of tool profiles can be loaded side-by-side without shimming or height adjustment — and the machine does not need recalibration when tools are swapped.

Setup time savings: 40–60% faster setup vs. conventional tooling on parts requiring 3+ different tool profiles (e.g., acute bends, hemming, gooseneck access bends on the same part)
Segmented widths: Available in 10, 15, 20, 40, 50, 100, 200, and 300 mm segments — assembled to match the exact workpiece width, with no overhang
Tool profiles in library: Standard V-dies (6–50 mm opening), acute dies, hemming dies, gooseneck punches, radius punches, flattening punches, and offset tools
Quick-clamp system: Tools are secured by hydraulic or mechanical quick-clamp — tool changeover in under 2 minutes per station
Consistency: Because all tools share the same shut height, bend depth calibration is maintained regardless of which tool combination is loaded — critical for parts with mixed bend types

Bend programming & simulationCAD-linked • springback comp. • sequence

Every press brake job is programmed offline from CAD data before the operator loads the first blank. The program defines the complete bend sequence, back-gauge positions, tonnage per bend, and springback compensation — removing guesswork from the shop floor.

Bend sequence optimization: Software determines the order of bends to avoid collisions between the part, tool, and machine frame — especially important for deep box shapes and Z-bends
Springback compensation: Material-specific overbend angles are pre-calculated (e.g., SS 304 springs back ~2–4° more than CRC at the same thickness) and applied to the program, so the operator achieves the target angle on the first attempt
Bend allowance tables: K-factor and bend deduction values are maintained per material grade and thickness, matched to our actual tooling V-die openings — ensuring flat patterns from our design team produce formed parts at the correct final dimensions
Collision simulation: For complex parts with deep returns or narrow flanges, offline simulation verifies tool clearance before production — preventing costly trial-and-error on the machine

Angle measurement & correctionDigital protractor • in-process checks

Bend angle accuracy is verified throughout the forming process using digital angle measurement tools. This ensures that the angular accuracy stated in our specifications (±0.3°) is maintained part-to-part and batch-to-batch.

Digital protractor: Used for first-piece bend angle verification at each bend station — resolution 0.05°
Go/no-go angle gauges: For high-volume production, fixed gauges provide instant pass/fail checks without measurement delay
Springback correction loop: If the first piece shows angular deviation beyond tolerance, the operator adjusts the overbend angle in the CNC program — typically converging to target within 1–2 trial bends
Batch consistency: Once the first piece is approved, CNC repeatability (±0.01 mm ram) ensures subsequent parts replicate the same angle — no drift across the batch

Buyer benefit: Fixed-height tooling + CNC back gauges + offline bend programming means a 10-bend enclosure panel that would require 3 separate setups on conventional equipment is completed in a single setup on our machines. Fewer setups = less handling = lower cost + fewer opportunities for dimensional error.

Bend types and forming techniques we perform

From simple V-bends to complex formed profiles.

Standard bending operations

Air bending (V-bend): The most common method. The punch presses the sheet into a V-die without bottoming — bend angle is controlled by punch depth. Produces bends from 30° to 175° with standard V-dies. Used for approximately 80% of all enclosure bends.

Bottom bending (coining): The punch presses the sheet fully into the die, compressing the material at the bend line. Produces tighter angular tolerance (±0.15°) than air bending but requires 3–5× more tonnage. Used for critical bends where angular precision is paramount, such as door frame alignment surfaces and gasket sealing flanges on IP-rated enclosures.

Hemming: A two-stage operation that folds a sheet edge 180° back onto itself, creating a smooth, rounded, safe edge with doubled material thickness. Standard on enclosure door edges, panel edges, and anywhere end-users handle the product.

Specialised forming operations

Z-bends (offset bends): Two bends in opposite directions creating a stepped profile. Used for overlapping flanges, panel offsets, and cable routing channels in server racks.

Channel forming (U-bend): Multiple bends creating a C or U cross-section in a single part, commonly used for structural members, cable trays, and chassis frames.

Radius bending: Progressive or single-stroke bends creating a curve rather than a sharp angle. Used for curved enclosure corners, radius panels, and aesthetic applications. Achieved using radius punch/die tooling matched to the required radius (typically R5–R50 mm).

Gooseneck bending: Using gooseneck-profile punches to reach into previously formed flanges without collision. Essential for box shapes, deep enclosures, and C-channel profiles where standard punches would collide with the already-bent flange.

Minimum bend dimensions

Our minimum inside bend radius is 1× material thickness for mild steel and galvanized steel, and 1.5× material thickness for stainless steel 304/316 and aluminium, to prevent cracking at the bend line. Minimum flange length (from bend line to sheet edge) is 4× material thickness or 6 mm, whichever is greater. These parameters are validated during our DFM review stage before any production begins.

V-die selection guide

V-die opening directly affects bend radius, required tonnage, and minimum flange length. Our standard rule: V-die opening = 6–8× material thickness. For 1.0 mm CRC, we use a 6 mm V-die. For 2.0 mm CRC, a 12–16 mm V-die. For 3.0 mm SS 304, an 18–24 mm V-die. Wider V-die openings produce larger radii and require less tonnage but need longer minimum flanges. This trade-off is managed during bend programming to optimise for the specific part geometry and tolerance requirement.

Technical note: All bend specifications follow sheet metal industry standards. Inside bend radius, minimum flange, and tonnage calculations reference DIN 6935 bend allowance methods and are validated against our actual tooling library. This ensures that what our design team models in SolidWorks is what the operator produces on the press brake — no guesswork at the machine.

Folding production flow

From inspected blank to formed component, step by step.

Job card & bend program recall

Program loaded • tooling selected

The operator receives a job card specifying the part number, drawing revision, material, quantity, and the pre-programmed bend program ID. The CNC controller recalls the stored program, which defines every bend in sequence: back-gauge position, ram depth, tonnage, and tool station.

For new jobs: bend program is created offline by the design/programming team and transferred to the machine before production
For recurring jobs: program is recalled from the CNC controller memory with no re-programming — ready to produce within minutes
Job card cross-referenced against drawing revision to prevent forming an outdated revision

Tool setup & alignment

Fixed-height tooling • quick-clamp • die alignment

The operator loads the required punch and die segments as specified by the bend program. With fixed-height tooling, multiple tool profiles are loaded side-by-side without height adjustment.

Segmented punches and dies assembled to match workpiece width — no excess tool overhang
Die aligned to punch centreline and verified with test close at low pressure
Quick-clamp secures tools in under 2 minutes per station
For complex parts requiring multiple tool profiles in sequence, all tools are loaded upfront for single-setup completion

First-piece forming & inspection

Trial bend • dimensional check • angle verification

The first blank from the batch is formed through the complete bend sequence. After forming, the operator performs a full dimensional inspection of the first piece against the production drawing.

All critical dimensions measured: bend-to-bend, bend-to-edge, bend-to-hole, and overall formed dimensions
Bend angles verified with digital protractor (±0.3° tolerance standard)
If any dimension is outside tolerance, the program is adjusted (back-gauge offset or ram depth) and a second trial piece is formed
First-piece approval recorded on job card before batch production proceeds — no batch runs without approved first piece

Batch production forming

CNC repeatability • operator monitoring

Once the first piece is approved, the operator proceeds with batch forming. CNC repeatability (±0.01 mm ram, ±0.02 mm back gauge) ensures each part replicates the approved first piece.

Operator follows the programmed bend sequence displayed on the CNC screen — machine guides the process step by step
Back gauge automatically repositions between bends — no manual measurement
Parts handled with protective gloves or non-marking clamps to prevent surface damage on coated or brushed material
Formed parts stacked on padded racks or interleaved with protective film for transport to the next operation

In-process sampling & batch inspection

Random checks • drift prevention • batch release

During batch production, parts undergo random sampling inspection at defined intervals (typically every 10th or 20th part, depending on batch size and criticality). This catches any dimensional drift before it propagates through the batch.

Sampling frequency: 1-in-10 for standard batches, 100% for first articles and critical safety-related bends
Measurements recorded on batch inspection record: bend angle, key linear dimensions, and visual quality
If drift is detected, production pauses, the program is adjusted, and the operator re-verifies before resuming
Batch released to next operation (welding, hardware insertion, or finishing) only after final inspection sign-off

Downstream handoff: Formed parts proceed to Fabrication & Welding, Hardware Insertion, or directly to Powder Coating depending on the product routing — all operations within our Noida facility.

Materials we bend

Grades, thicknesses, and bending considerations.

Ferrous metals

Cold Rolled Steel (CRC/CRCA): IS 513-D, 0.5–4.0 mm. The most commonly bent material at Eterna. Excellent formability, predictable springback (~1–2° at 90°), and consistent results. Standard for indoor enclosures, server rack panels, brackets, and internal structural parts.

Hot Rolled Steel (HRC): IS 2062 Gr. E250, 2.0–6.0 mm. Bent for heavy-duty base frames, mounting brackets, and structural gussets. Higher springback than CRC (~2–3°), requiring adjusted overbend angles in the program.

Galvanized Steel (GI/GP): IS 277, 0.6–3.0 mm. Standard for outdoor telecom cabinets and battery enclosures. Bends well with care to prevent zinc flaking at the bend line on tight radii. Minimum inside radius 1.5×t recommended to preserve zinc coating integrity.

Stainless Steel: SS 304 and SS 316, 0.5–4.0 mm. Significantly higher springback than mild steel (~3–5° at 90°) and requires approximately 50% more tonnage. Our bend programs include material-specific springback tables for SS grades to achieve target angles on the first piece.

Non-ferrous metals

Aluminium: 5052-H32 and 6061-T6, 0.8–4.0 mm. 5052-H32 bends well with standard radii. 6061-T6 is significantly less formable and requires larger bend radii (min. 2×t to 3×t) to prevent cracking. We advise on grade selection during DFM review based on the required bend geometry.

Copper and brass: Bendable on our press brakes in thicknesses up to 3.0 mm. Soft materials with low springback, but require non-marking tooling (polyurethane die inserts) to prevent surface damage on decorative or electrical-grade applications.

Tonnage reference

Approximate press brake tonnage per metre of bend length (for air bending with 8×t V-die opening):
1.0 mm CRC: ~7 tonnes/m
2.0 mm CRC: ~25 tonnes/m
3.0 mm CRC: ~55 tonnes/m
2.0 mm SS 304: ~38 tonnes/m
3.0 mm SS 304: ~82 tonnes/m
Our 130-tonne capacity comfortably handles these loads at full bending length (3,100 mm) for all standard enclosure thicknesses.

Material sourcing: Sheet metal sourced from JSW Steel, Tata Steel, SAIL, Jindal Stainless, and POSCO-certified distributors. Our bend allowance and springback data is calibrated to these specific supplier materials, ensuring consistency between design-predicted dimensions and shop-floor results.

Quality control in folding and forming

Inspection, maintenance, and traceability.

Inspection methodology

Every forming job follows a first-piece approval + in-process sampling discipline. The first piece is fully dimensionally inspected against the production drawing. Critical measurements include bend-to-bend distances, bend-to-hole positions, overall formed dimensions, and bend angles. Subsequent parts are randomly sampled (1-in-10 standard, 100% for critical applications). All measurements are recorded on the job card and retained for traceability.

Machine maintenance and calibration

Press brakes undergo monthly preventive maintenance covering hydraulic system checks, ram parallelism verification, back-gauge calibration, and crowning system verification. Tooling is inspected for wear (punch tip radius and die shoulder radius) on a weekly cycle — worn tools produce inconsistent bend angles and are replaced before they affect part quality. Annual third-party calibration of CNC axes ensures long-term positional accuracy.

Measuring instruments

Digital protractor (0.05° resolution), digital vernier calipers (±0.01 mm), height gauges, inside micrometers, depth gauges, steel rules, and go/no-go angle templates. All instruments calibrated annually per ISO 17025 traceable standards. For first-article inspections, full dimensional reports can be generated with measurement data per drawing callout.

Why folding accuracy matters downstream

A bend that is off by 0.5° or 0.3 mm may seem minor on a single part — but when 6 formed parts come together in a server rack or enclosure assembly, those errors compound. A door that doesn’t close flush, a rail that doesn’t align, or a gasket that doesn’t seal can all trace back to a bending error. This is why we invest in first-piece verification, CNC repeatability, and calibrated tooling — to ensure that every formed component fits correctly at assembly.

No job is too small: We cater to single-piece prototypes and small batch orders (even 5–10 pieces) alongside high-volume production runs. Setup efficiency from fixed-height tooling means small batches are economically viable without excessive setup charges. We also have capacity to run extended hours and 24-hour shifts for large or urgent jobs.

Frequently asked questions

Press brake bending and sheet metal forming queries.

What is the maximum bending capacity at Eterna?+

Our CNC press brakes deliver up to 130 tonnes of bending force over a maximum bending length of 3,100 mm. This handles mild steel up to 6 mm, stainless steel up to 4 mm, and aluminium up to 5 mm at full length. For shorter bend lengths, we can handle proportionally thicker materials. Parts can range from as narrow as 10 mm to as wide as 3,000 mm.

What bending tolerance does Eterna hold?+

Standard dimensional repeatability is ±0.1 mm on formed features (bend-to-bend, bend-to-edge, bend-to-hole). Angular accuracy is ±0.3° with air bending and ±0.15° with bottom bending (coining). These tolerances meet the requirements of ISO 2768-m for general sheet metal fabrication and are sufficient for enclosures, server racks, and precision OEM assemblies.

What is fixed-height tooling and why does it matter?+

Fixed-height (European-style) tooling means all punch and die segments have identical shut heights, regardless of the tool profile. This allows our operators to load multiple different tool shapes side-by-side without recalibrating the machine — enabling complex multi-bend parts to be completed in a single setup. For buyers, this means 40–60% faster setup times, lower per-part cost on complex components, and tighter consistency across bends because the machine calibration is maintained throughout the job.

What is the minimum bend radius Eterna can achieve?+

Minimum inside bend radius is 1× material thickness (1t) for mild steel and galvanized steel, 1.5t for stainless steel 304/316, and 1.5–3t for aluminium depending on grade and temper (5052-H32 allows tighter radii than 6061-T6). Going below these minimums risks cracking at the bend line. Our DFM review identifies bend radius issues before production and recommends adjustments where needed.

Can Eterna perform hemming on sheet metal parts?+

Yes. We perform hemming (180° fold) on the press brake as a two-stage operation: first an acute pre-bend (~30°), then a flattening stroke. Hemming creates a smooth, safe, doubled-thickness edge and is standard on enclosure door edges, panel perimeters, and any part where end users will handle the product. We maintain dedicated hemming dies in our tooling library for efficient production.

How does springback differ between mild steel and stainless steel?+

Springback is the tendency of sheet metal to partially return toward its original flat shape after bending. Mild steel (CRC) typically springs back 1–2° at a 90° bend, while stainless steel 304 springs back 3–5° at the same bend — roughly 2–3× more. This is because SS 304 has higher yield strength and work-hardening rate. Our bend programs include material-specific springback compensation tables so the operator achieves the target angle on the first piece without manual trial-and-error.

Does Eterna handle small batch bending orders?+

Yes. No job is too small at Eterna. We handle single-piece prototypes and small batch orders of 5–10 pieces alongside high-volume production runs of 500+ units per month. Our fixed-height tooling and stored CNC programs make small batches economically viable because setup time is minimal — the machine is ready to produce within minutes of loading the program and tooling.

What types of parts does Eterna typically bend?+

We bend components for 19″ server racks (9U–47U), telecom outdoor cabinets, IP-rated battery enclosures, wall-mount data racks, electrical panel enclosures, OEM brackets, mounting trays, cable management panels, door frames, side panels, roof panels, base frames, internal partition brackets, and custom sheet metal assemblies. Typical enclosure components require 6–12 bends per part.

What materials can Eterna bend on its press brakes?+

We bend mild steel (CRC/CRCA, HRC), galvanized steel (GI/GP), stainless steel (SS 304, SS 316), aluminium (5052-H32, 6061-T6), brass, and copper in thicknesses from 0.5 mm to 6.0 mm. Each material has specific bend parameters (minimum radius, springback, tonnage) that are pre-programmed into our bend software to ensure accurate first-piece results.

Where is Eterna’s press brake facility located?+

Our manufacturing facility including all press brakes is at C-52, Block-C, Sector 80, Noida, Uttar Pradesh 201306, India. Press brakes operate 24 hours to support tight delivery timelines. For bending quotes and technical enquiries, contact info@itiseterna.com or +91 88004 99646.