A spring-loaded thermocouple is a sheathed temperature sensor designed for reliable surface temperature measurement on molds, machinery, bearings, heating equipment, and other industrial surfaces. A compression spring keeps the measuring tip firmly against the target surface, compensating for installation gaps and thermal expansion while helping maintain stable contact.

The armored probe provides good vibration resistance and repeatable measurement. Standard K, J, T, E, and N types are available with Φ3–6 mm probe diameters, M12×1.5 thread mounting, and SS304, SS316, or Inconel 600 sheath options. Probe length, spring travel, thread, cable, and connector can be customized for OEM and replacement applications.

Looking for a general mineral-insulated probe? See our Sheathed Thermocouple page for additional diameters, configurations, and mounting options.

Spring-Loaded Thermocouple Structure

The assembly consists of an armored temperature probe, compression spring, locking nut, threaded mounting seat, and extension lead. When the locking nut is tightened, the spring is compressed and continuously pushes the probe tip against the measured surface.

Key Features

• Spring-loaded contact: Compensates for thermal expansion, contraction, and installation gaps.
• Vibration resistance: Helps maintain stable probe contact on vibrating equipment and machinery.
• Armored probe: Provides mechanical protection and repeatable temperature measurement.
• Simple installation: Threaded mounting and spring compression allow installation and replacement without welding.
• Surface measurement: Designed for contact temperature measurement and not intended for immersion applications.

Thermocouple Type Selection

Choose the sensor type according to the required temperature range and application. For a broader comparison of K, J, T, E, N, S, R, and B types, see our thermocouple selection guide.

S/R/B types are available by special custom order. Actual operating temperature depends on sensor type, sheath material, probe diameter, installation conditions, and service requirements.

Stock Sizes

Standard thread is M12×1.5. M10×1.5 and other threads are available by custom order. Probe length can be cut within the stock range; lengths outside the listed range are custom. Standard spring travel is 8–15 mm, with custom spring lengths available.

General Options

Temperature and Spring Limits

The operating temperature depends on the selected sensor type and sheath material. The standard spring assembly has a maximum temperature limit of 400°C. For applications above 400°C, high-temperature spring components are required.

Installation

1. Screw the threaded mounting seat into the installation hole and tighten the locking nut.
2. The spring is compressed during installation and keeps the probe tip firmly against the measured surface.
3. Spring travel compensates for different installation depths and helps maintain contact during thermal expansion.
4. No welding is required, allowing convenient installation and replacement.

Important: This product is designed for surface contact temperature measurement. Do not insert the probe into a liquid, gas, or other process medium for immersion measurement.

Typical Applications

• Injection molding machines and molds
• Dies and plastic processing equipment
• Extruders
• Packaging machines
• Motor bearings
• Heating equipment surfaces
• Industrial machinery surface temperature measurement

For broader industrial applications, see our Thermocouple Applications page.

Custom OEM Solutions

EaseWise supports OEM and replacement production according to drawings, samples, photos, and technical specifications. Custom options include:

• Probe diameter and length
• Spring travel and spring length
• Thread and mounting dimensions
• Sheath material
• Junction type
• Connector and cable configuration
• Custom installation dimensions

For OEM or replacement requirements, send us the sensor type, probe diameter, probe length, spring travel, thread, sheath material, junction type, connector, lead length, and application details. Drawings, photos, or existing samples are also welcome.

Related Products

• Sheathed Thermocouple – general mineral-insulated probes with multiple diameters and configurations.
• Mini Plug Thermocouple – compact connection for quick installation and replacement.
• Threaded Compression Fitting Thermocouple – secure threaded or compression installation.
• Ultra-Thin Fine Diameter Sheathed Thermocouple – small-diameter construction for narrow spaces and fast response.
• Industrial Thermocouples – complete industrial temperature sensor range.

Request OEM Support

Need a custom spring-loaded thermocouple for an OEM or replacement project? Send us the sensor type, probe diameter, length, spring travel, thread, sheath material, connector, and application details.