The KF390 / DG390 5.0mm Pitch 4-Pin Spring Terminal Block is a screwless, push-in cage clamp terminal block designed for fast, tool-free wire-to-board electrical connections. Constructed with a flame-retardant polyamide housing and high-tension stainless steel spring contacts, this 4-way terminal block provides vibration-resistant wire retention, low contact resistance, and rapid wiring assembly. It is widely used in industrial automation, stepper motor drivers, RGB/RGBW LED lighting controls, multi-sensor breakout boards, and microcontroller development projects.

Specifications

• Model / Series: KF390 / DG390 Series (Screwless Spring Terminal Block)
• Number of Pins / Ways: 4-Pin (4-Way)
• Pin Pitch / Spacing: 5.0mm (0.197 inches) / 5.08mm compatible
• Termination Method: Push-In Spring Clamp (Screwless / Tool-Free lever actuation)
• Rated Voltage: 250V to 300V AC/DC (IEC / UL standard)
• Rated Current: 10A (IEC) / 8A to 10A (UL)
• Dielectric Withstanding Voltage: 2000V AC for 1 minute
• Contact Resistance: ≤ 20mΩ
• Insulation Resistance: ≥ 5000MΩ (at 500V DC)
• Applicable Wire Gauge: 22 AWG to 14 AWG (0.5mm² to 2.5mm² solid or stranded wire)
• Wire Strip Length: 8mm to 10mm
• Housing Material: Polyamide (PA66, UL94 V-0 flame retardant)
• Contact / Pin Material: Tin-Plated Brass / Phosphor Bronze Solder Pins
• Spring Clamp Material: High-Tension Stainless Steel
• Operating Temperature Range: -40°C to +105°C
• Mounting Type: PCB Through-Hole Solder Mount

Features

• Screwless Push-In Clamping: Enables fast, one-handed wire insertion by simply depressing the top spring actuator lever with a small flat screwdriver or finger.
• Vibration-Proof Retention: Constant spring pressure automatically compensates for wire temperature changes and eliminates screw loosening caused by mechanical vibrations.
• Standard 4-Pin Form Factor: Ideal for 4-wire interfaces such as bipolar stepper motors (A+, A-, B+, B-), I2C communication (VCC, GND, SDA, SCL), SPI interfaces, and RGB lighting.
• Compact 5.0mm Pitch: Provides a space-efficient PCB footprint while maintaining sufficient high-voltage clearance and creepage distance.
• Flame-Retardant Housing: Molded from high-grade UL94 V-0 PA66 thermoplastic for reliable thermal stability and safety under continuous current loads.
• Modular Side Interlocking: Features side dovetail tabs allowing multiple blocks to be linked together to form custom-length terminal strips.

Common Applications

• Stepper Motor Controllers: 4-wire coil connections (A+, A-, B+, B-) for CNC machines, 3D printers, and robotic drive modules.
• Communication & Sensor Buses: Quick connections for 4-pin digital protocols including I2C, RS485, and UART interfaces (VCC, GND, TX, RX).
• LED Lighting Systems: DC power and signal routing for 12V/24V RGB and RGBW LED strips and controllers.
• Microcontroller Prototyping: Multi-channel I/O and power distribution for Arduino, ESP32, and Raspberry Pi breakout boards.
• Industrial Control Panels: Field wiring for sensor arrays, limit switches, and discrete DC automation signals.

Usage Tips

• Wire Preparation: Strip approximately 9mm of insulation from the wire end. For stranded copper wire, twisting the strands or crimping a bootlace ferrule ensures smooth, snag-free insertion.
• Wire Insertion: Press the top actuator lever down firmly using a 2.0mm–2.5mm flathead screwdriver, insert the stripped conductor fully into the clamp opening, and release the lever to lock.
• Soldering Precaution: Solder the through-hole pins at 350°C for no more than 3 seconds per pin to avoid thermal softening of the plastic casing or misalignment of the pins.
• Current Handling: Ensure PCB copper traces connecting to high-current pins (e.g., motor drive outputs) have adequate trace width or solder reinforcement to carry up to the 10A rated capacity safely.