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Product

instrumentation cable seriesMIL-DTL-24643/55Type J & Type T (1 Pair)Unarmoured (U) / Armoured (A)

LSTCJU / LSTCJA / LSTCTU / LSTCTA MIL-DTL-24643 LSTCJU / LSTCJA /MIL-DTL-24643/55 single-pair Type J & Type T low-smoke shipboard thermocouple cable

MIL-DTL-24643/55 (LSTCJU, LSTCJA, LSTCTU, LSTCTA) Low-Smoke Zero-Halogen Naval Shipboard Thermocouple Cable featuring a single 20 AWG Type J (Iron/Constantan) or Type T (Copper/Constantan) twisted pair, XLPO insulation, LSZH jacket,.

MIL-DTL-24643/55
Naval Low-Smoke LSZH
Fuel & Lube Oil Resistant
Marine Shipboard Duty
Order designation
LSTCJU (M24643/55-01UN)
Nominal outer Ø
5.8 mm
Weight ≈
48 kg/km
TC loop R
1.17 Ω/m
Min. bend radius
35 mm
All sizes (4)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Military spec
M24643/55
LSTCJU / LSTCJA / LSTCTU / LSTCTA
TC calibrations
Type J & Type T
Fe/CuNi (J) · Cu/CuNi (T)
Construction
1 Pair × 20 AWG
7-strand thermocouple alloy
Armour options
U or A suffix
Unarmoured or Al-braid armoured
Temperature
-30 to +105 °C
Cross-linked polyolefin (XLPO)
Voltage rating
300 V rms
1,500 V AC test voltage

Typical values for this cable type, based on MIL-DTL-24643/55 (M24643/55) / ASTM E230 — confirmed in the datasheet and quotation for your order.

Application fit

Is LSTCJU / LSTCJA / LSTCTU / LSTCTA right for your machine?

Standard single-pair naval shipboard thermocouple drop cable for connecting individual engine, reduction-gear, chilled-water, HVAC and magazine temperature probes to local junction boxes.

Offshore platform & shipboard deck trays

Suitable

Installed throughout naval surface ships for individual Type J (exhaust/machinery) and Type T (refrigeration/cryo/ambient) probes.

Switchgear & control cabinet wiring

Suitable

Compact 5.6–7.4 mm outer diameter routes easily into shipboard temperature scanners and local transmitter housings.

Fixed installation

Suitable

LSTCJA and LSTCTA variants include braided Aluminum alloy 5056 armour for exposed machinery spaces.

Energy chain / drag chain

Not suitable

Fixed shipboard installation cable; not for continuous flexing drag chains.

Use PUR-HF Drag-Chain Cable
Typical machinesNaval Propulsion & Auxiliary Machinery RoomsShipboard Chilled-Water, HVAC & Galley Cold StoresAmmunition Magazine Temperature MonitoringMarine Diesel & Gas Turbine Bearing SensorsCoast Guard & Commercial Marine Retrofits

Construction

Layer by layer

MIL-DTL-24643/55 (LSTCJU / LSTCJA / LSTCTU / LSTCTA) showing 1 twisted pair of 20 AWG stranded Type J or Type T alloy conductors, XLPO primary insulation, halogen-free binder, LSZH outer jacket, and optional braided aluminium armour (A).

1234
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
120 AWG stranded Type J or Type T thermocouple pair7-strand 20 AWG (0.52 mm²) Iron/Constantan (LSTCJU/A) or Copper/Constantan (LSTCTU/A) per ASTM E230True thermocouple-grade EMF tolerance over shipboard ambient swings
2Cross-linked polyolefin (XLPO) core insulationHalogen-free radiation-cross-linked polyolefin (Type J: White+/Red-; Type T: Blue+/Red-)300 V rms working voltage, +105 °C continuous rating
3Low-Smoke Zero-Halogen (LSZH) cross-linked outer jacketFlame-retardant naval cross-linked polyolefin outer sheath (Unarmoured on LSTCJU / LSTCTU)IEEE 1202 flame retardant with < 0.2 % halogen content
4Braided Aluminum 5056 armour (LSTCJA / LSTCTA only)External braided Aluminum alloy 5056 wire armour applied over the LSZH jacket on '-A' variantsProvides shipboard cut, crush and rodent protection

LSTCJU (M24643/55-01UN) · Type J Unarmoured

1 Pair × 20 AWG Iron/Constantan (Type J) unarmoured low-smoke shipboard cable

LSTCJA (M24643/55-01AN) · Type J Armoured

1 Pair × 20 AWG Iron/Constantan (Type J) aluminium-braid armoured shipboard cable

LSTCTU / LSTCTA (M24643/55-02UN / -02AN)

1 Pair × 20 AWG Copper/Constantan (Type T) unarmoured or aluminium-braid armoured cable

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on MIL-DTL-24643/55 (M24643/55) / ASTM E230. Values for your order are confirmed in the datasheet and quotation.

Electrical

Thermocouple calibrations
Type J (Fe/CuNi, 50.4 µV/°C) · Type T (Cu/CuNi, 38.7 µV/°C)
Loop resistance @ 20 °C
1.17 Ω/m (Type J 20 AWG) · 0.98 Ω/m (Type T 20 AWG)
Voltage & dielectric test
300 V rms working · 1,500 V AC rms for 1 min
Insulation resistance
≥ 1,000 MΩ·1000 ft (≥ 305 MΩ·km) @ 500 V DC

Thermal

Cable operating temp.
-30 °C to +105 °C continuous shipboard service
Type J / T EMF accuracy
Type J: ±2.2 °C (±1.1 °C Spec) · Type T: ±1.0 °C (±0.5 °C Spec)
Cold bend performance
-30 °C cold mandrel bend test without cracking

Mechanical

Min. bend radius
6 × OD (LSTCJU / LSTCTU) · 8 × OD (LSTCJA / LSTCTA)
Conductor stranding
7 strands × 28 AWG (nominal 20 AWG / 0.52 mm²)
Armour coverage (-A)
≥ 80 % Aluminum alloy 5056 external wire braid

Resistance

Flame & smoke
IEEE 1202 vertical tray flame & MIL-DTL-24643 low smoke
Zero halogen / acid gas
Halogen content < 0.2 %, acid gas evolution < 2.0 %
Marine fluid resistance
Resistant to NATO F-76 diesel, JP-5 jet fuel & lube oil

Reference standards

Military specification
MIL-DTL-24643/55 (M24643/55-01UN/AN & -02UN/AN)
Thermocouple standard
ASTM E230 / ANSI MC96.1
RoHS & REACH
2011/65/EU & EC 1907/2006 compliant

Identification

Core colour code
Type J: White (+) / Red (-) · Type T: Blue (+) / Red (-)
Type designations
LSTCJU (J-Unarm), LSTCJA (J-Arm), LSTCTU (T-Unarm), LSTCTA (T-Arm)
Customs tariff (HS)
8544.4993

Sizes

4 standard MIL-DTL-24643/55 (LSTCJU / LSTCJA / LSTCTU / LSTCTA) configurations

Military part numbers, thermocouple calibrations, outer diameters and weights.

Dimensions & M24643/55 part numbers
Type & military PINTC calibration & armourNominal Ø
mm		Weight ≈
kg/km		TC loop R
Ω/m		Min. bend R
mm		Enquiry
MIL-DTL-24643/55 Single-Pair Shipboard Thermocouple Cables
LSTCJU (M24643/55-01UN)Type J (Fe/CuNi) · 1P×20 AWG · Unarmoured5.8481.1735
LSTCJA (M24643/55-01AN)Type J (Fe/CuNi) · 1P×20 AWG · Al-Armoured7.1741.1757
LSTCTU (M24643/55-02UN)Type T (Cu/CuNi) · 1P×20 AWG · Unarmoured5.8490.9835
LSTCTA (M24643/55-02AN)Type T (Cu/CuNi) · 1P×20 AWG · Al-Armoured7.1750.9857
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • For watertight cross-linked single-pair Type J, K, T shipboard cables with water-blocking filler, see MIL-DTL-24643/56 (LSTCJX / LSTCKX / LSTCTX).

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

  1. ConductorClass 5 stranding
  2. Spark test100 % in-line
  3. Lay-upCores, earth, fillers
  4. SheathingInner, braid / screen, outer
  5. Electrical testsAC voltage, resistance
  6. DimensionsOD, wall thickness
  7. Inspection documents & dispatchDrum & dispatch
Testing & inspectionTest value / referenceFrequency
Routine tests
100 % ASTM E230 Seebeck EMF test, 1.5 kV AC dielectric & IR checkType J / Type T EMF within ASTM E230 limits and zero dielectric breakdownEvery manufactured reel
Sample tests
Cold bend (-30 °C) & hot oil immersion testZero jacket cracking and ≥ 75 % tensile/elongation retentionPer production lot
IEEE 1202 vertical tray flame, smoke density & acid gas testPasses naval low-smoke zero-halogen fire qualificationQualification test

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

MIL-DTL-24643/55 CompliantASTM E230 Type J & Type TIEEE 1202 Naval Low-Smoke

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX M24643/55-01UN LSTCJU 1P20AWG TYPE J LOW SMOKE
Delivery form
Fumigated wooden drums, steel reels or precision spools
Standard lengths
500 m · 1000 m (or custom cut/spooled lengths)
MOQ
100 m (standard) · 500 m (custom)
Lead time
2–4 weeks ex-works
Incoterms
EXW, FOB, CIF, DAP

Technical documents

Downloads

PDFLSTCJU / LSTCJA / LSTCTU / LSTCTA MIL-DTL-24643 LSTCJU / LSTCJA / – technical datasheet4 sizes · construction, technical data, approvalsXLSXLSTCJU / LSTCJA / LSTCTU / LSTCTA spec data (Excel)All 4 sizes with dimensions and data, for your BOM or quotation
Revision
2026-10-20
Updated
2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

How do the four MIL-DTL-24643/55 type codes (LSTCJU, LSTCJA, LSTCTU, LSTCTA) break down?
'LS' = Low Smoke zero-halogen; 'TC' = Thermocouple; 'J' or 'T' = ASTM E230 Thermocouple calibration (Type J Iron/Constantan or Type T Copper/Constantan); and the final letter 'U' = Unarmoured (-UN) or 'A' = Aluminum-braid Armoured (-AN).
Why is Type T (LSTCTU / LSTCTA) specified alongside Type J on naval vessels?
Type T (Copper / Constantan) uses a pure copper positive leg and a corrosion-resistant Constantan negative leg, offering ±0.5 °C to ±1.0 °C accuracy and zero rust risk in damp refrigeration, chilled-water, air-conditioning and ammunition magazine monitoring.
When is MIL-DTL-24643/56 (LSTCJX / LSTCKX / LSTCTX) required instead of MIL-DTL-24643/55?
MIL-DTL-24643/55 (LSTCJU/T) is non-watertight for dry internal compartments. When the cable passes through watertight bulkheads, weather decks or bilge zones—or when Type K (Chromel/Alumel) calibration is needed—specify watertight MIL-DTL-24643/56 (LSTCJX / LSTCKX / LSTCTX).
Can we order multi-pair Type J shipboard thermocouple cables?
Yes. For 2, 3 or 4 shielded pairs of 20 AWG Type J in a single cable, specify MIL-DTL-24643/42 (LS2SJ, LS3SJ, LS4SJ).

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