Select the exact curve and temperature grade
The R25 range and the −55 °C to +250 °C range do not define which combinations are available. Base each design on the R25, B value, R/T table and temperature limits of one part number.
| R25 | 0.1 kΩ–3.78 MΩ |
|---|---|
| Operating temperature | −55 °C to +250 °C |
| R25 tolerance | ±1% to ±10% |
| B-value tolerance | ±0.5% / ±1% |
| Thermal time constant, static air | ≤20 s |
| Rated power (25 °C) | ≤50 mW |
Axial glass-encapsulated NTC thermistors for temperature sensing and compensation. Operating temperature −55 °C to +250 °C, R25 0.1 kΩ–3.78 MΩ.

Part-number list on request. Download the datasheet or send us your specification.
Send your specificationDatasheets, technical documents and approval certificates for this series. English editions of documents marked “Chinese” are available on request.
Axial glass-encapsulated NTC thermistors for temperature measurement and compensation. Glass body 4.0 mm long and 2.0 mm in diameter, with 28 mm leads. R25 0.1 kΩ–3.78 MΩ, tolerance ±1% to ±10%. Operating temperature −55 °C to +250 °C; rated power ≤50 mW at 25 °C; thermal time constant ≤20 s in static air.
| Function | Axial NTC thermistor for temperature measurement or compensation; zero-power resistance decreases as the element temperature rises |
|---|---|
| Construction | NTC chip in axial glass encapsulation; family code 580 |
| Environmental compliance | RoHS and REACH compliant. Halogen status and material declarations on request. |
| Packing | Bulk |
| Rated zero-power resistance R25 | 0.1–3,780 kΩ (100 Ω to 3.78 MΩ) |
| R25 tolerance | ±1% · ±2% · ±3% · ±5% · ±10% |
| R25 code examples | 102 = 1 kΩ · 103 = 10 kΩ · 104 = 100 kΩ · 105 = 1 MΩ |
| Available values | R25, B-value and tolerance combinations: availability on request. |
| B-value tolerance | ±0.5% · ±1% |
| B-value definition | Defined from the zero-power resistances at T1 = 298.15 K and T2 = 323.15 K or 358.15 K |
| Temperature accuracy | R25 and B tolerances do not state a ±°C accuracy. Calculate the temperature error from the R/T table of the selected part. |
| Zero-power resistance | DC resistance at temperature t, measured at a power low enough that any further reduction changes the resistance by less than 0.1% |
| Operating temperature | −55 °C to +250 °C. Temperature grade and derating by part number on request. |
| Thermal time constant | ≤20 s in static air |
| Thermal time constant, definition | Time to reach 63.2% of the element temperature change, under zero-power conditions |
| Dissipation constant | ≥2.0 mW/°C in static air |
| Rated power | ≤50 mW at 25 °C |
| Glass body length | 4.0 mm (nom.); tolerances on request |
| Glass body diameter | 2.0 mm (nom.) |
| Lead length | 28 mm each side (nom.) |
| Lead diameter | 0.48 mm (nom.) |
| Glass seal | Glass encapsulated; no hermetic-seal rating is specified. |
| Terminal option | 0 = without terminal · P = with terminal; terminal type and drawing on request |
| Lead-length code | Last four characters of the part number; code table on request |
| Hand soldering and rework | Iron tip 300 °C max. · 3 s max. · joint at least 2 mm from the body |
| Storage | ≤35 °C · ≤70% RH · 12 months · keep the original package closed and reseal after opening |
| Corrosive atmospheres | Hydrogen chloride, hydrogen sulfide and sulfur compounds can degrade lead solderability. Avoid exposure. |
| Battery packs | Validate insulation, flame and fault behavior, lead abrasion and cell contact in the pack. |
| Further data on request | Nominal B value, reference temperatures and R/T table · power derating versus ambient temperature, allowed self-heating and sensing duty · max. working voltage and current, insulation resistance and dielectric withstand · lead alloy, plating and solderability class · leak, insulation and moisture data · wave or reflow soldering, welding or crimping, lead-forming distance, cleaning and potting conditions · dry-heat endurance, damp-heat, temperature-cycling, thermal-shock, vibration, lead-strength and solderability results |
Ranges by dielectric, package and lead style within this series.
| Variant | Body dimensions | R25 | Temperature range / thermal data / rated power | Lead / land pattern | Notes |
|---|---|---|---|---|---|
| MF58 / 580 axial glass | Glass body 4.0 × Ø2.0 mm (nom.) | 0.1–3,780 kΩ | −55 °C to +250 °C · τ ≤20 s · δ ≥2.0 mW/°C · ≤50 mW at 25 °C | Axial leads, 28 mm each side · Ø0.48 mm | Axial high-temperature sensing or compensation. |
Start with the temperature interval, duration and accuracy budget. Then select the part number by R25, nominal B value and R/T table, glass and lead construction, and temperature grade.
Set continuous and excursion temperature, humidity and condensation, corrosive media, response, self-heating allowance, life, mechanical load, calibration and the required ±°C accuracy.
Choose R25 within 0.1–3,780 kΩ. Nominal B value, reference temperatures, R/T table, temperature tolerance and drift for each part number and temperature grade on request.
Calculate worst-case current, voltage, power and self-heating across the curve and the ambient range. Correlate the ≤20 s static-air value with the actual PCB, airflow, probe, potting or contact assembly.
Specify glass seal, lead alloy and plating, dimensions and tolerances, terminal, lead length, packing, forming and bend limits, solder or weld heat sinking, cleaning and any insulation or potting system. STE data for each item on request.
Validate dry heat, humidity with bias, thermal cycling and shock, seal and insulation, vibration, lead strength, solderability, drift and the response of the finished assembly.
The R25 range and the −55 °C to +250 °C range do not define which combinations are available. Base each design on the R25, B value, R/T table and temperature limits of one part number.
The ≤50 mW rating applies at 25 °C. Obtain the power derating curve and limit the measurement current so that self-heating stays within the error budget at every resistance and temperature.
Glass encapsulation can support harsh environments, but no hermeticity, insulation or leak rating is specified. Validate humidity, condensation, corrosion and any exposure of live conductors in the finished assembly.
Form, clamp and pull leads away from the body with controlled tooling and heat sinking. Do not transfer PCB strain, crimp force or soldering heat into the glass seal.
The ≤20 s static-air value does not predict a potted probe, forced airflow, surface contact or battery assembly. Verify time constant, gradient and lead heat loss in the actual mounting.
Example ordering code. Not every combination is available.
MT · 580 · 103 · F · 3950 · F · 0 · 0000
| Code | Meaning |
|---|---|
| MT | Temperature-sensing NTC prefix |
| 580 | Family code: 580 = MF58 axial glass |
| 103 | R25: 103 = 10 kΩ; 102 = 1 kΩ, 104 = 100 kΩ, 105 = 1 MΩ |
| F | R25 tolerance: F = ±1%; G ±2%, H ±3%, J ±5%, K ±10% |
| 3950 | Nominal B value in K; available values and reference temperatures on request |
| F | B-value tolerance: F = ±1%; G = ±2%; ±0.5% on request |
| 0 | Terminal: 0 = without terminal; P = with terminal |
| 0000 | Lead length; the drawing shows 28 mm each side. Code table on request. |