Fnirsi HS-02 Review: Keep soldering on!

The Fnirsi HS-01 was a bit out of the blue in 2023. After a slew of the best soldering irons and soldering stations passing across my desk, the HS-01 offered a cheap and consistent experience. Sure it was a little larger than a Pinecil or TS100, but that’s ok, because it was comfortable.

Now in 2024, Fnirsi has released the $29 HS-02 in two configurations, the HS-02A and what I have for review, the HS-02B. The difference? The HS-02A uses slightly longer (9cm) soldering tips and takes around five seconds to get to a working temperature. The HS-02B uses shorter 6.6cm tips and claims to heat up in 2 seconds (something that I cover later on).

Will the HS-02B make it to the best soldering irons page? Will I prefer it to my Pinecil v2 or dedicated Yihua soldering station? To know this, and more, I’ll need to dig out some electronics kits and get soldering!

Fnirsi HS-02B Specifications

Fnirsi HS-02 Look and Feel

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The HS-02 is a larger, chunkier soldering iron compared to the HS-01. When compared to the Pinecil or TS101, it is a hefty beast. But it is light in the hand, and feels comfortable to use, once you find your preferred grip point..

The “grip to tip” ratio is short, unlike with other smart soldering irons. We have a rubber guard / grip which is less than 2 inches from the tip of the iron. The rubber is knurled and grippy. The buttons and LCD screen are out of the way, and we won’t accidentally press anything when we are soldering.

The 0.96-inch LCD color screen is bright and clear. The interface is easy to understand, and not too cluttered. The addition of color is used sparingly, and really all you will notice is the red highlight identifying the channel (CH) in use.

Included in the kit is a generic stand, useful to keep your soldering iron from touching the desk. Also included is a rather nice “silicon” type USB Type-C power lead which keeps out of the way when soldering, unlike PVC cables which twist and snake around the desk. It also has some weight to it, meaning that it keeps still on the desk.

Powering the HS-02B

To power the HS-02, we can use either USB Type-C or DC power via a DC to USB Type-C adapter. The included 100W adapter provides more than enough power to get the soldering iron up to temperature. Should you not be near a USB Type-C power source, the USB Type-C to DC adapter is a viable option. You’ll need a 19V 2A or adapter in order to get a similar performance. At 19V 2A, the DC power supply will drop the voltage down to around 14V (confirmed with my Yihua 3005D III bench power supply). In order to keep the voltage at 19V, I needed to supply at least 2.5A.

Most of us will power the Fnirsi HS-02B via the 100W USB Type-C power supply. You can also use a 19V USB Type-C laptop charger, or in my case, I also tested with a Pine64 PinePower desktop power supply, which supplied 20V to the iron.

Soldering with the Finirsi HS-02

Let's get to the meat of it. The Fnirsi HS-02B heats up to 360 degrees Celsius in 3.6 seconds! This makes it the fastest soldering iron that we have tested! Just 3.6 seconds to get to a working temperature is amazing! I used the HS02B-K pointed chisel tip and it provided plenty of thermal mass to lay down the heat. It also gives us a sharp tip for precision.

Swapping tips is tool-less and we don’t have to unscrew a collet to loosen the tip. The tips have a 22 x 2.5mm section which is gripped by the iron. A 1.5mm thick section is used to make a connection to the power pins inside the soldering iron’s handle. This does mean that the HS-02 is incompatible with the HS-01’s tips, a damn shame as I already have a complete set for every soldering scenario.

I went through my standard soldering test. First I grabbed a 555 monostable switch kit, a classic kit to get to know the Fnirsi HS-02B. The HS-02B felt good in the hand, and my hand didn’t ache or slip during use.

The smaller components were soldered into place with no effort. The lead based solder just melted into place. For the larger joints, like the mounting pins of a 9-pin D-sub connector on a PIC microcontroller programmer board, it took just under a couple of seconds to melt the solder into place. I’m confident that this little iron could solder up thicker cable, but you would need to bump up the temperature to 450C to get the job done.

I mentioned earlier that I chose the HS02B-K soldering tip. I also have the HS02B-I (precision) and the HS02B-IS (precision hook). I tried out the HS02B-I and it was precise, but it also lacked thermal mass. Use this tip, or the HS02B-IS for surface mount soldering.

In my opinion, the HS-02A has a better selection of tips. Two knife tips (HS02A-K and KU), a hook tip (HS02A-JS), precision tip (HS02A-I), a general purpose conical tip (HS02A-B) and finally my personal favorite style of tip, the conical bevel edge (HS02A-C2). Why do I like that style of soldering iron tip? It provides the best of both worlds: lots of thermal mass, and just enough precision for most jobs.

Fnirsi HS-02 Software

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With smart soldering irons, they typically have a config file on a small “drive” inside the iron. We connect the iron to a computer and it becomes a mass storage device, with a config file that we can edit. This is not the case with the HS-02B. Instead we press both arrow keys to enter a configuration menu. From this menu we can set functions like the sleep timer and calibrate the iron.

The “Handle set” menu is where we can configure three preset temperatures, listed as CH1, CH2 and CH3. Using the arrow keys we select the temperature; pressing OK moves to the next CH. A long press of OK will return us to the Handle menu, and again to the main menu. After a short time, the soldering iron will revert back to the OK, flashing to indicate that it is ready to start soldering.

The user interface when soldering is pressing the ok button to switch between CH1, CH2 and CH3. The arrow keys can be used to tweak the temperature in 5 degree increments. This can be tweaked in the main menu, for finer or more coarse increments.

Firmware upgrades are handled via the System menu, under firmware. This sets the soldering iron up as a mass storage device. Just connect it to your computer, download the new firmware from the Fnirsi website, and drop the file on the drive. The next time you power up the HS-02B, it will have the latest firmware. I updated my review unit to v1.7 firmware, but I couldn’t see any difference to v1.6.

Bottom Line: Who is Fnirsi HS-02 For?

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The Fnirsi HS-02 is a good “upgrade” from the HS-01, and I can see it being used by hobbyists and professionals alike. Its fast heat up time makes it ideal for quick jobs, but it also has the power to tackle much larger projects. The price of the iron, $29 without a power supply makes it a bargain as most of us will have a compliant USB Type-C charger. Solid hardware, good software, and a low price make this a great iron for the workshop and the kit bag.