Renchi：Modern Wrench Re-Engineered.

Let’s cut to the chase. Meet Renchi, a modern wrench re-imagined, with the 3 features that we’re the most proud of.

Ditch the worm gear! Why waste time spinning a dial? Just slide the jaw into position and start fastening. It’s not just a time-saver; it’s so intuitive it feels like second nature from the very first grip. 

One wrench fits all is what we’re aiming for. With a massive 80mm jaw capacity, Renchi handles everything from delicate assembly to home repairs 

Designed for high-stakes mechanics, the self-locking mechanism fits nuts like a glove. By eliminating the jiggles found in traditional wrenches, Renchi prevents the dreaded rounding of bolt heads. It’s the snug fit for your project and serve far beyond what a wrench could do.

It’s a toolbox staple, sure. But we’ve all had those moments where “good enough” just doesn’t cut it.

When changing size from a M12 to a M3 nut, much time goes wasted getting the right width.

And oftentimes, a regular 6 inches monkey wrench only goes up to 25mm, widely limiting the range when working in different fields.

When we finally get to the right size that fits, the wobbly worm drive often rounds off the outer surface of the nut, causing irreversible damage. The idea of making traditional monkey wrenches more reliable and comprehensive for professional work has taken over our mind. So the journey began.

We certainly weren’t the first one who attempted to find an improved version of the wrench. We dove into the archives of old patents and designs on self-locking mechanisms. A particular patent from Terry Coleman in 1897 that caught our attention.

Its beauty lay in its simplicity, moving the jaw along a linear axis without rotating gears. Fewer parts, fewer gaps, more reliability. However, the original design lacked the clamping force necessary for high-torque applications, and it required two hands to adjust—hardly practical for a modern pro.

By integrating 12 heavy-duty locking plates into a compact space, we’ve maximized the friction surface area. The result? A clamping force that holds firm under extreme loads. Whether it’s a stubborn rusted bolt or a high-torque industrial fitting, Renchi stays put.

We took a page out of the caliper’s playbook. Just like your favorite measuring tool, Renchi is designed for effortless, one-handed adjustment. It’s so familiar that there’s zero learning curve—if you can slide a thumb, you can tackle any bolt.

Need extra “teeth” for those awkward angles? Renchi features a serrated jaw tip for maximum bite force. Whether you’re dealing with stubborn, rusted nuts or delicate precision work, this added texture provides the mechanical traction you need to prevent slipping.

Renchi consists of only 5 part: 1. Locking Plate, 2. Spring, 3. Adjustable Jaw, 4. Switch, and 5. Handle. 
By stripping away the complexity, we’ve eliminated the “slop” found in traditional wrenches. Fewer parts, fewer gaps, fewer headaches.

Because there are only 5 components, cleaning or replacing parts for Renchi is a breeze. It’s so straightforward that taking it apart and putting it back together feels less like a chore and more like a satisfying puzzle game.

At only 10mm thick, Renchi thrives where others fail. Its ultra-low profile allows you to reach into narrow gaps and awkward angles that would leave a bulky monkey wrench stuck at the door.

We’ve hit the sweet spot between portable convenience and serious leverage. Renchi offers a balanced in-hand feel that’s light enough for your tool belt but heavy-duty enough to deliver the torque you demand.

We believe in Form Follows Function. Renchi doesn’t need flashy gimmicks or unnecessary plastic covers. Every detail has a purpose, letting the raw mechanical beauty and core performance speak for itself.

With a surface hardness that rivals the toughest materials on Earth, the specialized heat treatment gives Renchi a “ceramic-like” armor. It shields the tool from scratches and nicks, ensuring that even after a day of battling sharp edges and rough surfaces, your Renchi still looks and performs like new.

Like all world-class hand tools, Renchi is drop-forged under extreme heat and pressure. This process creates a superior grain structure, providing excellent shock absorption and high fatigue resistance. It’s so rugged that in a pinch, it doubles as a handy hammer without breaking a sweat.

We’ve combined the best of both worlds. By pairing 4 types of high-performance steel, we achieve the impossible: extreme tensile strength paired with incredible surface durability. It’s a powerhouse built from the inside out.

• Chrome vanadium (Cr-V) steel
• Japanese SK-5 steel
• Chromium-Molybdenum Steel (Cr-Mo)
• SUS304

Building on a reinforced classic architecture, we’ve integrated specialized details that transform Renchi into a versatile multi-tool. It’s engineered to adapt to any challenge, from the workshop to the wilderness.

With laser-etched scales in both systems, Renchi doubles as a reliable caliper. Simply slide the jaws to fit your object for an instant, accurate outside measurement.

Need a quick measurement on the nuts? Renchi also provides a scale for quick measuring for the size of your nuts in both inches and metrics.

The synergy of a wide opening and massive leverage turns Renchi into a powerhouse clamping plier. Whether it’s a rounded-off bolt or a stubborn metal cap, Renchi provides the crushing grip needed to break it loose.

The subtly angled jaw on the opposite side is perfectly profiled to pry off caps, making Renchi your best friend for a cold drink after a long day’s work.

No need to reach for a knife. The slim, dull edge of the jaw is perfect to glide through packaging tape effortlessly while keeping your fingers safe.

Need more torque for a stubborn screw? Clamp a standard hex bit into the jaws to create a high-leverage bit driver. The handle’s length provides the mechanical advantage required to conquer rusted or over-tightened fasteners.

In a messy construction site, an extra hanger to keep your gear bag from the dusty floor always comes in handy. Renchi’s jaw structure allows it to function as a sturdy desk hook, providing a reliable place to hang your bag or headlamps.

When locked shut, the heavy-duty jaw tips provide a solid striking surface for driving nails.

Need to undo a mistake? Flip it over—the handle’s ergonomic length provides the perfect leverage for extracting nails with minimal effort.

Renchi provides the rock-solid hold needed for delicate craftsmanship. But it doesn’t stop at clamping—by reassembling the jaws in reverse, Renchi transforms into a mechanical spreader, allowing you to apply controlled outward pressure to hold irregular shaped objects.

Renchi is not only going to be your tool box staple, but a reliable tool that does it all in versatile scenarios.

Weight: 210g
Measurements: 52.6 x 166 x 10mm
Materials: Cr-Mo | Cr-V | SK5 | SUS304 | SWP-A

We are a group of thinkers and problem solvers in pursuit of smart solutions, we are firm believers in the philosophy that form follows function.

The old design consists of 3 main parts: Inner bar, locking plates, and a handle. The frictional forces, f1​ and f2​, attempt to rotate the plates counter-clockwise. However, this rotation is obstructed by the jaw shank. The more force applied, the greater the friction becomes—creating a self-locking effect. With precisely engineered dimensions, these plates effectively prevent the jaws from sliding open under load.

However, after putting the model under calculation, for tightening a standard M12 nut, it requires the locking plate to withstand a force of 789 kg. It is nearly impossible for any material to withstand such high force without undergoing permanent deformation.

By translating our designs into functional prototypes, we were able to refine the details through real-world testing, resulting in Renchi as the answer for a better adjustable wrench.