[Domestic Material] Ergonomic Utility Knife Mahogany SDI 0439C
01 / AWARENESS
The utility knife stays the same — what changes is the part in your hand
A utility knife is one of the tools picked up most often on a desk. We kept SDI's original blade mechanism and auto-lock, and replaced only the part your palm touches with wood.
Specifically: the body is an SDI 0439C, with an Auto-Lock slider that SDI rates to withstand up to 8 kg of force; the grips on both sides are domestic mahogany, CNC-cut into an ergonomic curve. Overall it measures about 145 × 25 × 10 mm and weighs about 25 g, including the knife body and the wooden grips.
02 / MATERIAL
Domestic mahogany handle
Mahogany (Swietenia macrophylla) has a reddish-brown tone, fine and even grain, and a dense structure.
About the grain
• Each handle comes from a different piece of wood; differences come from the sawing direction (quarter-sawn / flat-sawn), growth ring width, and whether it was cut from heartwood or sapwood.
• Knots and grain variation are features of natural wood, not defects; product photos show actual pieces for reference.
03 / DESIGN
An ergonomic curve, right-hand version
The handle is cut to the curve of a right hand’s grip, so your palm rests against the wood. It is currently available in a right-hand version only.
04 / CRAFT
CNC-cut, sanded in two rounds
WKidea uses only CNC subtractive machining, cutting the curve of the handle from a solid block of wood, with no injection molding.
This product is priced at NT$500 and made with WKidea's standard craft: two rounds of sanding, with alcohol sprayed at the end of the first round so the wood fibers flattened by sanding stand back up, making the second round more even.
05 / HOW TO USE
How to use
01 Push the slider on the body to extend the blade, only as far as you need.
02 Release the slider and the Auto-Lock holds the blade in place.
03 When you are done, retract the blade completely.
04 When the blade gets dull, buy SDI 1361 or K361 replacement blades.
05 When not in use, store it in the black paper box.
Blades and replacements
• One SDI 1361 30° blade is installed in the body at shipping; no extra spare blade is included.
• For replacements, choose SDI 30° 9 mm blades: 1361 or K361.

Storage | Black paper box

Packaging | Windowed lid
Packaging photos show the Taiwan incense cedar version; all WKidea utility knife models use the same black paper box.
06 / CARE
Simple natural beeswax care
Retract the blade before care:
01 For everyday care, simply wipe the handle with a dry cloth.
02 Now and then, apply a thin coat of natural beeswax, then wipe off the excess with a dry cloth.
03 Avoid soaking it in water or leaving it in direct sunlight for long periods.
Beeswax for care: WKidea natural beeswax. Avoid long sun exposure and humid storage.
07 / FAQ
FAQ
Q: What body does this utility knife use?
An SDI 0439C professional precision knife: metal body and an Auto-Lock slider, which SDI rates to withstand up to 8 kg of force.
Q: Is a spare blade included?
No. One SDI 1361 30° blade is installed in the body at shipping; no extra spare blade is included.
Q: Which replacement blades should I buy?
SDI 1361 30° blades (9 mm) or SDI K361 black 30° blades (9 mm). According to SDI, K361 is SK2+Cr alloy tool steel with a Japanese-ground blackened finish.
Q: Can left-handed people use it?
It is currently available in a right-hand version only; the ergonomic handle is designed for a right-hand grip.
Q: What are the size and weight?
About 145 × 25 × 10 mm and about 25 g, including the knife body and the wooden grips.
Q: How soon does it ship?
It is in stock and ships 2–3 business days after you order.
Q: Will the wood grain look exactly like the photos?
No. Each handle comes from a different piece of wood, so grain and color vary; the photos are for reference only.
Q: How is it packaged?
In a black paper box.
08 / CUSTOMIZE
Bulk orders and customization
For corporate gifts, group orders or other needs, feel free to contact us.
1-on-1 consultation
• Line: @wkidea
• Email: service@wkidea.com
• We'll get back to you as soon as possible.
09 / WKidea
Practice makes perfect
WKidea approaches woodworking in the spirit of the old oil seller's tale: no shortcuts, only repeated practice. We use only CNC subtractive machining, and our founder Willy Kang has been an officially certified Autodesk Fusion instructor since 2017.