Frequently Asked Questions

You can find answers to the most commonly asked questions about Sandrin Knives below.

Our technologically advanced blades are engineered to stay sharp longer than any other knife. Guaranteed. Our blades are made from the hardest metal on Earth. In order to make a cutting blade with the world’s longest-lasting edge, we had to invent a new blade material: Polyhedral Tungsten Carbide (PTC), created with a patented process that gives our proprietary Tungsten Carbide its unique flexibility. We don’t just make the knife, we make the material that makes the knife. The primary reason knives grow dull relates to the hardness of the blade. The softer the steel, the quicker the edge is lost. Blade steels are measured on the C scale or, more formally, the Hardness on Rockwell scale C (abbreviated HRC). Blades considered to be of good quality typically measure between 54 to 62 HRC. Sandrin’s patented PTC blades have an HRC of 71, which delivers a dramatic increase in edge retention.  We call this advantage StaySharp Technology™.

It depends on what you cut but on average a Sandrin Knife will retain its razor-sharp edge on average 10 times longer than steel knives.

The maintenance of an edge is directly related to how a knife is used. Nothing lasts forever, but a Sandrin comes close. 

According to independent testing, our proprietary blades will stay sharp from 5 to 26 times longer than these popular knives.

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Polyhedral Tungsten Carbide (PTC) was invented by Sandrin founder, Alessandro Colombatto and his team. A second-generation tungsten carbide artisan, Alessandro and his parent company, Turmond, have been pushing the Tungsten Carbide industry boundaries for four decades. An established leader in tungsten carbide blades used for high-speed cutting applications, Alessandro has developed industrial cutting solutions for 21 different industries. 

PTC is composed of tungsten carbide and cobalt along with binder elements that have been used for decades in a variety of industrial applications, for example, crafting superior steel-cutting tools. However, traditional grades of tungsten carbide are brittle, so creating a durable knife blade from this material was previously thought to be impossible. Sandrin’s patented flexible PTC has solved this problem. In fact, our blades are so hard you can use the back edge of a Sandrin to sharpen traditional steel knives.

The physical properties of PTC fall in between the properties of ceramic and steel.  Ceramic is harder than polyhedral tungsten carbide but very brittle. Steel is less hard than TC but has good bendable properties.  PTC is about 30% to 50% harder than steel with similar cutting properties as ceramic. A Sandrin blade has a weight of about twice that of a steel blade and a density similar to gold.

Sandrin knives are designed for cutting and slicing.  Sandrin knives are NOT prying or chopping instruments.

A Sandrin Knife will hold its edge many times longer than steel.
Re-sharpening a PTC blade is best accomplished with high-speed diamond grinding wheels but a Sandrin PTC blade can be sharpened using diamond sharpeners commonly available on the market .We suggest a D20 diamond grit for a first manual maintenance . If more support is needed we would be glad to get contacted from our customers in order to provide proper solutions.
However, if you want to take on Sharpening your Sandrin Knife at home, you can follow the steps in this video: Is it possible to home sharpen Tungsten Carbide?. You bet. Much harder than steel, many EDC users may never need to resharpen a Sandrin Polyhedral Tungsten Carbide blade but this condensed video courtesy of sharpening wizard Ben Spaloss @makethepre shows his process on how to restore a razor sharp edge. Follow Ben on YouTube Stones&Strops or @marktpre on Instagram to see more on his channel. Thanks for sharing Ben! Here is what a list of equipment Ben uses: Zhuk Fixed Angle Knife Sharpener (other sharpening systems can also be used) Zhuk Knife Sharpener Digital Angle Gauge Digital Angle Gauge 2×6 Jende Diamond Lapping Pads, 30 microns, 9 microns and 3 micron×6-jende-diamond-films-3-pieces.html 2×6 Acrylic Blank×6-acrylic-blank.html Experienced folks at sharpening like Ben are able to sharpen Tungsten Carbide without a fixed angle sharpener but that will be difficult for average folks. Note: This sharpening method does not necessarily apply for steel knife sharpening.

The Sandrin knife has a hardness as measured in Rockwell at HRC71.  Most steel knives have a Rockwell hardness in the 50’s, while the hardest knives are in the 62 to 64 HRC range.  Mythical levels of knife level hardness have been reportedly achieved by one company at 67 HRC. Sandrin Knives are truly in their own class in terms of a durable cutting edge.

Traditional grades of Tungsten Carbide are brittle and can shatter. Sandrin PTC is a new patented grade of TC that has been engineered to reduce brittleness and add flexibility.  Watch our video of a Sandrin knife being dropped from a height of two stories.   Please note we do not advise dropping any knife from a height of two-stories.  That is abuse.

The famed Fibonacci sequence inspires the five precisely placed holes in the blade. Discovered in the thirteenth century by Leonardo of Pisa (better known as Fibonacci), it is a series of numbers which forms a seemingly divine sequence that appears recurrently in nature and other beautiful things. Fibonacci’s numerical pattern has fascinated mathematicians, scientists, and artists for centuries.

Sandrin Knives warrants to you, the original purchaser, that a knife was manufactured free of defects in material or workmanship; and for a period of 30 days from receipt of purchase, the manufacturer agrees to correct your tungsten carbide knife by repair or replacement (with the same or comparable quality model). Sandrin Knives reserves the right to inspect, examine, and/or test the knife to assess any claim made.  This warranty is void if the knife has been abused, misused, damaged by accident. This warranty does not apply to normal wear and is void if any unauthorized repair and/or alteration has been performed on the knife

All folding knives can loosen up after repeated opening and closing.  Our first generation TCK and TCK 416 (no longer in production) were designed with a locking system that is easy to adjust using a T6 and T8 Torx wrench.  Follow the instructions in the Video below.

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