Built to Adapt, Engineered to Perform.
This is FK Iron's first machine to introduce patent-pending stroke adjustment technology, allowing changing strokes while the machine is running from 2.0mm to 5.0mm in 0.5mm increments. With their artist first design, the Adjust adapts to any style or technique with ease. Take on your boldest linework to your finest detailing with this one machine.
With their updated battery it shows both voltage and hertz and with the drop in battery design it is easy to keep the batteries fresh and have your machine last longer. Long sessions won't be a problem as each battery will last around 6 hours, and each Fk Irons One Adjust comes with two inner batteries for keeping in going.
The FK One Adjust’s precision-engineered motor system pairs a fixed-stroke cam with a refined paddle and slider assembly that adjusts stroke length by moving closer to or farther from the paddle’s center. This constant-load design minimizes friction and wear, delivering long-lasting, high-caliber performance.
Product Manual: Download PDF
Features
- Adjust stroke while powered on between 2.0mm to 5.0mm, with 0.5mm increments for the smallest of adjustments
- Drop in battery design guarantees long life with a simple swap of internal battery
- 2 year warranty
- Upgraded digital screen for ease of use
- Able to be configured for right or left hand preference
- Comes with two internal batteries for ease of changing
- Adjustable needle depth
Technical Specs
- Output Voltage: 5V-12V adjustable in 0.2V increments
- Battery life 18500A Battery: 5.5 hours (depending on conditions and settings)
- Battery life 18650A Battery: 6.5 hours (depending on conditions and settings)
- Assembled length with short battery cap: 142mm x 38mm
- Assembled length with long battery cap: 152mm x 38mm
- Assembled weight with short battery:249g
- Assembled weight with long battery:267g
- Adjustable needle depth
- Sadly not autoclavable
- The FK One Adjust’s precision-engineered motor system pairs a fixed-stroke cam with a refined paddle and slider assembly that adjusts stroke length by moving closer to or farther from the paddle’s center. This constant-load design minimizes friction and wear, delivering long-lasting, high-caliber performance.
Shipping & Returns
All deliveries are sent by Australia Post with the choice of Express or Parcel post at checkout. Delivery charges are calculated using actual Australia Post rates. Please check here for more info.
Warranty
The warranty period for FK Irons is 24 months from date of purchase.
Please reach out to our customer service team at sales@bstattoo.com.au or by phone on 03 5272 1161 9am-4pm where we will diagnose and advise for next steps.
Not sure if this is the best tattoo machine for you? Compare Tattoo Machines
WHY CHOOSE FK ONE ADJUST?
OVERVIEW
- VOLTAGE READOUT SCREEN
- ERGONOMIC GRIP
- ADJUSTABLE STROKE BRUSHED MOTOR
- RATCHET, ADJUSTABLE NEEDLE DEPTH SYSTEM
ARTIST-FIRST DESIGN
Designed with artist input from the get-go, this machine is made to take on the challenges you face day to day.
RELIABLE & STABLE
An upgraded digital display gives you total clarity over your operating parameters.
INNOVATION THAT DELIVERS
Unlike other adjustable stroke machines, FK One Adjust lets you change your stroke on the fly without ever having to power down.
VERSATILITY WITH NO LIMITATIONS
FK One Adjust adapts to any style or technique, so you don’t have to choose between machines.
BUILT TO OUTLAST
Durable and supported by our upgraded global service program, the FK One Adjust is with you for the long-haul.
ARTIST-FIRST DESIGN
Designed with artist input from the get-go, this machine is made to take on the challenges you face day to day.
RELIABLE & STABLE
An upgraded digital display gives you total clarity over your operating parameters.
INNOVATION THAT DELIVERS
Unlike other adjustable stroke machines, FK One Adjust lets you change your stroke on the fly without ever having to power down.
VERSATILITY WITH NO LIMITATIONS
FK One Adjust adapts to any style or technique, so you don’t have to choose between machines.
BUILT TO OUTLAST
Durable and supported by our upgraded global service program, the FK One Adjust is with you for the long-haul.
BUILT TO ADAPT, ENGINEERED TO PERFORM
THE FK STANDARD, REDEFINED
CREATED FOR ARTISTS WHO:
• Need one machine for lining, shading, and packing
• Adjust on the fly without losing focus
• Travel light to cons or guest spots
• Expect tough, top-tier performance
Ergonomic Grip
For comfort and control during long sessions
Twist & Lock Battery Cap
- Long Cap for NCR 18650A battery
- Short Cap for NCR 18500A battery
Adjustable Stroke Technology
- Patent-pending stroke adjustment system lets you adjust stroke length without powering down.
- Stroke adjustment from 2.0mm up to 5.0 mm in 0.5mm increments.
Control Buttons
- Memory Save (Voltage/Hertz)
- Change Screen Orientation (Left/Right)
- Toggle Display (Voltage/Hertz)
Digital Screen (Dual Voltage + Hertz Display)
Can be configured for both right- and left-handed artists,ensuring optimal visibility from any angle.
Let's hear it from the pros:
What tattoo artists are saying?
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FAQ
How do I turn the machine on and off?
Tap the center red button to wake it up, then tap it again to start the motor. Tap once more to stop it.
If you don’t touch anything for 15 seconds (with the motor off), it goes to sleep automatically.
What voltage range should I run this machine at?
It runs safely between 5V and 12V. Use the 0.2V step buttons to dial in your preferred hit.
Just don’t push past 12V — the machine works best within spec.
Can I save a voltage setting I like?
Yep. Hold the Power button for 3 seconds until the screen blinks. Your preferred setting is now locked in.
How do I flip the screen for left-handed use?
Hold Down + Power at the same time to flip the display.
Do it again if you want it flipped back.
Can I change the stroke while the machine is running?
Absolutely. Twist the battery housing while holding the machine ring:
- Clockwise = longer stroke
- Counterclockwise = shorter stroke
Each click = 0.5mm, adjustable from 2.0mm to 5.0mm.
How do I adjust needle depth without the grip slipping?
Twist the grip while holding the machine ring.
Each click = 0.2mm adjustment.
The ratchet lock keeps your grip from shifting mid-session.
What batteries and chargers should I use?
Use only Sony, LG, Samsung, or Panasonic batteries.
Charge them using the included eFest Slim K2 USB-C charger. It auto-shuts off when full.
My machine won’t turn on. What should I check?
Most of the time, the battery cap isn’t fully tightened.
Make sure the arrow and lock icons line up, the cap is threaded completely, and that the battery is properly seated.
Why does the voltage feel different with some cartridges?
Some needle brands create extra resistance. If the motor feels off, loosen the grip slightly — that usually fixes it.
Are there tutorials on how to use or set up the machine?
Definitely. FK Irons has tons of videos and tips here: YouTube - FK Irons
What’s the warranty on the FK ONE Adjust, and how do I make sure it stays valid?
Your machine comes with a 2-year warranty that covers any manufacturing issues. If something goes wrong that’s not your fault, FK Irons will repair or replace it for free.
To keep your warranty valid, just avoid the big no-no’s:
- Don’t open it up or mess with the internals
- Don’t drop it or expose it to moisture
- Don’t use cartridges without a membrane
- Don’t run it past its max voltage
- Don’t autoclave it
And don’t forget to register your machine by scanning the QR code on the box — that activates your warranty and gets you product updates:
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