SBAL-III auto duct line lets a Melbourne sheet metal workshop quote for data-centre mechanical contractors

The workshop and the situation before the line

The buyer is a family-owned sheet metal workshop in Melbourne's eastern suburbs that has been fabricating HVAC ductwork for commercial mechanical contractors across Victoria since the early 1990s. The business had grown organically from a two-person garage operation into a seven-operator workshop with two manual lockformers, a semi-automatic rectangular duct line purchased in 2014, and a small spiral duct capability that was deliberately kept limited because the owner preferred to specialise in rectangular work. The workshop had a reputation in the Melbourne mechanical contracting community for quality and reliability on smaller commercial projects — retail fit-outs, branch offices, aged-care facilities — but had been reluctant to quote for the larger tower projects and had never quoted for a data-centre project because the throughput and tolerance demands were simply beyond what the 2014 line could deliver. The decision to invest in the SBAL-III came from a direct approach by a Tier 1 data-centre mechanical contractor in late 2024 who was looking for an additional Victorian sheet metal supplier with AS/NZS 4254 compliance and tolerances tight enough for static pressure class 3 duct. The workshop owner did the numbers, realised that the SBAL-III would pay for itself on roughly two seasons of data-centre work if the contractor's volume projections held up, and signed the purchase order in the first week of 2025.

Why the workshop chose the SBAL-III over the SBAL-V or the SBAL-II

The buyer evaluated three SBKJ auto duct lines: the SBAL-II semi-automatic, the SBAL-III, and the SBAL-V flagship. The SBAL-II would have represented only a modest step up from the 2014 line the workshop already owned and would not have delivered the AS/NZS 4254 tolerance class the data-centre contractor required. The SBAL-V was attractive because of its rated throughput but came with significant extra capital cost and a larger floor footprint than the workshop's building could accommodate without a costly extension. The SBAL-III was the clear fit: full CNC control on every forming station, tolerance envelope comfortably inside the AS/NZS 4254 Class 3 specification, throughput more than double the 2014 line it would partially replace, and a footprint that slotted into the existing workshop without structural modification. The owner's internal calculation showed the SBAL-III paying back in roughly 22 months at the volumes the data-centre contractor was projecting, with the SBAL-V paying back in roughly 34 months at the same volumes — the difference was entirely in the capital cost, not the operating cost, and the conservative choice won because the data-centre volume had not yet been committed by contract at the point of purchase.

The machine configuration

The machine selected was an SBAL-III configured for the Australian installation environment:

• Coil width: up to 1,300 mm
• Material: galvanised steel Z275 to AS 1397, 0.55–1.2 mm (the AS/NZS 4254 gauge range for commercial ductwork)
• Seam: integrated Pittsburgh lock forming, S-cleat and drive cleat options, TDF flange forming in-line
• Target output: 1,400 m²/day on a single shift at the buyer's site
• Tolerance: ±0.5 mm on finished dimensions, comfortably inside AS/NZS 4254 Class 3
• Control: Siemens PLC with 10-inch HMI, English only (no language pack required for Australia)
• Power: 415V 3-phase 50Hz — matching Australian three-phase mains (240V phase-to-neutral, 415V phase-to-phase)
• Options: automatic decoiler with hydraulic braking, integrated offcut recycling chute, workshop-standard safety fencing

Two decisions are worth calling out. First, the buyer specified AS/NZS 4254 Class 3 tolerance from day one rather than accepting the standard SBAL-III tolerance envelope and tightening it during commissioning. The data-centre contractor had been explicit that duct failing AS/NZS 4254 Class 3 at the first inspection would be rejected and returned at the fabricator's cost. Specifying the tolerance in the purchase order rather than the commissioning phase meant SBKJ ran the line through the full forming cycle on the test bay using a Z275 Australian-gauge coil that had been shipped to the Jiangyin factory specifically for the FAT. Second, the workshop specified the integrated TDF flange module rather than a standalone TDF machine downstream, for the same reason as the Vietnam case study — eliminating one handling step in the rectangular duct production sequence.

Installation timeline — 62 days from order confirmation

The timeline below is drawn from the SBKJ project file and cross-checked against the buyer's own commissioning report. Australia is one of the three SBKJ regional offices with full commissioning capability, so the final phase was handled directly out of the Box Hill North office rather than by a flying engineer from China.

• Day 0 — order confirmation. Deposit received, SBKJ Jiangyin factory scheduled the build slot, AS/NZS 4254 Class 3 tolerance specification locked in.
• Day 0–30 — factory build. Structural steel, sub-assembly, electrical cabinet, PLC configuration, TDF flange module integration. Standard SBAL-III build schedule.
• Day 31–38 — in-house test bay. Full machine run-up and no-load test using Australian Z275 coil that had been pre-shipped to Jiangyin from the buyer's Melbourne coil supplier for the FAT.
• Day 39 — factory acceptance test (FAT). The buyer sent the workshop owner and the senior operator to the Jiangyin factory. The machine ran the full SBAL-III cycle on the Australian Z275 coil, and tolerance was measured on every panel across the full AS/NZS 4254 size range. The FAT report was signed with a full dimensional record. Final payment released.
• Day 40–48 — packing and dispatch. Machine crated, loaded into a 40-foot high-cube container, trucked to Shanghai port, and cleared for export to Australia.
• Day 49–58 — sea freight and AQIS clearance. Shanghai to Melbourne with a 10-day sea transit. Container cleared Australian Quarantine and Inspection Service (AQIS) inspection on arrival at Melbourne port — SBKJ had pre-cleaned and fumigated the timber crate to Australian import standards, so no delays at the wharf.
• Day 59–62 — on-site commissioning and training. The SBKJ Australia commissioning engineer drove from the Box Hill North office to the workshop. The machine was lifted into position, levelled, connected to the 415V 3-phase supply, fired up, calibrated against the buyer's first contract coil, and the two nominated operators were trained on the HMI, the daily maintenance routine, and the changeover procedure. The machine produced its first saleable duct on day 61 and ran at full production on day 62.

First-year results — before and after

The buyer ran the SBAL-III for twelve months before agreeing to share the results for this case study. The numbers below come from the buyer's own production records and the data-centre contractor's acceptance reports, not from SBKJ measurements.

• Daily output: ~500 m² (2014 semi-automatic line) → ~1,200 m² (SBAL-III on single shift). Roughly 2.4x on a single operator.
• Operators on the production station: 3 on the 2014 line → 1 on the SBAL-III. Two operators were reallocated to install support and quality control rather than the production line itself.
• Quoted volume won: doubled on a dollar basis in the first year, primarily because the workshop was able to quote for data-centre work and larger commercial towers that it had previously declined. The 2014 line had been at roughly 70% capacity; the SBAL-III was at roughly 55% at the end of year one, leaving headroom for a second data-centre contract in year two.
• Tolerance: ±2–3 mm (2014 line) → ±0.5 mm (SBAL-III). The data-centre contractor signed off on AS/NZS 4254 Class 3 on the first batch delivered, with no rejections in the first twelve months.
• Rework rate: ~2.8% (2014 line) → ~0.5% (SBAL-III).
• Changeover time between jobs: 10–15 min (2014 line) → 2–5 min (SBAL-III). The CNC program library on the HMI removed the bulk of manual re-setting.
• AS/NZS 4254 documentation: ad-hoc on the 2014 line → dimensional record generated automatically by the SBAL-III for every batch, which the workshop attaches to its AS/NZS 4254 compliance pack on data-centre deliveries.

Challenges encountered

The project was the smoothest of the three commissioned in this case study group, largely because Australia is a mature SBKJ region with a dedicated office. Three specific challenges still came up.

First, the workshop slab was slightly out of level at one end of the line footprint. The deviation was approximately 6 mm over 4 metres — well within what a sheet metal workshop would historically accept for a 2014-vintage semi-automatic line but outside the SBAL-III's tolerance for the forming station alignment. The fix was a set of precision shims installed under the line frame during commissioning; the SBKJ Australia engineer had brought the shim set specifically because he had measured the slab on a pre-delivery site visit. A workshop installing an SBAL-III without a pre-delivery site visit would need a levelling survey done ahead of time. SBKJ has since made the pre-delivery site visit a standard inclusion for Australian SBAL-III deliveries.

Second, the workshop's existing 415V supply had a slightly marginal current capacity for running the SBAL-III simultaneously with the 2014 line during the handover period. The buyer had planned to run both lines in parallel for the first month while the operators became familiar with the SBAL-III, but the aggregate current draw tripped the workshop main breaker on the first day of parallel running. The fix was an upgrade of the workshop main breaker and the distribution board, done by a local Victorian licensed electrician in the first week. SBKJ has added an electrical supply capacity check to the Australia pre-install questionnaire as a result.

Third, the data-centre contractor's dimensional specifications were not perfectly aligned with the SBAL-III's native metric units. The contractor had specified some dimensions in nominal inches and some in metric millimetres, and the operators needed to be trained on the dimensional reconciliation logic to avoid introducing rounding errors at the CNC program entry stage. SBKJ's Australia engineer built a simple spreadsheet converter for the workshop's estimating team and the issue was closed within the first two weeks. This was a contractor-specification issue rather than an SBKJ issue but it is worth mentioning because most Australian workshops will encounter similar dimensional crossover on data-centre work.

What this case means for similar buyers

An Australian sheet metal workshop that has built a reputation on small-to-medium commercial work but has been declining larger opportunities because of tolerance or throughput limits is almost certainly within striking distance of a business case for an SBAL-III. The buyer in this case study had been effectively turning away data-centre enquiries for two years before the specific approach from the Tier 1 contractor forced the decision — had they upgraded eighteen months earlier they would have captured an additional season of data-centre margin. If you recognise your own workshop in this description, the honest conversation with SBKJ Australia is about whether the SBAL-III or the SBAL-V is the right fit, and whether AS/NZS 4254 Class 3 is the right tolerance target for your pipeline.

One more observation: this was the first SBAL-III that the SBKJ Australia office commissioned independently without a flying engineer from Jiangyin. The Box Hill North office has now run the full commissioning and training sequence on three machines and will handle every Australian and New Zealand delivery going forward. The Australia regional page covers the Box Hill North office, AS/NZS compliance and the voltage conformity details for 415V 3-phase installations.

Related resources

• SBAL-III product page — full specification for the machine described in this case study
• How to choose an auto duct production line — the decision framework SBKJ engineers use with buyers
• SBAL-V vs SBAL-III line comparison — capacity, cost and headroom
• Australia regional page — Box Hill North office, AS/NZS 4254 compliance, 415V 3-phase voltage conformity
• Quality control page — ISO 9001:2015 procedure and FAT procedure

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