B57164K (K164) is a leaded disc NTC thermistor family documented by TDK Electronics. The full ordering code identifies the resistance, tolerances, and construction variant; “B57164” alone is not enough to confirm a part’s electrical fit. This guide summarizes what OEM engineers should verify in the manufacturer’s current datasheet before designing in or sourcing a possible alternative.
Manufacturer clarification: B57164K is identified in TDK’s documentation as the K164 family. This article is an independent technical reference; it does not claim that Starlight manufactures or stocks TDK parts, and it does not assert that any Starlight sensor is a drop-in equivalent.
What the TDK K164 datasheet identifies
TDK describes K164 as a leaded NTC thermistor with 5 mm lead spacing, used for temperature measurement and compensation. The datasheet lists multiple resistance and B-value options, so values must be checked against the complete ordering code rather than inferred from the family name. The family document also lists its stated tolerance options and mechanical drawing; confirm the current revision and exact order code for any design or purchasing decision.
See TDK’s official K164 datasheet (PDF) for the authoritative dimensions, electrical tables, operating conditions, and cautions.
Checks before selecting or sourcing a variant
- Full ordering code: record the complete code and manufacturer; do not select by the shortened “B57164” family name.
- Resistance at 25 °C (R25): match the required nominal value and tolerance to the controller’s measurement circuit.
- B value and reference temperatures: verify the specific B-value pair and tolerance. Equal R25 values do not guarantee matching resistance curves.
- Temperature and power limits: check the operating conditions, dissipation, self-heating, and the application’s thermal environment in the datasheet.
- Mechanical fit: confirm disc dimensions, lead spacing, lead diameter, clearance, mounting method, and the actual heat-transfer path.
- Validation: compare representative samples over the required temperature points and test in the assembled system before approving a substitute.
How to evaluate an alternative
A candidate NTC should be compared using its own manufacturer datasheet and the complete application requirements. Check the resistance-temperature curve, tolerances, package and leads, thermal response in the intended mounting, electrical readout, and validation evidence. A similar appearance or nominal resistance is not sufficient to establish interchangeability. For general circuit considerations, see our NTC thermistor circuit guide and browse our NTC thermistor and sensor range.
OEM inquiry checklist
When requesting an NTC solution, share the required R25 and curve or B value, tolerance, temperature points, circuit input, mounting and lead constraints, environment, annual volume, and validation needs. Starlight can review those requirements and discuss suitable options; any proposed part must be verified against its own specification and tested for the application.
Contact Starlight Sensors with your NTC requirements for an OEM discussion.
