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Product

High-temperature wireASTM E595 UHV (10⁻¹⁰ mbar)Ag-Cu Braid Screen-269 °C to +250 °C

301-KAPM-PAIR Polyimide UHV Screened Twisted-Pair Wire10⁻¹⁰ mbar UHV silver-copper-braid screened polyimide twisted-pair wire (-269 to +250 °C)

301-KAPM-PAIR ultra-high-vacuum (UHV) screened twisted-pair cable featuring multistrand silver-plated OFHC copper cores, thin-wall aromatic polyimide insulation, and a braided silver-plated copper EMC shield for 10⁻¹⁰ mbar and 4 K to +250 °C.

EMC screen
Low-EMC design
Approved
Flame-retardant
Order designation
301-KAPM-PAIR (1×2×28 AWG)
Outer Ø ≈
1.40 mm
Wall thickness
0.07 mm
Total weight ≈
5.2 kg/km
Min. bend R (fixed)
7 mm
All sizes (8)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Vacuum rating
10⁻¹⁰ mbar UHV
ASTM E595 TML < 1 % certified
Temperature
-269…+250 °C
4 K cryostat to +250 °C bake
Rated voltage
300 V / 500 V DC
1500 V AC dielectric test
Conductor
Ag-Cu stranded
19-strand flexible Ag-OFC
EMC shield
Ag-Cu braid
≥ 85 % UHV-vented braid screen
Pair configs
1, 2 or 4 pairs
28 to 22 AWG (0.09–0.35 mm²)

Typical values for this cable type, based on ASTM E595 UHV Outgassing / MIL-DTL-81381 — confirmed in the datasheet and quotation for your order.

Application fit

Is 301-KAPM-PAIR right for your machine?

Select 301-KAPM-PAIR for low-level differential sensors, encoders, stepper motors, and piezo actuators inside UHV chambers where both electromagnetic shielding and flexible multistrand routing are required.

Switchgear & control cabinet wiring

Suitable

Twisted-pair lay plus ≥ 85 % silver-plated copper braid rejects common-mode magnetic and RF pickup on microvolt UHV sensor lines.

Furnace, kiln & high-temp zone

Suitable

Survives repeated +250 °C UHV chamber bakeouts with zero silicone or plasticiser outgassing.

Fixed installation

Suitable

19-strand flexible conductors accommodate in-vacuum 6-axis goniometer and sample manipulator motion from 4 K to +250 °C.

Motorised monospiral reel

Not suitable

Precision UHV instrument cable is designed for in-vacuum chambers and cryostats, not heavy outdoor drum reeling.

Use SiHFC for industrial plant EMC
Typical machinesSynchrotron Goniometers & StagesUHV Scanning Probe MicroscopySemiconductor E-Beam LithographyCryogenic Quantum & Detector ReadoutAerospace & Satellite Vacuum Harnesses

Construction

Layer by layer

301-KAPM-PAIR UHV construction: twisted pair of 19-strand silver-plated OFHC copper cores with polyimide film insulation and an outer braided silver-plated copper EMC shield.

1234
Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Multistrand silver-plated OFHC copper19-strand flexible silver-plated oxygen-free copper (19×0.07 mm to 19×0.15 mm)High flex life for in-vacuum XYZ translation stages and goniometers
2Thin-wall polyimide film (KAPM)Heat-sealed aromatic polyimide film on each core (amber / colour-coded)High dielectric breakdown (≥ 150 kV/mm) with minimal outgassing surface area
3Silver-plated copper EMC braidWoven silver-plated OFHC copper wire braid (≥ 85 % coverage)Provides 360° electrostatic and RF shielding while allowing rapid gas pump-out
4Optional open-spiral polyimide wrapOpen-helical or vented polyimide binding tape (on '-J' insulated screen variants)Isolates the outer braid electrically from chamber walls without trapping gas

301-KAPM-PAIR (Bare Ag-Cu Screen)

Exposed silver-plated copper braid outer screen for fastest UHV pump-down and lowest outgassing

301-KAPM-PAIR-J (Polyimide Wrapped)

With outer vented polyimide tape wrap isolating the silver-plated copper braid from grounded walls

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on ASTM E595 UHV Outgassing / MIL-DTL-81381. Values for your order are confirmed in the datasheet and quotation.

Electrical

Rated voltage
300 V AC / 500 V DC
Dielectric test voltage
1500 V AC core-to-core & core-to-screen
Max. current in UHV (20 °C)
1.5 A (28 AWG) · 3.0 A (24 AWG) · 4.5 A (22 AWG)
Mutual capacitance (1 kHz)
≈ 85 pF/m core-to-core · 145 pF/m core/screen

Thermal

Operating temperature range
-269 °C (4 K) to +250 °C
UHV bakeout temperature
+250 °C continuous bakeout
Cryogenic thermal cycling
Stable from 4 K liquid helium to +250 °C

Mechanical

Conductor stranding
19×0.07 mm (28 AWG) to 19×0.15 mm (22 AWG)
Pair twist lay length
20 to 25 mm precision symmetrical twist
Min. bending radius
5 × OD static · 10 × OD in-vacuum motion

Resistance

Vacuum outgassing (ASTM E595)
TML < 1.0 %, CVCM < 0.05 % (UHV < 10⁻¹⁰ mbar)
Radiation resistance
10⁷ Gy (10 MGy) ionizing radiation
Non-magnetic construction
100 % non-magnetic Ag-OFC (no nickel)

Reference standards

UHV outgassing standard
ASTM E595 / ECSS-Q-ST-70-02C
Core wire specification
MIL-DTL-81381 / NEMA WC 27500
RoHS & REACH
RoHS 3 & REACH compliant

Identification

Core identification
Amber + white/tracer polyimide pair
Package marking
TEBAOFLEX 301-KAPM-PAIR UHV 1E-10 MBAR
Customs tariff (HS)
8544.49

Sizes

8 standard configurations (301-KAPM-PAIR)

Engineering dimensions, conductor stranding, mass and electrical ratings for 301-KAPM-PAIR per ASTM E595 UHV Outgassing / MIL-DTL-81381.

Dimensions & weights
Order designationCross-section / sizeConductor buildWall ≈
mm		Outer Ø ≈
mm		Metal
kg/km		Weight ≈
kg/km		Min. bend R
fixed mm		Enquiry
Standard 301-KAPM-PAIR configurations
301-KAPM-PAIR (1×2×28 AWG)1×2×0.09 mm²19×0.07 mm Ag-OFC0.071.403.85.27
301-KAPM-PAIR-26 (1×2×26 AWG)1×2×0.15 mm²19×0.10 mm Ag-OFC0.081.705.47.59
301-KAPM-PAIR-24 (1×2×24 AWG)1×2×0.22 mm²19×0.12 mm Ag-OFC0.081.907.610.210
301-KAPM-PAIR-22 (1×2×22 AWG)1×2×0.35 mm²19×0.15 mm Ag-OFC0.092.3011.214.812
301-KAPM-PAIR-J (1×2×28 AWG Wrapped)1×2×0.09 mm²19×0.07 mm Ag-OFC0.121.603.86.08
301-KAPM-PAIR-24J (1×2×24 AWG Wrapped)1×2×0.22 mm²19×0.12 mm Ag-OFC0.132.107.611.411
301-KAPM-2PAIR (2×2×28 AWG)2×2×0.09 mm²19×0.07 mm Ag-OFC0.122.607.210.813
301-KAPM-4PAIR (4×2×28 AWG)4×2×0.09 mm²19×0.07 mm Ag-OFC0.143.4013.819.517
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • Outer diameters and weights are nominal engineering values for 301-KAPM-PAIR subject to standard manufacturing tolerances per ASTM E595 UHV Outgassing / MIL-DTL-81381.

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
Dielectric spark / high-voltage withstand test100 % in-line spark and AC/DC dielectric withstand per ASTM E595 UHV Outgassing / MIL-DTL-81381Every manufactured length
Conductor DC resistance & continuity checkWithin maximum 20 °C resistance limit specified for 301-KAPM-PAIREvery spool or drum length
Sample tests
Thermal ageing & dimensional verificationWall thickness, concentricity and post-ageing elongation per ASTM E595 UHV Outgassing / MIL-DTL-81381Per production batch
Flame, outgassing or high-temperature enduranceQualified to ASTM E595 UHV Outgassing / MIL-DTL-81381 thermal and environmental performance criteriaType qualification

Inspection certificate

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

Product approvals

ASTM E595 UHV Outgassing / MIL-DTL-81381CE (2014/35/EU) & RoHS 3 (2015/863/EU) CompliantREACH SVHC & Halogen/Asbestos Compliance Verified

Company certificates

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

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX 301-KAPM-PAIR 1×2×28AWG UHV 1E-10 MBAR
Delivery form
Precision spools, coils or export wooden drums
Standard lengths
50 m · 100 m · 500 m · 1000 m (or cut harnesses)
MOQ
100 m (stock sizes) · 300–500 m (custom build)
Lead time
2–4 weeks ex-works
Incoterms
EXW, FOB, CIF, DAP

Technical documents

Downloads

PDF301-KAPM-PAIR Polyimide UHV Screened Twisted-Pair Wire – technical datasheet8 sizes · construction, technical data, approvalsXLSX301-KAPM-PAIR spec data (Excel)All 8 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 does 301-KAPM-PAIR use silver-plated OFHC copper without a nickel underplate?
Many UHV experiments — including electron microscopes, ARPES spectrometers, and quantum sensors — prohibit ferromagnetic materials inside the vacuum chamber. Silver plated directly onto oxygen-free high-conductivity (OFHC) copper provides +250 °C bakeout stability while remaining 100 % non-magnetic.
Should I choose the bare silver-copper braid (301-KAPM-PAIR) or the polyimide-wrapped screen (301-KAPM-PAIR-J)?
Choose the bare silver-plated copper braid when fastest vacuum pump-down and minimum polymer surface area are critical and the shield can touch grounded chamber brackets. Choose the polyimide-wrapped '-J' version when the shield must remain floating (single-point ground) to avoid ground loops.
What does 'KAPM' mean compared with 'KAP' in the model designation?
'KAP' denotes a solid single-strand conductor (such as 311-KAP or 301-KAP-RIB), whereas 'KAPM' denotes a multistrand (19-wire) flexible conductor designed for repeated movement on in-vacuum manipulators and goniometer stages.
Can 301-KAPM-PAIR be used at liquid helium (4 K) temperatures?
Yes. Both aromatic polyimide film and silver-plated OFHC copper remain ductile and mechanically intact down to 4 K (-269 °C) without cracking during thermal cycling between cryogenic temperatures and +250 °C bakeout.

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301-KAPM-PAIR Polyimide UHV Screened Twisted-Pair Wire

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