10-Pack KW12-3 Micro Roller Lever Limit Switch PCB Microswitch

10-Pack KW12-3 Micro Roller Lever Arm Limit Switch — PCB Microswitch

Get reliable, fast-action switching performance with this 10-piece set of KW12-3 Micro Roller Lever Limit Switches. Designed for PCB (printed circuit board) mounting, these compact microswitches deliver precise, snap-action operation across a wide range of DIY electronics, automation, and appliance applications. Each switch features a roller lever arm for smooth, consistent actuation — ideal for makers, engineers, and hobbyists alike.

Key Features

• Model: KW12-3 Micro Roller Lever Arm Limit Switch
• Rated Voltage: AC 125V–250V
• Current Rating: 5A
• Operating Temperature: -40°C to 70°C — suitable for demanding environments
• Compact Size: 20 × 10 × 6 mm (L × W × H) — easy to integrate into tight spaces
• PCB Terminals: Direct circuit board mounting for clean, secure installation
• Roller Lever Arm: Provides smooth, consistent mechanical actuation
• Material: Durable plastic housing
• Low Operating Force: Small stroke action with fast-break contact for high responsiveness
• Pack Quantity: 10 switches included

How It Works

These microswitches use a snap-action reed mechanism. An external mechanical force — applied via the roller lever — acts on the internal reed. When the force reaches a critical point, the reed snaps instantaneously, causing the moving contact to connect or disconnect from the fixed contact. When the force is released, the reed returns to its original position through reverse snap-action. This delivers fast, reliable, and repeatable open/close switching with minimal travel distance and operating force.

Wide Range of Applications

These versatile microswitches are compatible with a broad array of applications, including:

• Computer mice and peripherals
• Automotive electronics and car accessories
• Communications equipment
• Test and measurement instruments
• Gas water heaters and gas burners
• Small home appliances, microwave ovens, and electric rice cookers
• Floating ball valve equipment
• Building automation systems
• Electric power tools
• 3D printers and CNC machines

Package Includes

• 10 × KW12-3 Micro Roller Lever Limit Switches

Made in China.

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Frequently Asked Questions

Q: What voltage and current are the KW12-3 micro roller lever limit switches rated for?

A: Each KW12-3 microswitch is rated for AC 125V–250V and a current of up to 5A, making them suitable for a wide variety of low-to-medium voltage electronics and appliance applications.

Q: Are these microswitches compatible with PCB (printed circuit board) mounting?

A: Yes, the KW12-3 switches feature PCB terminal connections, allowing them to be mounted directly onto a circuit board for a clean and secure installation. Their compact 20 × 10 × 6 mm size makes them easy to integrate into most PCB layouts.

Q: What is the operating temperature range for these limit switches?

A: These microswitches operate reliably in temperatures ranging from -40°C to 70°C, making them well-suited for both indoor electronics and more demanding environmental conditions.

Q: Can these switches be used in 3D printers or CNC machines as endstops?

A: Absolutely. The KW12-3 roller lever limit switch is a popular choice for 3D printer endstops and CNC homing switches due to its precise snap-action, compact size, and consistent actuation force.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.