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Product

instrumentation cable seriesMIL-DTL-24643/56 WatertightType J, Type K & Type TBulkhead Pressure Blocked

LSTCJX / LSTCKX / LSTCTX MIL-DTL-24643 LSTCJX / LSTCKX / LSTCTXMIL-DTL-24643/56 watertight low-smoke Type J, K & T shipboard thermocouple cable

MIL-DTL-24643/56 (LSTCJX, LSTCKX, LSTCTX) Watertight Cross-Linked Naval Shipboard Thermocouple Cable with a water-blocked 20 AWG Type J, Type K or Type T twisted pair, overall tinned copper shield, longitudinally watertight filler.

Watertight Longitudinal Block
MIL-DTL-24643/56
Shielded Twisted Pair
Naval Low-Smoke LSZH
Order designation
LSTCKX (M24643/56-02UN)
Nominal outer Ø
7.4 mm
Weight ≈
84 kg/km
TC loop R
1.90 Ω/m
Min. bend radius
44 mm
All sizes (6)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Military spec
M24643/56
LSTCJX / LSTCKX / LSTCTX
Calibrations
Type J, K & T
Fe/CuNi · NiCr/NiAl · Cu/CuNi
Watertightness
Watertight Block
Passes MIL-DTL-24643 water head
Conductor
1 Pair × 20 AWG
7-strand water-blocked alloys
EMC shield
Tinned Cu braid
Overall shield + drain/barrier
Temperature
-30 to +105 °C
Cross-linked polyolefin ('X')

Typical values for this cable type, based on MIL-DTL-24643/56 (M24643/56) / ASTM E230 — confirmed in the datasheet and quotation for your order.

Application fit

Is LSTCJX / LSTCKX / LSTCTX right for your machine?

Required whenever naval shipboard thermocouple runs penetrate watertight bulkheads, weather decks, bilge compartments or gas-turbine modules where longitudinal water hosing through the cable core must be prevented.

Immersion & wet locations

Suitable

Elastomeric water-blocking compound seals strand and core interstices to pass MIL-DTL-24643 hydrostatic pressure tests.

Offshore platform & shipboard deck trays

Suitable

Includes LSTCKX (Type K Chromel/Alumel) for LM2500/MT30 marine gas-turbine exhaust gas temperature (EGT) harnesses.

Switchgear & control cabinet wiring

Suitable

Available in Unarmoured (-UN) and braided Aluminum-Armoured (-AN) configurations for watertight stuffing tubes.

Energy chain / drag chain

Not suitable

Fixed naval watertight bulkhead cable; not for continuous flexing drag chains.

Use PUR-HF Drag-Chain Cable
Typical machinesMarine Gas Turbine EGT & Enclosure Monitoring (Type K)Watertight Bulkhead & Damage-Control ZonesSubmarine & Surface Combatant Propulsion RoomsBilge, Ballast & Weather-Deck Sensor DropsShipboard Cryogenic & Chilled-Water Loops (Type T)

Construction

Layer by layer

MIL-DTL-24643/56 (LSTCJX / LSTCKX / LSTCTX) showing water-blocked 7-strand 20 AWG Type J, K or T thermocouple pair, cross-linked polyolefin (XLPO) insulation, longitudinal water-blocking matrix, tinned copper braid screen, and watertight LSZH outer jacket.

12345
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Water-blocked 20 AWG Type J, K or T stranded pair7-strand 20 AWG (0.52 mm²) Iron/Constantan (J), Chromel/Alumel (K) or Copper/Constantan (T) with strand water-blocking compoundPrevents capillary seawater wicking along the 7-wire strands
2Cross-linked polyolefin ('X') primary insulationHalogen-free radiation-cross-linked polyolefin (J: White/Red · K: Yellow/Red · T: Blue/Red per ASTM E230)Rated 300 V rms and +105 °C continuous shipboard ambient
3Longitudinal water-blocking filler & binderNon-hygroscopic water-blocking elastomeric filler and swellable/barrier tape filling all pair valleysPasses MIL-DTL-24643 longitudinal hydrostatic water-tightness test
4Overall tinned copper wire braid shield≥ 85 % optical coverage tinned copper braid screen over the water-blocked coreProtects millivolt thermocouple signals from shipboard radar/power EMI
5Watertight Low-Smoke Zero-Halogen (LSZH) outer jacketPressure-extruded cross-linked polyolefin LSZH jacket (plus optional Aluminum alloy 5056 braid armour on -AN)Smooth circular profile for naval multi-cable transit (MCT) & stuffing tubes

LSTCJX (M24643/56-01UN / -01AN) · Type J

Watertight 1P × 20 AWG Type J (Iron/Constantan) shielded shipboard thermocouple cable

LSTCKX (M24643/56-02UN / -02AN) · Type K

Watertight 1P × 20 AWG Type K (Chromel/Alumel) shielded shipboard gas-turbine TC cable

LSTCTX (M24643/56-03UN / -03AN) · Type T

Watertight 1P × 20 AWG Type T (Copper/Constantan) shielded shipboard thermocouple cable

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on MIL-DTL-24643/56 (M24643/56) / ASTM E230. Values for your order are confirmed in the datasheet and quotation.

Electrical

Thermocouple calibrations
Type J (Fe/CuNi) · Type K (NiCr/NiAl) · Type T (Cu/CuNi)
Loop resistance @ 20 °C
1.17 Ω/m (Type J) · 1.90 Ω/m (Type K) · 0.98 Ω/m (Type T)
Voltage & dielectric test
300 V rms working · 1,500 V AC rms dielectric test
Insulation resistance
≥ 1,000 MΩ·1000 ft (≥ 305 MΩ·km) @ 500 V DC

Thermal

Cable continuous rating
-30 °C to +105 °C shipboard ambient
EMF tolerance
ASTM E230 Standard (±2.2 °C J/K, ±1.0 °C T) or Special limits
Cold bend test
-30 °C mandrel bend without cracking

Mechanical

Min. bend radius
6 × OD (-UN unarmoured) · 8 × OD (-AN Al-armoured)
Watertight hydrostatic test
Zero axial leakage under MIL-DTL-24643 differential pressure
Shield coverage
≥ 85 % tinned copper wire braid screen

Resistance

Flame propagation
IEEE 1202 / UL 1581 vertical tray flame test
Smoke & halogen content
Low-smoke optical density, < 0.2 % halogens, < 2 % acid gas
Oil & seawater resistance
Resistant to naval fuel, synthetic turbine oil & seawater

Reference standards

Military specification
MIL-DTL-24643/56 (M24643/56-01, -02, -03 UN/AN)
Thermocouple standard
ASTM E230 / ANSI MC96.1
RoHS & REACH
2011/65/EU & EC 1907/2006 compliant

Identification

ANSI MC96.1 core colours
J: White(+)/Red(-) · K: Yellow(+)/Red(-) · T: Blue(+)/Red(-)
Military PINs
M24643/56-01 (LSTCJX), -02 (LSTCKX), -03 (LSTCTX)
Customs tariff (HS)
8544.4993

Sizes

6 standard MIL-DTL-24643/56 (LSTCJX / LSTCKX / LSTCTX) configurations

Watertight unarmoured (-UN) and aluminium-armoured (-AN) shipboard thermocouple cables.

Dimensions & M24643/56 part numbers
Type & military PINTC calibration & armourNominal Ø
mm		Weight ≈
kg/km		TC loop R
Ω/m		Min. bend R
mm		Enquiry
MIL-DTL-24643/56 Watertight Shielded Shipboard Thermocouple Cables
LSTCJX (M24643/56-01UN)Type J (Fe/CuNi) · Watertight Unarmoured7.4821.1744
LSTCJXA (M24643/56-01AN)Type J (Fe/CuNi) · Watertight Al-Armoured8.61121.1769
LSTCKX (M24643/56-02UN)Type K (NiCr/NiAl) · Watertight Unarmoured7.4841.9044
LSTCKXA (M24643/56-02AN)Type K (NiCr/NiAl) · Watertight Al-Armoured8.61141.9069
LSTCTX (M24643/56-03UN)Type T (Cu/CuNi) · Watertight Unarmoured7.4830.9844
LSTCTXA (M24643/56-03AN)Type T (Cu/CuNi) · Watertight Al-Armoured8.61130.9869
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • LSTCKX (M24643/56-02) is the sole MIL-DTL-24643 single-pair Type K shipboard thermocouple cable for marine gas turbines.

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 EMF calibration, 1.5 kV AC dielectric & IR testType J, K or T EMF within ASTM E230 limits and zero breakdownEvery manufactured reel
Sample tests
MIL-DTL-24643 longitudinal hydrostatic watertightness testZero water leakage through conductor strands or core intersticesQualification & lot sample
IEEE 1202 vertical flame, smoke density & halogen content testPasses naval shipboard LSZH fire safety criteriaQualification test

Inspection certificate

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

Product approvals

MIL-DTL-24643/56 WatertightASTM E230 Type J / K / TIEEE 1202 Naval Low-Smoke

Company certificates

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

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX M24643/56-02UN LSTCKX 1P20AWG TYPE K WATERTIGHT
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

PDFLSTCJX / LSTCKX / LSTCTX MIL-DTL-24643 LSTCJX / LSTCKX / LSTCTX – technical datasheet6 sizes · construction, technical data, approvalsXLSXLSTCJX / LSTCKX / LSTCTX spec data (Excel)All 6 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.

What are the three key differences between MIL-DTL-24643/56 (LSTCJX/KX/TX) and MIL-DTL-24643/55 (LSTCJU/TU)?
First, M24643/56 is longitudinally watertight (blocked strands and core) to prevent flooding across watertight bulkheads. Second, M24643/56 includes an overall tinned-copper braid EMC shield. Third, M24643/56 adds Type K (Chromel/Alumel, LSTCKX) alongside Type J and Type T.
Why is LSTCKX (M24643/56-02) standard on naval gas-turbine propulsion modules?
Marine gas turbines (such as GE LM2500 and Rolls-Royce MT30) measure exhaust gas and power-turbine inlet temperatures up to +850–1,000 °C using Type K (NiCr/NiAl) probes, requiring a matched Type K watertight shielded extension cable (LSTCKX) through the acoustic module boundary.
What does the trailing 'X' in LSTCJX, LSTCKX and LSTCTX indicate?
In MIL-DTL-24643 nomenclature for this series, 'X' denotes cross-linked polyolefin insulation in a watertight ('W' test qualified) shielded construction.
Are both unarmoured (-UN) and aluminium-braid armoured (-AN) versions stocked?
Yes. Both -01UN/-02UN/-03UN and -01AN/-02AN/-03AN are supplied with full military lot test reports.

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