FNIRSI SWM-20 Handheld Spot Welder

The FNIRSI SWM-20 handheld spot welder combines high power, precision, and ease of use in a compact, portable design. With a maximum welding current of 1,200 A, dual-pulse technology, and over 10,000 adjustment levels, you can tailor the settings to various materials and applications. High-capacity batteries ensure long operating time, and the color TFT display makes it easy to monitor all key settings in real time. The device also functions as a 5,000 mAh power bank, making it ideal not only for workshop use but also for field work. It’s a versatile solution for professionals, service technicians, and DIY electronics enthusiasts.

Black FNIRSI spot welder with the display turned on, buttons, and a blue knob.

Power That Ensures Durable and Clean Welds

The FNIRSI SWM-20 generates a peak current of up to 1,200 A, enabling strong and repeatable welds on many types of materials. The dual-pulse technology ensures cleaner and more stable welds—the first pulse removes the oxide layer from the material’s surface, while the second pulse ensures the weld is performed correctly, improving its cleanliness and stability. The device supports materials with thicknesses ranging from 0.1 to 0.5 mm, including nickel-plated steel up to 0.4 mm, steel up to 0.5 mm, pure nickel up to 0.25 mm, iron up to 0.3 mm, and copper and nickel-plated copper up to 0.1 mm. With over 10,000 power adjustment levels and the ability to individually set parameters such as preheating, pulses, intervals between them, or the number of welds performed in continuous mode, allow you to precisely tailor the device’s operation to the specific material and task at hand.

A person wearing gloves holds the two tips of the spot welder, pressed against metal components on a tabletop.

Full Control and Convenient Operation

Operating the device is made easier by a clear, 2.4-inch color TFT display that shows voltage, temperature, and all key welding parameters in real time. An intuitive rotary knob allows for quick and highly precise adjustment of settings, ensuring that parameter changes can be made efficiently even during intensive operation. The sealer also supports software updates via the USB-C port, allowing you to take advantage of future improvements and new features.

Spot welder with connected cables, whose pins touch the tape on the blue battery cells.

High-Capacity Battery and Practical Design

The device is equipped with two high-quality battery cells with a total capacity of 5,000 mAh, ensuring stable operation and sufficient power reserves even during demanding tasks. A single charge allows for up to 1,500 welds, reducing the need for frequent recharging. Fast charging via the USB-C port (5 V / 2.1 A) shortens the time needed to prepare the device for further use. The FNIRSI SWM-20 can also function as a power bank, offering a 5 V / 2.1 A USB output to power or charge other devices. The detachable welding tips are equipped with 99.9% pure copper tips, which ensure excellent conductivity, effectively dissipate heat, and are highly durable.

A spot welder standing on a wooden table outdoors, charging a cell phone connected via a cable.

Safety During Every Operation

The FNIRSI SWM-20 is equipped with an intelligent eight-protection system that safeguards the device against, among other things, overheating, undervoltage, overcharging, over-discharge, short circuits, voltage fluctuations, operation at low temperatures, and the effects of impacts. An additional convenience is the automatic shut-off function with an adjustable timer ranging from 0 to 99 minutes, which helps save energy and enhances safety during use. This soldering iron is ideal for building battery packs, repairing electric bicycles, replacing smartphone batteries, and many other electronics and DIY projects.

The handle of a spot welder cable with a copper threaded tip unscrewed.

Included in the set

spot welder
welding tips
replacement tips
USB-C cable
nickel strip
user manual

Manufacturer	FNIRSI
Model	SWM-20
Battery capacity	5000 mAh
Output	5 V / 2.1 A
Welding thickness	0.1–0.5 mm
Preset combination levels	4 levels
Charging	5 V / 2.1 A
Welding Materials	Nickel, iron, stainless steel
Maximum Welding Current	1200 A

Welding tools

FNIRSI SWM-20 Manual Spot Welder