Armored cable (SWA — steel wire armoured, or STA — steel tape armoured) price is set by four levers: conductor cross-section (mm²), core count, voltage class (0.6/1 kV LV, 3.6/6 kV to 8.7/15 kV MV, 11-33 kV), and armour type/grade (galvanized steel wire, steel tape, aluminium for single-core to avoid eddy currents) [S2][S4].
For LV feeder applications, the most quoted size band sits at 10-35 mm² (2-, 3- and 4-core) and 120-300 mm² for higher-current distribution, with copper conductor + XLPE insulation + PVC oversheath as the default build [S2]. MV builds extend to 11 kV, 15 kV and 33 kV classes, and prices step up sharply because of thicker insulation, semiconducting layers, and partial-discharge testing.
What the price is actually built from
An SWA cable's bill of materials is dominated by copper or aluminium conductor (60-75% of material cost at LV), then XLPE or PVC insulation, then steel armour (galvanized wire or tape), then inner bedding + outer sheath (PVC, PE, or LSZH) [S4]. Cross-section is the single biggest lever because copper content scales with mm².
Voltage class moves the quote through insulation thickness and screening, not conductor size: a 10 mm² 4-core 0.6/1 kV SWA and a 10 mm² 4-core 8.7/15 kV SWA use similar copper but the 15 kV build adds a conductor screen, insulation screen, metallic screen, and a thicker oversheath [S2]. Voltage-specific designators seen on quotes include 0.6/1 kV, 3.6/6 kV, 6/10 kV, 8.7/15 kV, 12/20 kV, 18/30 kV.
Armour choice is not interchangeable: steel-wire-armour (SWA) carries mechanical impact and is the default for direct burial; steel-tape-armour (STA) is cheaper but lower in crush resistance; single-core HV cables use aluminium-wire-armour (AWA) to prevent circulating eddy currents in the steel [S2][S4]. This is one of the most common mistakes seen on incoming purchase orders.
Common size families and what they are used for
LV sub-25 mm² armoured cable is the workhorse of building services, small commercial feeds, and light-industrial machine drops — typical cores are 2, 3, 4 and 5, with 4-core being the standard three-phase + earth configuration [S2][S5]. Common cross-sections in this band are 1.5, 2.5, 4, 6, 10, 16 and 25 mm².
LV 35-95 mm² covers larger building mains, distribution board feeders, and small transformer secondaries; 120-300 mm² covers main LV distribution feeders, large motor circuits, and substation LV tails [S2]. HDC's product menu, for example, lists 10-35 mm² armoured cable, 25-35 mm² SWA, 120/185/240/300 mm² 3-core armoured cable, and 400 mm² XLPE cable as discrete stock lines [S2].
MV armoured cable (11 kV / 15 kV / 33 kV) is the next tier, used between MV transformer and ring-main units, between MV switchgear panels, and for industrial plant incoming feeds. The copper cross-section usually starts at 25 mm² and can run to 300+ mm², with three single-core XLPE/SWA/AWA cables per phase commonly specified instead of one 3-core for ratings above ~400 A [S2].
Selection criteria that move the price
Conductor material: copper vs aluminium. Aluminium conductors at the same mm² are roughly 40-60% cheaper on conductor cost but require larger cross-sections for the same ampacity, and they change termination hardware [S2].
Insulation and sheath chemistry: PVC is the cheapest oversheath; LSZH (low-smoke zero-halogen) compounds such as H07ZZ-F add cost but are mandatory in tunnels, underground rail, offshore, and public-assembly venues where smoke toxicity is controlled [S2].
Standards alignment: cables built to IEC 60502-1 (LV) and IEC 60502-2 (MV), BS 5467, BS 6622/BS 7835, or ICEA S-93-639 will cost differently depending on factory audit status. Chinese export factories often offer multiple standard build options against the same cross-section, which is the single biggest reason quote-to-quote variance exists for "the same cable" [S2].
Volume tier and reel length: standard export reels are 500 m to 2000 m. Orders below one full reel typically carry a setup surcharge; orders above several reels move into factory-direct pricing [S2].
Who armored cable is — and is not — for
Armored cable is specified for direct-buried outdoor runs, underground duct, exposed outdoor industrial runs where mechanical damage is a risk, outdoor substation interconnections, mining and quarry feeder runs, and any indoor location where the cable passes through cable tray across open floor space [S4]. The mechanical protection of SWA is the reason it is mandated by wiring rules in many jurisdictions for these routes.
It is NOT for flexible equipment connections — use H07RN-F rubber flexible cable, or SOOW/SJOOW for trailing applications [S2]. It is not for fibre runs — for armoured fibre, the spec is a stainless-steel interlock or corrugated copper armour around a regular loose-tube fibre cable, not SWA [S3]. It is also not for data/control runs on moving machinery, where flexible control cable such as SY/CY braid or chain-flex cable is the correct product.
Failure modes, limits, and installation cost
Common field failures are not conductor failures but sheath and armour failures: water ingress through a damaged PVC oversheath, corrosion of galvanized steel wire in acidic soil, and overheating from undersized cable relative to grouping/conduit derating [S4]. Specifying PE oversheath instead of PVC, or upgrading to a heavier SWA wire diameter (e.g. from 0.9 mm to 1.25 mm), addresses the first two.
Installation cost is roughly 1.5× to 3× the cable material cost on LV direct-buried runs, driven by trenching, sand bedding, warning tape, route markers, and jointing kits. Termination kits (LV gland, shroud, lugs) and through-joints add per-run fixed cost; a typical LV SWA termination kit ranges in the tens of USD per end, and that figure is fairly independent of cross-section. This means small cross-sections carry a higher installation overhead as a percentage of total cost, which is why 4 mm² SWA is rarely specified when 6 mm² or 10 mm² falls within the same derating envelope.
For comparison across the main options: PVC/SWA/PVC copper LV 4-core is the cheapest mainstream build; LSZH/SWA/LSZH adds maybe 15-25% on material for low-smoke duty; aluminium-conductor SWA is roughly 30-45% below equivalent copper on conductor cost; STA (tape armoured) is typically 10-20% below SWA at the cost of crush resistance; MV 11-33 kV XLPE/SWA is several times the LV price because of insulation and screening mass [S2].
Standards, sourcing signals, and reading the quote
The standards backbone for SWA cable is IEC 60502-1 (LV) and IEC 60502-2 (MV), with regional variants BS 5467 (LV armoured), BS 6622 / BS 7835 (MV armoured, LSZH), and ICEA S-93-639 in the Americas. Voltage designators follow IEC 60183 guidance: U0/U(Um), e.g. 0.6/1 (1.2) kV, 3.6/6 (7.2) kV, 6/10 (12) kV, 8.7/15 (17.5) kV [S2]. Conductor sizes follow IEC 60228 class 1/2 (solid/stranded) or class 5 (flexible, for H07RN-F type).
Sourcing signals worth tracking: copper LME spot (Cathode grade A) sets the index for copper-conductor SWA quotes with a typical 30-60 day lag; aluminium LME drives aluminium-conductor SWA; steel wire rod index moves the armour layer. Volume tier matters more than any other single lever — direct-factory purchase of full reels at the 1-5 km scale is consistently 20-40% below stockist/distributor price for the same cross-section [S2].
For first-pass budgeting, request three numbers from the factory: (1) conductor material and class, (2) insulation/screen/oversheath build with the standard reference, and (3) the armour wire diameter and material. The combination of those three sets the cost band before any volume or freight variable is applied. For related material pricing context, the silicone rubber upstream feedstock map shows how raw-material indices feed into other industrial polymer cable sheaths such as H07RN-F neoprene and LSZH compounds, and the PCB manufacturing cost breakdown walks through the same raw-material-driver logic for a different commodity. Reference guidance on power cable selection and control cable spec sheets is worth pulling before locking a quote.
Spec-level background on the components involved: linear guide.