When mentioning tough knives, Dan Maragni should always come up. For those who say "Dan who?", Dan has been instrumental in advances in blade manufacture technology. He studied history, the blade makers, and blades to microscopic levels, studied metallic transformations during heat treating, conducted his own years long and ongoing experimentation, studied and taught to highest levels the art of forging blades. And what forging did, he pretty much managed to duplicate to the microscopic level in factory production blades using sophisticated heat treatments and quenches. He personally made several company lines legends in toughness and durability, in particular the early original Becker knives, as well as Cold Steel's Carbon V knives such as the original Trailmaster. And even the incredibly durable blade of the lowly Twistmaster in above post.

So, when you are ever considering a knife, and it turns out Dan Maragni was involved in the R&D, think on this, rather than say "Dan who?"...you will get a tough knife.
From his own bio.

EMPLOYMENT
1988-2006 Head of Domestic Production for Cold Steel, Inc. Brought Cold Steel production to Alcas Cutlery Corp., Ontario Knife Co, Western Cutlery and Camillus Cutlery Co. Duties included overseeing every step and operation used in the production of Cold Steel knives from metallurgical examination of the incoming material to final inspection and packing. Developed Carbon V material/heat treatment, modified and improved the heat treatment to Cold Steel standards, established procedures and trained sharpeners. My position ended with the collapse of Camillus Cutlery Co. in June 2006.
1982-2006 Technical consultant to Cold Steel Inc.
1979-1988 Custom bladesmith specializing in high carbon, performance oriented knives. American Bladesmith Society Mastersmith rating and Voting Member of the Knifemakers Guild 1983-2003.

TEACHING
2005, 2000 and 1995-Founded, organized, directed, demonstrated and 
lectured at the NEBG Ashokan Sword Seminars. Lectures included “Introduction to Swords”, “European Sword Technology”, “Physical Characteristics of European Cutting Swords 250 BC to 1200 AD”, “Medieval Sword Reconstruction” and “Violent, Bloody Death” a look at forensic archeology associated with edged weapons.
2003 Lectured on “Development of Blade Patterns from Laminated and Twisted Structures” and demonstrated pattern development using Fimo clay at the annual Timonium Ethnographic Seminar.
2003 Lecture/Slide Show “From the Celts to the Normans: Early Sword Development in Europe” and demonstrated European swordsmithing at the Association for Renaissance Martial Arts 2003 International Gathering in Sandy Creek, NY.
2003 Lecture/Slide Show on “Celtic Art” at Mohawk Valley Community College as part of the visiting lecturers series.
2002 Lectured and demonstrated at the ARMA Princeton Seminar on “What is a Real Sword”.
1976-1996 Taught Bladesmithing classes at Naples Mill School of Arts and Crafts, Peter’s Valley Crafts, Brookfield Craft Center and Penland School of Crafts.
1991-1994 Lectured on “Fighting Knife Design Concepts” and “Beating the Edged Weapon Paradox: Blade Construction Techniques Throughout Time and the World” at the Northeast Martial Arts Conference.
1983-1994 Organized, directed, demonstrated and lectured at the New England Bladesmiths Guild Ashokan Seminar.
1990, 1993 Demonstrated “Blade Forging and Heat Treatment” and lectured on “Basic Metallurgy” and “How Every Sword was Ever Made in Any Time and Any Place” at the Artist Blacksmith Association of North America Conferences.
1990-1992 Lectured on “Evolution of the Japanese Sword from the Kofun/Nara to the Edo Period”, “Evolution of Japanese Weapons and Warfare from the Kofun/Nara to the Edo Period” and “Functional Fighting Knife Design Concepts” at the annual Zen Do Kai Seminars in Cazenovia, NY.
1980-1982 Demonstrated blade forging and lectured on heat treatment at the NEBG Ashokan Seminar. Founding member of the NEBG.

PROFESSIONAL DEVELOPMENT
1996-2007 Built a prototype commercial heat treatment set up using digitally controlled furnaces and an agitated oil quench. I have been running experiments with a variety of carbon and alloy steels and making and testing blades of these materials. All these experiments and processes are documented and metallurgically examined by Metallurgical Consulting, Marcellus, NY.
1998 Research trip to Europe (Italy, Switzerland, Germany and England) with Dr. Lee Jones. Examined swords from the Celtic period through the Renaissance in museums and private collections.
1996 Research trip to England with noted arms collector and co-author of “Swords of the Viking Age” Dr. Lee Jones. Examined swords in museums and private collections and met with international arms authority and author Mr. Ewart Oakshotte.
1993 Research trip to Japan. Met with Mr. Takuo Onoue, prefectual metallurgist and Japanese swordexpert and swordsmith Mr. Kanemasa Oono.
1993 Completed Level One of the ASM Heat Treating Certificate of Achievement Program.
1992 ASM Course at Materials Park, Ohio “Heat Treating and Quenchant Techology” with Dr. George Totten and Dr. Charles Bates.
1991 Completed ASM Local Chapter Course “Stainless Steels”.
1988 Completed ASM Local Chapter Course “Metallurgy for the Non-Metallurgist”.
1985-1992 Studied Kali, Muay Thai and Jun Fun Kung Fu with Sifu Kevin Seaman.
1969-1971 Studied Three Weapon Classical Fencing with Maestro Oscar Kolombatovitch.

PROFESSIONAL MEMBERSHIPS
American Bladesmiths Society- Mastersmith Rating- 1983-2003
Artist-Blacksmith’s Association of North America
American Society of Materials International
Japanese Sword Society of the United States
Knifemakers Guild- Voting Member- 1983-2003
The Historical Metallurgical Society


Although not a folder, the short following clip is the result of AGR using the out of print Sharon 0170-6 steel and having it treated under Dan's supervision. Note this is not the normal filmed cinder block, but a true construction grade 40lb block, and every strike is max effort, and aimed only at corners of the block, using only the edge of the blade, guaranteed to wreck most knives. https://www.youtube.com/watch?v=RDSOwkXxlGE