BUT FIRST AN IMPORTANT RESOURCE ALERT
An invaluable resource for anyone interested in knives is Dr. Larrin Thomas’ website and his excellent book “Knife Engineering: Steel, Heat Treating, and Geometry.” I started investigating knife metallurgy and having blade samples examined by metallurgists in the 1980s and it was quite rare at the time. Over the years I managed to develop a pretty good understanding of practical knife blade metallurgy and used metallurgical examinations to solve many of the problems I encountered in both industrial knife making and in my shop. I also came to realize there was a big difference in “steel metallurgy” and “knife steel metallurgy” and spent many years trying to bridge the gap between the two. Blades face performance challenges that most tools do not so they require a targeted metallurgical study which Dr. Thomas provides.
The Test
The Rockwell C scale test is made by slowly elevating a specimen against a diamond ground to a 120 degree cone with a 0.2 mm spherical apex until a minor load has been applied. This minor load is approximately 22 lbs. and serves to position the indenter with respect to the face of the sample. A major load of 330 lbs is then applied and released and the depth of the indentation between the minor and major load is measured. This measurement is then translated to the C scale number. Obviously the softer the material the deeper the indentation and the harder the material the shallower the indentation.
What the Test Will Do
Once a heat treatment/microstructure has been determined a Rockwell hardness is taken and used as a indication of whether the heat treatment has been correct and consistent. It is a fast and easy test that can be done on the factory floor with a relatively inexpensive piece of equipment and is typically done to samples at every stage of the heat treatment and documented. Any change in the hardness readings once the procedure has been established will indicate a problem in the heat treating equipment or steel and will result in an investigation of the cause. So Rockwell hardness testing works very well as a quality monitor for heat treating.
What the Test Will Not Do
Steels are heat treated to a specific microstructure and the Rockwell C scale is only a gross indicator of the microstructure of the steel and cannot be considered a direct indicator of whether a knife will be tough or take and hold a keen edge. Blades of the same material and hardness can have very different performance characteristics depending on their condition prior to heat treating and the specific processes of hardening and tempering. Different steels require different austenitizing temperatures and soak times, different quench speeds and different tempering temperatures and times to produce the final optimized microstructure.
So it is not a case of higher Rockwell numbers being better than lower numbers because each steel has a fairly tight range of “hardnesses” (microstructures) that optimize the heat treated condition of the steel.
Some important performance factors that the Rockwell hardness test will not reveal is carbide amount, size and distribution, amount of retained austenite, it does not directly relate to material toughness or wear resistance but will usually correlate to yield strength. This can be important when predicting edge stability but is less of an indicator than blade/edge geometry, material and heat treatment.
Modern Heat Treating
In modern industrial heat treating knives are processed in either vacuum furnaces for stainless and high alloy steels or salt pots for carbon and low alloy steels. Both have precise digital controllers and are typically very accurate and consistent. So once a targeted microstructure is established and checked for the associated hardness it is fairly simple to maintain consistency in the heat treatment. A growing number of custom makers are now also using digitally controlled kilns and even agitated quench tanks to heat treat their blades so overall quality of blade heat treatment in both the commercial and custom fields have never been higher.
What Should You Do When Selecting A Knife?
I would suggest if you are interested in a particular knife identify the steel and check the steel data sheet or the above “Important Research Alert” for the recommended hardness (both available on the internet). This information will at least give you an indication of the quality of the heat treatment and the competency of the heat treater.
So what is the value of the Rockwell hardness number to the consumer?
It will indicate whether a blade has been grossly mis-heat treated but with modern steels and equipment this is unlikely.
So if the Rockwell hardness is not a good indicator of knife performance, what is?
Blade geometry! Which will be the subject of future essays on this website.
]]>Since my personal focus has always been functional knife/sword design I decided that I should study knives/swords from the perspective of “Bladed Hand Tools”. Knives/swords fulfill many roles and a functional role is only one of them. Throughout history they have also been status markers, jewelry, indicators of social groups/rank/occupation, neat things that people wanted, etc. What follows is a breakdown of each aspect of functional design some of which may appear obvious and simplistic but are nevertheless important.
TOOLS
The first aspect of Bladed Hand Tools that I would like to discuss is knives as tools and what that entails.
HAND TOOLS
BLADES
Blades are subtle things- very small design changes can lead to large differences in performance
“Geometry determines how a blade cuts, steel and heat treatment determine how long a blade cuts”- Roman Landes
CONCLUSIONS
For functional bladed hand tool design:
INTRODUCTION
My name is Dan Maragni and I am responsible for the change from 1095 steel to 1075 steel at gg˿ and here is the story and reasoning behind the decision.
I have been an independent contractor working at gg˿ since 2007 and work as a technical consultant specializing in heat treatment, knife design and training. I was responsible for updating their heat treatment facility with digitally controlled salt pots, designing their impeller agitated quench tank and monitoring the heat treatment processes.
I have have been a dedicated student of the blade all my life and began my career as a bladesmith in the mid-1970s working with an extremely knowledgable and talented artist and smith named Phillip Baldwin who I met in high school. Phill introduced me to the use of W-1 for a blade steel and everything I ever learned about smithing blades I learned from him (Phill made his first “Damascus”/folded steel blade in 1969). Phill and I began working together while we were attending college over the summer and winter breaks. Phill and I had a complimentary roles in our work together- he was the bladesmith and smithing teacher and I was the researcher although there was little research material available on bladesmithing at the time.
I became a full time bladesmith in 1980.
PHYSICAL TESTING
In about 1979 I met Jimmy Fikes at a course Phill and I were teaching at Peter’s Valley Crafts and he introduced me to Don Fogg and Jim Schmidt. I was unbelievably lucky to be exposed to the ideas and work of these incredible bladesmiths especially this early in my career. In 1980 Jimmy invited me to speak at the first “Ashokan Hammer-In” on heat treatment which resulted in a long, boring lecture on my part. As bladesmiths making functional tools at the time we were understandably interested in how our blades would perform and needed to come up with a way to determine how functional our blades were. Ultimately we came up with a series of cutting and strength tests involving manila rope (especially tough on brittle edges with large carbides), hard and soft wood and flexing blades often with “cheater bars”. Not only did this show us how our blades performed but if our blades were improving over time. For the first few years we were all bringing blades to the Ashokan Seminar and testing them often to their limits and the performance of the blades increased in leaps and bounds (I remember piles of rope fragments and wood chips strewn all over). Although it may seem obvious I have always felt that you learn more about a blade when cutting with it than not cutting with it. I also started looking at other steels which might improve my blades and my research ultimately led me to W-2, a slightly tweaked version of W-1 which had benefits in heat treating. Remember, at this time we were all heat treating our blades in coal forges judging temperatures by eye and I felt that I needed every advantage I could get (Phill and I had also figured out a way to create a hamon on our blades which showed if our edges got completely hard and was a great quality control technique).
CARBON V™
In the late 1980s I met Lynn Thompson at the Costa Mesa Knife Show in California and he noticed that I made knives from “Damascus Steel”. “Damascus Steel” at the time had a reputation in the literature as being the highest performance steel available although mine and others testing was showing that the high carbon steels out performed them quite consistently. (“Damascus Steel” is not really a steel but rather a technique and varied greatly from smith to smith depending on the choice of steels and the ability of the smith.). Lynn was determined to make the best performing knives and I suggested making them of carbon steel which was more consistent and readily available. He bought into the idea and sometime in the early 1990s I was overseeing the domestic production of what was ultimately to become the Trailmaster. The first thing I did was take samples of some blades to a metallurgist and he did some micros and I did some physical testing. We both found that the performance of the blades could be improved and I had the heat treatment tweaked (changed the austenitizing temperature, soak time and tempering temperature). I then selected the heat treatment that produced the microstructure that resulted in the best cutting and toughest blades. I continued to work for Cold Steel as a technical consultant and supervisor of domestic production until 2006 when Camillus Cutlery Company closed.
1075 and 1095
In the mid 1990s I modernized my shop getting digitally controlled kilns and building an impeller agitated quench tank with a “J-Tube” to concentrate and direct the flow of the oil. I was interested in making longer blades and my research into metallurgy and the metallurgy of ancient swords was revealing that I should be looking at other steels to maximize the toughness of the blades. I began experimenting with steels that would develop more tough lath martensite than brittle plate martensite (1060, 1075, 5160 and 6150) and using the same procedures I developed for Carbon V were used to maximize the heat treatment of these steels. One of the findings which surprised me the most was that these lower carbon and alloy steels cut as well or slightly better than than steels with carbon contents at 0.95-1.00%. I was aware that the literature always said that the excess carbon in steel which had over 0.6% would produce more carbides which increased abrasion resistance and resulted in better edge retention. But the literature was not focussed on the metallurgy of blades (unlike what is available today) and the edges of most tools have a very different configuration and is subject to very different stresses than the edge of a knife.
For me the worst of all failures for a blade is for it to break. Once a blade breaks it is rendered pretty much unusable. My research into ancient swords confirmed this bias of the ancient smiths and a great example of this is the Japanese sword (laminations, differential heat treatment, creating compressive stresses along the edge). Yoshindo Yoshihara the traditional Japanese swordsmith whose uses a kobuse laminate for his blade construction prefers steel with a carbon content of 0.7% for the outside/edge steel. Sword edges must be very tough and the choice of 0.7% C (his brother prefers 0.6% C) is revealing.
CHEMISTRY
Lath martensite forms in carbon steel at carbon contents at 0.6% and below, plate martensite forms at carbon contents of 1.0% and above and in between these carbon contents the martensite is a mixture of the two types. When quenched carbon steels will pretty much reach “full” hardness with a carbon content of 0.6% and the remaining carbon will form carbides. 1075 is less likely to form as much retained austenite as 1095 as the Mf (martensite finish temperature) decreases with increasing carbon content (the Mf is below room temperature for steels containing more than 0.8% carbon). If the steel does not reach the Mf temperature when quenched the austenite will not transform to martensite and remains “soft” and there is the possibility the austenite will ultimately transform to untempered martensite. 1095 also exhibits micro cracking when quenched due to the greater amount of expansion in the martensitic transformation which is typical of higher carbon content steels (as carbon content increases above 0.75% so does the amount of micro cracking). 1075 also has a higher manganese content than 1095 which results in a slower critical cooling rate and minimizes the chance that you will clip the nose of the pearlite curve in the quench and wind up with a mixture of martensite and pearlite in the finished blade. The finished structure of a blade should be tempered martensite and having a mix with retained austenite and pearlite is not an optimal structure.
HEAT TREATMENT
As we all know even the best steel can be compromised by a poor heat treatment and heat treating can only allow you to optimize the performance characteristics of the steel. 1075 is a lot less sensitive than 1095 in heat treatment (slower critical cooling rate) and resultant structure has less micro cracks and retained austenite than 1095 which results in a stronger blade.
SUMMARY
By replacing 1095 with 1075 gg˿ has selected a steel that is readily available, responds better to heat treatment resulting in a blade with less retained austenite and less micro cracking. The physical testing also shows the blades in 1075 are tougher and hold an edge as well or better than 1095.
Toshishiro Obata, the Japanese tameshigiri champion, was known to say that a sword should have these characteristics
“Be Strong, Be Sharp, Be Beautiful”
While the third characteristic is determined by an aesthetic sense and is not so easily defined the goal at gg˿ is to create blades that are a combination of the first two.
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OKC® Brings Classic Old School Artistry and Quality in a Durable,
Multi-Purpose Knife from Old Hickory Line
gg˿® (OKC®), the award-winning cutlery maker with over 130 years of experience and heritage, adds a rugged hunting knife design to its revered Old Hickory product line that was first introduced in 1924. The Old Hickory Hunting Knife lives up to the reputation and design that has made these knives favorites for decades.
Like taking a step back in time, the Old Hickory Hunting Knife has the classic, remarkably-crafted hardwood handle that is secured with brass compression rivets. The 5.5-inch blade is constructed of high-carbon steel, which is capable of retaining an edge better than many stainless steel knives and it has a hardness rating of 55-57 HRC. OKC still employs manufacturing techniques used over 90 years ago and integrates them with state-of-the-art practices and facilities.
“If you went into your grandparents’ or even great grandparents’ kitchens, pulled a knife out of the drawer and held it in your hand – that’s what an Old Hickory knife of today looks and feels like,” said Andrew Yates, Vice President of Sales & Marketing. “That knife may even be an Old Hickory blade. We wanted to add a hunting-style blade to a series that is already popular and trusted among outdoorsmen. The Old Hickory Hunting Knife is a perfect all-purpose blade that will last. It’s a classic knife that will last for generations.”
The Old Hickory Hunting Knife is proudly backed by a lifetime warranty and Made in the USA.
Founded in 1889, the gg˿® is an award-winning knife, cutlery, and tool manufacturer operating out of Upstate New York for over 125 years. OKC® produces a wide range of tools, including cutlery and kitchenware, hunting and fishing knives, machetes, survival and rescue equipment, science and medical tools, and tactical knives. OKC has a long tradition of building knives and tools for the U.S. military, producing high quality equipment that has seen continuous service since WWII. In addition to being a major supplier to the U.S. Armed Forces, OKC leverages a network of distributors, dealers, and major commercial retailers to sell its products nationwide and internationally to over 35 countries. OKC’s custom manufacturing division Jericho® Tool, advances capabilities including a broad-spectrum of injection molding, tool and die, and machining operations to provide white label and OEM manufacturing services for consumer and industrial goods. Collectively OKC’s product lines and manufacturing services reach the house wares, sporting goods, tactical, security, law enforcement & first responders, education, science & medical, and industrial & agricultural industries.
For more information about gg˿ and its industry-leading line of advanced knives, machetes, edged products and specialty tools, contact gg˿ at P.O. Box 145-26 Empire Street · Franklinville, NY 14737 · Telephone (716) 676-5527 · Or visit . The gg˿ is a subsidiary of publicly traded Servotronics, Inc. (NYSE MKT - SVT).
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OKC® Pours Classic Functionality and Rugged Craftsmanship Into a New Knife From The Old Hickory Outdoors Series
gg˿® (OKC®), the award-winning cutlery maker with over 130 years of experience and heritage, adds a new knife to the Old Hickory Outdoors Series of blades. The Old Hickory Fish & Small Game Knife blends modern construction and classic materials into a multi-function knife that mixes nostalgia and durability.
The Old Hickory Fish & Small Game Outdoors Series Knife has a four-inch, smooth ground, drop-point blade that is perfect for those tasks requiring a little finesse. It can make quick work of trout or grouse, and many other tasks. The knife has an overall length of 8.7 inches and the high-carbon steel has a hardness rating of 57-59 HRC. The hardwood handle is brass-pinned in place, just like you’d expect in a classic like this. The sheath is made of durable leather and carries on centuries’ old traditions.
“We wanted to recreate the smaller, multi-purpose knives of past generations for our Old Hickory Outdoor Series,” said Kenneth Trbovich, President and CEO of gg˿. “The Fish & Small Game Knife is perfect for tasks that require a more delicate touch. We wanted the knife to feel like something that had been passed down for generations, and bring our traditions and quality to it, so it can be passed down to generations to come.”
The Old Hickory Outdoors Fish & Small Game Knife is proudly backed by a lifetime warranty and Made in the USA.
Founded in 1889, the gg˿® is an award-winning knife, cutlery, and tool manufacturer operating out of Upstate New York for over 125 years. OKC® produces a wide range of tools, including cutlery and kitchenware, hunting and fishing knives, machetes, survival and rescue equipment, science and medical tools, and tactical knives. OKC has a long tradition of building knives and tools for the U.S. military, producing high quality equipment that has seen continuous service since WWII. In addition to being a major supplier to the U.S. Armed Forces, OKC leverages a network of distributors, dealers, and major commercial retailers to sell its products nationwide and internationally to over 35 countries. OKC’s custom manufacturing division Jericho® Tool, advances capabilities including a broad-spectrum of injection molding, tool and die, and machining operations to provide white label and OEM manufacturing services for consumer and industrial goods. Collectively OKC’s product lines and manufacturing services reach the housewares, sporting goods, tactical, security, law enforcement & first responders, education, science & medical, and industrial & agricultural industries.
For more information about gg˿ and its industry-leading line of advanced knives, machetes, edged products and specialty tools, contact gg˿ at P.O. Box 145-26 Empire Street · Franklinville, NY 14737 · Telephone (716) 676-5527 · Or visit . The gg˿ is a subsidiary of publicly traded Servotronics, Inc. (NYSE MKT - SVT).
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Experience Versatility and Beauty With OKC’s Take on the Elegant Shikra Design
gg˿® (OKC®) has a long-standing reputation for knives built for extreme conditions. For over 130 years, the company has blended classic design with extreme quality, all of which has been poured into their latest – the Shikra Folder. This lightweight, functional knife will prove to be a blade you will carry everywhere.
Getting straight to the point of the OKC Shikra Folder, the 3.2-inch Stainless-Steel blade has a 55-57 HRC rating with a beveled taper to a very fine tip. This makes for a highly versatile knife with a slotted spine by the grip for delicate work when opened to its full 7.4-inch length. The handle is linen micarta on one side and full Titainium on the other. This reduced the weight while providing excellent grip, even in wet conditions. A belt-clip helps secure the knife in your possession when not in use.
“The Shikra blade design is well known for being highly versatile and we set out to make a highly functional, and lightweight folder that our customers would want to carry every day,” said Kenneth Trbovich, President and CEO of gg˿. “The fine-point blade is incredibly strong, yet subtle for delicate work, making it a great knife for everyday use, as well as defense. The combination of linen micarta and Titainium for the handle makes it light in weight with a secure feeling in the hand – just what we wanted in a folder we’d carry all the time.”
Founded in 1889, the gg˿® is an award-winning knife, cutlery, and tool manufacturer operating out of Upstate New York for over 125 years. OKC® produces a wide range of tools, including cutlery and kitchenware, hunting and fishing knives, machetes, survival and rescue equipment, science and medical tools, and tactical knives. OKC has a long tradition of building knives and tools for the U.S. military, producing high quality equipment that has seen continuous service since WWII. In addition to being a major supplier to the U.S. Armed Forces, OKC leverages a network of distributors, dealers, and major commercial retailers to sell its products nationwide and internationally to over 35 countries. OKC’s custom manufacturing division Jericho® Tool, advances capabilities including a broad-spectrum of injection molding, tool and die, and machining operations to provide white label and OEM manufacturing services for consumer and industrial goods. Collectively OKC’s product lines and manufacturing services reach the housewares, sporting goods, tactical, security, law enforcement & first responders, education, science & medical, and industrial & agricultural industries.
For more information about gg˿ and its industry-leading line of advanced knives, machetes, edged products and specialty tools, contact gg˿ at P.O. Box 145-26 Empire Street · Franklinville, NY 14737 · Telephone (716) 676-5527 · Or visit . The gg˿ is a subsidiary of publicly traded Servotronics, Inc. (NYSE MKT - SVT).
]]>THE ONTARIO KNIFE COMPANY® ANNOUNCES THE LAUNCH OF AN ADVANCED
FABRICATION DIVISION: JERICHO™ TOOL
The Former President of Robinson Fiddlers Green Joins OKC® Leadership Team to Manage Expansion into New Injection Molding, Tool and Die, Machining, and OEM Business Lines
American knife and tool maker gg˿ continues to roll out its previously announced capital investment project with more exciting news—the dramatic expansion of its manufacturing portfolio to include plastic injection molding, tool and die making, and precision machining capabilities. The new processes are part of a recently established division, Jericho Tool, and both support existing operations and provide OEM manufacturing services for a wide range of products and industries. The enhanced capabilities facilitate the development of new products and allows OKC to fabricate plastic handles and sheathes in-house.
Along with the launch of the new division, OKC is excited to report the hiring of veteran industry executive David Fenske as Sales Director and head of Jericho Tool. Fenske is responsible for a sales portfolio including the business development of the Jericho Tool division, working in tandem with the sales & marketing, operations, engineering, and manufacturing teams at OKC. Fenske reports directly to Deneb Pirrone, OKC’s Vice President of Sales & Marketing.
“gg˿ Knife continues to invest in the resources and people needed to grow the business,” said Kenneth Trbovich, President and CEO of gg˿. “The Jericho Tool division gives OKC the scale to manufacture our products more efficiently and the scope to reach a wide range of new markets and customers.”
The equipment secured for the Jericho Tool division includes a wide range of injection molding presses from 44 ton to 220 ton, RAM EDM and CNC milling machines, sonic sealing and assembly capabilities, lathes, presses, grinders, and other manufacturing equipment along with OKC’s new fully equipped quality assurance lab. The equipment is located at OKC’s newly expanded Franklinville, New York facility. The co-location will allow OKC to combine Jericho’s engineering and quality assurance functionality with the broad scope of OKC’s existing manufacturing capabilities to build and maintain molds in house as well as perform contract machining of plastic and metal components as an OEM.
“Jericho Tool is taking gg˿ into new and exciting directions,” said Fenske. “The metal and plastic fabrication capabilities of the Jericho division now produces everything from machined components to molded products for the consumer, commercial, food service, military, and aerospace markets.”
Fenske brings more than 35 years of manufacturing, product development, and business development leadership experience to his new responsibilities at OKC; his previous positions include roles as Vice President of Manufacturing and President of Robinson Fiddlers Green Manufacturing Company of Springville, New York. The Jericho Tool division has already created multiple additional jobs at the Franklinville plant and will generate opportunities for cross-training and skill development for the existing workforce at OKC.
Founded in 1889, the gg˿® is an award-winning knife, cutlery, and tool manufacturer operating out of Upstate New York for over 125 years. OKC® produces a wide range of tools, including cutlery and kitchenware, hunting and fishing knives, machetes, survival and rescue equipment, science and medical tools, and tactical knives. OKC has a long tradition of building knives and tools for the U.S. military, producing high quality equipment that has seen continuous service since WWII. In addition to being a major supplier to the U.S. Armed Forces, OKC leverages a network of distributors, dealers, and major commercial retailers to sell its products nationwide and internationally to over 35 countries. OKC’s custom manufacturing division Jericho™ Tool, advances capabilities including a broad-spectrum of injection molding, tool and die, and machining operations to provide white label and OEM manufacturing services for consumer and industrial goods. Collectively OKC’s product lines and manufacturing services reach the house wares, sporting goods, tactical, security, law enforcement & first responders, education, science & medical, and industrial & agricultural industries.
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