Trivisa Firefly-CU 14C28N Blade Copper Handle Crossbar Lock Folding Knife

The Trivisa Firefly-CU combines a compact profile with practical materials for everyday carry and outdoor use. Its 2.99-inch 14C28N stainless steel blade features a black stonewash finish and a swedge style. Known for corrosion resistance and easy sharpening, 14C28N is a convenient, low-maintenance choice, though it may need more frequent touch-ups when cutting abrasive materials. A copper handle adds distinctive character, while the crossbar lock provides secure blade engagement. Ceramic ball bearings support smooth opening. The knife measures 6.75 inches overall and 3.76 inches closed, with a 2.8 mm blade thickness and a weight of 4.85 ounces. Designed by the TRIVISA team, it’s suited to everyday carry, hiking, camping, fishing, and other outdoor activities.

14C28N Blade Introduction

14C28N is a high-value budget-to-midrange stainless steel that excels in corrosion resistance and ease of sharpening, making it a low-maintenance workhorse for EDC and wet environments, but it falls short of premium steels in edge retention and requires more frequent touch-ups when cutting highly abrasive materials like cardboard.

SPECIFICATIONS

Designer:TRIVISA Team
Style:Swedge
Blade Material: 14C28N Blade
Blade Finished: Black Stonewash
Handle Material:Copper
Lock Style:Crossbar Lock
Hardness:60±2HRC
Bearing:Ceramic Ball Bearing

Size:
Overall length-6.75"(171.7mm)
Blade length-2.99"(76mm)
Closed length-3.76"(95.7mm)
Blade width-0.87''(22.1mm)
Blade thickness-0.11''(2.8mm)
Net Weight:4.85oz(137.4g)

Usage:Outdoor survival,EDC,hunting,fishing, hiking and camping

Trivisa Firefly-CU - Black Stonewash 14C28N Swedge Blade with a Solid Copper Handle

The Trivisa Firefly-CU pairs a 2.99 inch 14C28N swedge blade in black stonewash with a solid copper handle, a crossbar lock and ceramic bearings at 137.4 g (4.85 oz). More folding knives at EDCMALL.

Solid Copper in the Pocket

A solid copper handle is a commitment: 137.4 grams of living metal that darkens with every pocket trip, naturally antimicrobial, and dense enough to make the swing feel deliberate. Behind it sits a 2.99 inch 14C28N swedge blade in black stonewash - Sandvik's nitrogen stainless at 60+/-2 HRC, corrosion-proof and easy to touch up on any stone. The crossbar lock and ceramic bearings keep the action crisp. Compare 14C28N with D2, Nitro-V and 154CM in the table below.

Why the Firefly-CU Belongs in Your Pocket

• 2.99 inch 14C28N swedge blade at 60+/-2 HRC with a flat grind.
• Black Stonewash blade finish - a dark tumble treatment that reads black in low light and grey at the wear points.
• Solid Copper handle - solid copper scales that patina with handling and feel dense in the pocket.
• Crossbar lock: ambidextrous, dirt-tolerant and finger-safe on closing.
• Ceramic ball bearing pivot for a glassy swing.
• Thumb stud opening for one-handed deployment.
• Steel pocket clip, tip-up.
• 137.4 g (4.85 oz) on a 6.75 inch frame - a compact, honest EDC folder.

Best Uses for the Firefly-CU

• Daily pocket duty: mail, packaging and food runs on a blade that shrugs off rain.
• Copper lovers' rotation carry - the handle patinas into a one-of-one finish.
• Wet-weather hiking where 14C28N and Micarta both shrug off moisture.
• Office carry with a look that reads higher than its price.
• First folder for a new enthusiast - easy steel to maintain, safe lock to learn.

Frequently Asked Questions

What is the blade steel?
Sandvik 14C28N nitrogen stainless, hardened to 60+/-2 HRC. It is corrosion-proof, resists chipping and sharpens in minutes; expect more frequent touch-ups than a super steel under abrasive cutting.

What is the handle material?
Solid Copper - solid copper scales that patina with handling and feel dense in the pocket.

How does it open and lock?
The thumb stud swings the blade out one-handed on ceramic ball bearings; the crossbar lock wedges behind the tang from above and releases with a pull of the bar - fully ambidextrous.

What does the swedge do?
The bevel along the spine lightens the blade, sharpens the tip geometry and gives the Firefly its distinctive silhouette.

How big is it?
6.75" (171.6 mm) open, 3.76" (95.6 mm) closed, 2.99" (76 mm) blade at 0.11" (2.8 mm), and 137.4 g (4.85 oz).

Sandvik 14C28N vs. Common Pocket Knife Steels

Steel	Typical HRC	Edge Retention	Corrosion Resistance	Toughness	Sharpening Ease
14C28N (this knife)	59-61	Good	Excellent	Good	Very Easy
Nitro-V	59-61	Good	Very Good	Better	Easy
154CM	58-61	Good	Good	Very Good	Moderate
CPM-S35VN	58-60	Very Good	Very Good	Better	Moderate
D2 Tool Steel	58-61	Very Good	Fair	Good	Moderate
8Cr13MoV	57-59	Fair	Good	Good	Very Easy

Sandvik 14C28N is a nitrogen-refined martensitic stainless that lands at 58-61 HRC in production heat treats. On a value folder it is the smart pick: corrosion resistance that survives wet weather and pocket sweat, a fine stable edge that refuses to chip, and sharpening so easy a few passes on a pocket stone restore the apex. The trade is raw wear resistance - expect more frequent touch-ups than a high-vanadium super steel under abrasive cardboard work. HRC figures are typical mill ranges, not a guarantee for any single blade.

Glossary of Key Terms

Trivisa
A Chinese knife brand building value folders around practical steels, with a clean in-house design language.

Firefly
Trivisa's compact swedge-blade folder: 2.99 inch 14C28N blade, crossbar lock, ceramic bearings, 6.75 inches overall and 2.39 to 4.85 ounces depending on the handle material.

Sandvik 14C28N
A nitrogen-alloyed martensitic stainless at 58-61 HRC. Corrosion-proof, fine-grained, hard to chip and famously easy to sharpen.

Crossbar Lock
A spring-loaded bar spanning the handle that wedges behind the blade tang. Fully ambidextrous, keeps fingers out of the closing path, and among the strongest folder locks built.

Ceramic Ball Bearings
Hardened ceramic balls around the pivot. The action stays glassy for years, and ceramic will not rust or flat-spot.

Swedge
A bevel ground along the blade spine. It lightens the profile, sharpens the tip's geometry and adds a distinctive silhouette.

Micarta
Layers of linen or canvas compressed and cured in resin. It gets grippier when wet and wears into a personal patina over years of use.

Copper Handle
Solid copper scales with living-finish patina that darkens with handling; naturally antimicrobial and satisfyingly dense in the pocket.

Stonewash Finish
A tumbling process that beads the steel into a uniform matte grey, hiding carry scratches and killing glare far better than satin.

PVD Coating
Physical vapour deposition: a hard, thin metallic-ceramic layer bonded to the steel. Rose-gold and black finishes resist scratches; edge wear is cosmetic, not structural.

Black Stonewash Finish
A dark stonewashed treatment that reads black in low light and grey at the wear points. Hides scratches better than any satin.

60+/-2 HRC
The Rockwell C hardness band the blade is heat treated to: hard enough for long edge life, still honest to sharpen at home with patience.

Who Should Buy the Firefly-CU

• Buyers who want a genuine crossbar-lock folder under $90.
• Copper fans who want a living-finish handle with a working blade.
• Users with smaller hands who like a compact 6.75 inch frame.
• Wet-climate carriers who want maintenance-light stainless.
• Anyone building a colour-rotation EDC set on a budget.

Who Should Skip It

• Super-steel chasers - 14C28N trades edge life for easy care.
• Users who want heavy pry capability; the 2.7-2.8 mm blade is a slicer.
• People who dislike weight - the copper version carries at 4.85 ounces.
• Buyers who want flipper deployment; this opens on a thumb stud.

Care & Maintenance

• Wipe the blade dry after every use; 14C28N is stainless but the black stonewash finish lasts longer when wiped clean.
• One drop of light knife oil at the pivot every two months, then cycle the blade so oil reaches the ceramic bearing.
• Let the copper handle patina naturally, or revive it with a soft cloth and a drop of copper polish if you prefer bright metal.
• Keep solvents off the copper; they dull the surface tone unevenly.
• Sharpen on a 1000-grit water stone or ceramic rod at 15-18 degrees per side; 14C28N grinds fast.
• Blow lint out of the crossbar-lock channel before oiling; grit under the bar makes the action gritty.
• The copper adds real weight - check the pocket for the knife's seated depth and use the clip to keep it low.
• Check the pivot, body and clip screws every couple of months with the correct Torx driver.
• Never pry or twist the tip; the 2.8 mm blade is a slicer, not a lever.