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Product

IEC 61515 / ASTM E585 MIMS cableIEC 61515 & ASTM E585Type K, N, J, T, E · Class 1MgO ≥ 99.4 % · Up to +1250 °C

Mineral-Insulated Thermocouple CableMgO-compacted metal-sheathed (MIMS) thermocouple cable up to +1250 °C

High-integrity Mineral-Insulated Metal-Sheathed (MIMS) thermocouple cable built to IEC 61515 and ASTM E585 with Class 1 Type K, N, J, T or E conductors compacted in high-purity MgO (≥ 99.4 %) inside a seamless Alloy 600, AISI 310, 316L or NiCrSi sheath.

Flame-retardant
Low-EMC design
EMC screen
Oil-resistant
Order designation
MI-K-1P-6.0-A600
Sheath OD
6.0 mm
Nominal wall
0.72 mm
Conductor Ø ≈
1.02 mm
Weight ≈
220.0 kg/km
All sizes (16)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Calibrations
K, N, J, T, E
Simplex (1P), Duplex (2P) & 3P
Max. temp.
Up to +1250 °C
Alloy 600 / AISI 310 / NiCrSi
Insulation
Compacted MgO
≥ 99.4 % purity (or nuclear 99.7%)
Sheath Ø (OD)
0.5 to 8.0 mm
wall thickness ≥ 10–12 % of OD
Bend radius
2 × OD (min.)
formable without losing IR
Pressure rating
Up to 400 MPa
hermetic seamless drawn tube

Typical values for this cable type, based on IEC 61515 / ASTM E585 / AMS 2750 — confirmed in the datasheet and quotation for your order.

Application fit

Is Mineral-Insulated Thermocouple Cable right for your machine?

Engineered both as primary raw stock for manufacturing industrial mineral-insulated thermocouple probes and for direct high-temperature, high-pressure routing inside furnaces, reactors, turbines and nuclear vessels where polymer insulation would char or melt.

Fixed installation

Suitable

Can be formed around tight 2 × OD bends and routed directly through +1250 °C furnace zones, steam headers and pressure vessels.

Offshore platform & shipboard deck trays

Suitable

Seamless corrosion-resistant Alloy 600, AISI 316L or AISI 310 metallic sheath is 100 % hermetic against moisture, steam and corrosive gases.

TBM gantry & advancing tunnel reel

Suitable

Solid compacted MgO and seamless stainless/nickel-alloy tube withstand extreme mechanical crush and hydrostatic pressure.

Energy chain / drag chain

Not suitable

Work-hardening metallic tube is designed for static forming and high-vibration engines, not repetitive drag chains.

PUR Drag-Chain Control Cable
Typical machinesAMS 2750 Aerospace Heat-Treatment & Vacuum FurnacesPetrochemical Steam Crackers, Reformers & HydrocrackersGas Turbines, Jet Engines & Exhaust Gas Path TestingNuclear Reactors, Pressurisers & Superheated SteamThermocouple Probe & Sensor OEM Manufacturing

Construction

Layer by layer

Shown: MI-K-1P-6.0-A600 (IEC 61515) 6.0 mm OD simplex Type K cable with 1.02 mm solid NiCr (+) and NiAl (−) conductors, high-density compacted MgO powder and 0.72 mm wall seamless Alloy 600 (NiCr15Fe) sheath.

123
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Solid Class 1 thermocouple alloy conductorsSimplex (2-wire), Duplex (4-wire) or Triplex (6-wire) Type K (NiCr/NiAl), Type N (NiCrSi/NiSi), Type J (Fe/CuNi), Type T (Cu/CuNi) or Type E (NiCr/CuNi)Uniform wire diameter (≈ 17 % of OD on simplex, 13 % on duplex) maintained concentric during multi-pass cold drawing
2High-density compacted Magnesium Oxide (MgO)Refractory MgO dielectric powder (≥ 99.4 % purity, low Fe₂O₃/B₂O₃/SiO₂ impurity content) compacted to > 75 % theoretical densityProvides ≥ 1,000 MΩ·m insulation resistance at 20 °C, high thermal conductivity for fast probe response, and zero outgassing to +1250 °C
3Seamless cold-drawn & bright-annealed metallic sheathAlloy 600 (NiCr15Fe, UNS N06600), NiCrSi sheath alloy, AISI 310 (25Cr-20Ni), AISI 316L (UNS S31603) or AISI 321 (nominal wall 10–12 % of OD)Forms a hermetic, pressure-tight, EMI-shielded metallic barrier that can be TIG/laser welded or brazed into process fittings

Alloy 600 Sheath (UNS N06600 · to +1150 °C)

72Ni-15Cr-8Fe superalloy resisting oxidation, chloride SCC and carburisation ( avoid sulphur > +550 °C)

NiCrSi Sheath for Type N (to +1250 °C)

Matched Nicrosil-type Cr-Si-Ni sheath eliminating Ni/Cr vapour cross-contamination of Type N conductors

AISI 310 / AISI 316L Stainless Sheath

AISI 310 (25Cr-20Ni) for sulphurous furnace gases to +1100 °C; AISI 316L for chemical & food process to +850 °C

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on IEC 61515 / ASTM E585 / AMS 2750. Values for your order are confirmed in the datasheet and quotation.

Electrical

Thermocouple calibrations
Type K, N, J, T, E (IEC 60584-1 Class 1 standard; Class 2 optional)
Conductor configurations
Simplex (1P / 2-wire), Duplex (2P / 4-wire), Triplex (3P / 6-wire)
Insulation resistance @ 20 °C
≥ 1,000 MΩ·m (1 GΩ·m) at 500 V DC (≥ 100 V DC for OD < 1.5 mm)
Insulation resistance @ +1000 °C
≥ 0.5 MΩ·m (Type K / N high-purity MgO ≥ 99.4 %)
Dielectric withstand voltage
500 V rms AC (1.0–1.5 mm OD) · 1,000 V rms AC (≥ 2.0 mm OD) for 1 min

Thermal

Alloy 600 (NiCr15Fe / UNS N06600)
Max. continuous +1150 °C (oxidising/inert/vacuum; avoid S > +550 °C)
NiCrSi-type high-temp sheath
Max. continuous +1250 °C (matched thermal expansion & chemistry for Type N)
AISI 310 (25Cr-20Ni / 1.4841)
Max. continuous +1100 °C (resists oxidising & sulphurous combustion gases)
AISI 316L (17Cr-12Ni-2Mo / 1.4404)
Max. continuous +850 °C (chemical, pharma, marine & food service)

Mechanical

Standard outer diameters (OD)
0.50, 1.0, 1.5, 2.0, 3.0, 4.5, 6.0, 8.0 mm (and 1/16" to 1/4")
Nominal sheath wall thickness
10 % to 12 % of cable OD (minimum ≥ 8 % of OD)
Nominal conductor diameter
Simplex: ≈ 17 % of OD · Duplex: ≈ 13 % of OD
Minimum bend radius
2 × OD around mandrel without sheath cracking or IR loss

Reference standards

Primary MIMS cable standards
IEC 61515, ASTM E585 / E585M & ASTM E608
Pyrometry & calibration standards
IEC 60584-1 Class 1, ANSI/ISA MC96.1 Special Limits & AMS 2750

Identification

Coil / spool delivery
Bright-annealed moisture-sealed coils with brazed/resin-sealed ends
Traceability
Heat/lot number, EMF calibration certificate at test points, and PMI report
Customs tariff (HS)
8544.49 / 9033.00

Sizes

16 standard IEC 61515 MIMS thermocouple cable sizes

Simplex (2-wire) and Duplex (4-wire) Type K, N, J, T and E in Alloy 600, NiCrSi, AISI 310 and AISI 316L sheaths.

Dimensions, wall thickness & weights
Order designationType & polesSheath alloySheath OD
mm		Wall nom.
mm		Wire Ø
mm ≈		Weight ≈
kg/km		Max. sheath
temp.		Enquiry
Type K (NiCr / NiAl) Class 1 — Alloy 600 & AISI 310 Sheath
MI-K-1P-1.0-A600Type K · Simplex (2-core)Alloy 600 (NiCr15Fe)1.00.120.176.2+1100 °C
MI-K-1P-1.5-A600Type K · Simplex (2-core)Alloy 600 (NiCr15Fe)1.50.180.2613.8+1100 °C
MI-K-1P-3.0-A600Type K · Simplex (2-core)Alloy 600 (NiCr15Fe)3.00.360.5155.0+1150 °C
MI-K-1P-4.5-A600Type K · Simplex (2-core)Alloy 600 (NiCr15Fe)4.50.540.77124.0+1150 °C
MI-K-1P-6.0-A600Type K · Simplex (2-core)Alloy 600 (NiCr15Fe)6.00.721.02220.0+1150 °C
MI-K-2P-3.0-A600Type K · Duplex (4-core)Alloy 600 (NiCr15Fe)3.00.360.3957.0+1150 °C
MI-K-2P-6.0-A600Type K · Duplex (4-core)Alloy 600 (NiCr15Fe)6.00.720.78228.0+1150 °C
MI-K-1P-6.0-SS310Type K · Simplex (2-core)AISI 310 (25Cr-20Ni)6.00.721.02216.0+1100 °C
Type N (NiCrSi / NiSi) Class 1 — Alloy 600 & NiCrSi Sheath (to +1250 °C)
MI-N-1P-3.0-A600Type N · Simplex (2-core)Alloy 600 (NiCr15Fe)3.00.360.5155.0+1150 °C
MI-N-1P-4.5-A600Type N · Simplex (2-core)Alloy 600 (NiCr15Fe)4.50.540.77124.0+1200 °C
MI-N-1P-6.0-NiCrSiType N · Simplex (2-core)NiCrSi-type sheath6.00.721.02222.0+1250 °C
MI-N-2P-6.0-NiCrSiType N · Duplex (4-core)NiCrSi-type sheath6.00.720.78230.0+1250 °C
Type J, T & E Class 1 — AISI 316L Stainless Steel Sheath
MI-J-1P-3.0-SS316LType J · Simplex (2-core)AISI 316L Stainless3.00.360.5154.0+750 °C
MI-J-1P-6.0-SS316LType J · Simplex (2-core)AISI 316L Stainless6.00.721.02215.0+750 °C
MI-T-1P-3.0-SS316LType T · Simplex (2-core)AISI 316L Stainless3.00.360.5154.0+400 °C
MI-E-1P-3.0-SS316LType E · Simplex (2-core)AISI 316L Stainless3.00.360.5154.0+850 °C
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • Custom diameters from 0.25 mm to 10.8 mm and heavy-wall (15 % OD) petrochemical grades are manufactured to order.

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
Insulation resistance (IR) & AC dielectric test (IEC 61515)IR ≥ 1,000 MΩ·m at 20 °C (500 V DC); AC dielectric test without breakdownEvery manufactured coil
Multi-point thermoelectric EMF calibration & sheath ductility testIEC 60584-1 Class 1 EMF tolerance; 2 × OD mandrel bend & helium/dye-penetrant sheath checkEvery production lot

Inspection certificate

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

Product approvals

IEC 61515 & ASTM E585 CertifiedIEC 60584-1 Class 1 & AMS 2750 CompliantEN 10204 3.1 Material & Calibration Cert.

Company certificates

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

Marking & supply

Ordering & delivery

Sheath marking

Tagged Stainless Spool / Coil: TEBAOFLEX MI-<type>-<OD>-<sheath> IEC 61515 CLASS 1 LOT#
Delivery form
Non-returnable fumigated wooden drums
Standard lengths
500 m · 1000 m standard drums (cut lengths on request)
MOQ
500 m (stock sizes) · 1000 m (custom)
Lead time
2–4 weeks ex-works
Incoterms
EXW, FCA, FOB, CIF, DAP

Technical documents

Downloads

PDFMineral-Insulated Thermocouple Cable – technical datasheet16 sizes · construction, technical data, approvalsXLSXMineral-Insulated Thermocouple Cable spec data (Excel)All 16 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.

Why must mineral-insulated (MIMS) thermocouple cable ends be sealed immediately after cutting?
Compacted Magnesium Oxide (MgO) powder is strongly hygroscopic and absorbs atmospheric moisture within minutes of exposure. Absorbed moisture lowers the insulation resistance below the IEC 61515 1,000 MΩ·m minimum and causes shunting errors at high temperature. If moisture enters a cut end, bake the cable end at +150…+250 °C before potting with epoxy or ceramic cement.
Why is a NiCrSi-type sheath preferred over Alloy 600 or stainless steel for Type N above +1100 °C?
Above +1100 °C, Manganese and Chromium vapour diffusing from a standard stainless steel sheath can contaminate the thermocouple conductors inside the MgO, causing progressive EMF drift. A NiCrSi-type sheath matches the chemical composition and thermal expansion coefficient of the Type N (NiCrSi/NiSi) conductors, enabling stable operation up to +1250 °C.
Can MIMS thermocouple cable be bent in the field?
Yes. Because the seamless metallic sheath is supplied in the bright-annealed condition and the MgO powder is compacted to high density, the cable can be cold-formed around a minimum bend radius of 2 × OD (e.g. a 12 mm radius for a 6.0 mm OD cable) without shorting the internal conductors.
How should the screen and drain wire of Mineral-Insulated Thermocouple Cable be earthed in instrumentation and Ex-i loops?
To prevent circulating 50/60 Hz ground-loop currents from coupling into millivolt or 4–20 mA signals, the Al/PET screen and tinned copper drain wire of Mineral-Insulated Thermocouple Cable should be bonded to the clean instrumentation earth bar at one end only (typically in the control/marshalling cabinet) and insulated against chassis contact at the field transmitter or junction box, in accordance with IEC 60079-14 and EN 50288-7.

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