Are blades made from welded rods unique to Vniti?

Discussion in 'Armory - Q&A' started by AndI, Oct 31, 2018.

  1. AndI

    AndI Rookie

    Joined:
    Oct 19, 2018
    Messages:
    19
    Likes Received:
    2
    I've been researching different brands of blades and was fascinated by the history of Vniti blades and the reasons why they developed their technology, different from that of other blade vendors. The story behind, in case someone does not know (I learned about it this evening, after spending several hours searching the net), is that VNITI - which was a Russian acronym for Federal Research Institute of Technology - in the Soviet time, a giant research and development organization with multiple sites across the Soviet Union which was developing technology for making steel for tanks and artillery - was converted to a public company in the early 1990s, then was spun off, broken in pieces, and ended up as a small company in the suburbs of St-Petersburg, with about 150 employees, lack of funding, without well defined products, right in the middle of a major economic crisis. Russian Fencing association approached them with a request to develop blades for fencing which Russian fencers could afford. At that time, Russian currency was heavily devaluated. A $100 price tag of a western-made FIE blade was too high of a price for an average fencer. VNITI engineers thought it could be a good application for their expertise and tools. The task was to develop a FIE-certified blade, produced at a lowest possible cost from materials which they could get. In order to reduce the cost of processing, they used cold rolling - simply because this tool was available in-house. To reduce the cost of materials, they decided to use maraging steel for the blade or at least the top part of it, a cheap high carbon steel for the tang or perhaps the lower part of the blade, and weld them together. Magaring steel was picked from the steels available on the market - not the top of the line, but close to it (about one or two steps down) - an "off-the-shelf" type of maraging steel usually used for heavy duty machinery - axes, gears, rotors of helicopters, parts of submarines, etc. The steel they used is similar to grade 300 US maraging steel. Likewise, they picked a common cheap high carbon steel which was easy to get in rods. It was basically like tinkering in one's garage: grab what is available, try to make something out of it. The difficult part was to create a strong welded connection. This, essentially, became the essence of their patent which describes in details the technology used to make their blades. The patent even specifies the steel which they use.They start with two rods, about 12-13 mm in diameter, and weld them together into one longer rod (actually, in the patent, they describe the method of welding three rods, maraging steel rod in the center and two high carbon steel at both ends, to make two blades from it in one pass). Next, they would carefully cold-roll the welded area(s). They learned, through trial and error (and failed initial attempt to get FIE certification) that there should be a certain, relatively small level of compression and deformation during the initial rolling of the welded area, to make the welded connection very strong and avoid cracks and breaking at the seam during bending of the blade. Once this is done and welded area is strengthened through cold rolling, they would cold-roll the whole rod in multiple passes until the blade takes the desired shape and dimensions. The patent has all those details, including parameters of cold rolling.

    Another part of processing, which can easily be a part of the reason for durability of their blades, is that they bake cold-rolled blades at 480 C for 9 hours followed by air cool. This is an additional martenistic aging step. Martenistic aging is typically 820C for 30 min to an hour followed by air cool and additional bake at 480 C for 3 hours. This is done to create a dispersion of tiny intermetallic (Ni, Cr, Mo, Ti, Al) clusters along existing dislocations and in the bulk. This arrests propagation of dislocations, thus decreasing likelihood of propagation of dislocations and subsequent breakage. This is how maraging steel can withstand so many bends without breakage, as opposed to high carbon steel, where carbon is added for strength but is not nearly as efficient in trapping dislocations. This is very similar to impact of oxygen precipitates (BMDs) on hardness of semiconductor grade silicon wafers and their resistance to slip during processing.

    With this ingenious value engineering, they were able to achieve the manufacturing cost of $20 to $22 per blade... to only learn how hard it is to penetrate the Western markets to sell their capacity of close to 10k blades per year (the Russian market was not large enough for their capacity). They fought for several years with their European (German) distributor, very well known company which I am hesitant to name here - but it is all in the internet! - who was their first distributor outside of Russia, to get paid $30 per blade wholesale, and went as far in this battle as threatening to dump the price to $15, below the manufacturing cost, and flood the market with ultra-cheap FIE blades (It is amazing how much interesting information one can find in Google...). VNITI could not make a lot of money by selling several thousands of blades per year in Europe and in Russia while making literally just a couple of dollars per blade, until they became known and established themseves as a brand world-wide, so this side business did not prevent VNITI's bankruptcy in October of 2013. They still cannot get out of bankruptcy. The good news that a new trustee was appointed last week for the next 18 months, per court order. This means, for what it is worth, that they will stay in business for at least 18 more months. Even though their blades sell well now, blade making is not the primary business of VNITI. Their main business has always been designing large tools for building train cars or heavy machinery or developing manufacturing methods for steels. Evidently, it is still not profitable enough.

    I can only assume, without knowing for sure, that the technology developed and patented some 10 years ago is still used as it was described.

    Anyhow, I was looking at the Vniti blades and was trying to find where the welded area was. I found a consistent color transition pattern in two areas: one transition in about 1/2 to 3/4 inches from the tang, the second transition in about 2-3 inches from the tang, into the blade. This approximately coincides with the area where the blade starts tapering off. I took some pictures but have to figure out how to post them.

    The questions to which I could not find answers - but I hope someone on this forum knows - are:

    1) Is VNITI the only manufacturer which uses two different materials in the same blade, maraging steel welded with high carbon steel?

    2) High carbon steel used for the tang has a 3-4% lower density, i.e., lighter than maraging steel. Could this lead to a shift in center of mass and a heavier feel?

    3) Is it beneficial or detrimental that tang is made of high carbon steel (like non-FIE blades)? Does it make it easier to bend the tang, does it make it more brittle or, just the opposite, less likely to break than if it was made of maraging steel?

    4) Does anyone has an educated guess where the transition from high carbon to maraging steel really is? In theory, maraging steel is more or less stainless steel, so it should be less affected by rust and corrosion than the high carbon steel. Blades which were in use for a long time and which were partly neglected might start showing this. As I said, I see some color transitions consistent across multiple blades, about 1 to about 3 inches from tang into the blade, but I am not certain if they are indeed indicative of the area of transition from one type of steel to the other.
     
    Last edited: Oct 31, 2018
  2. Purple Fencer

    Purple Fencer Podium

    Joined:
    Jan 19, 2001
    Messages:
    16,361
    Likes Received:
    587
    Great info. The tech stuff is waaaaayyyy outside my wheelhouse, but perhaps the mechanical engineers here would have better answers.

    Mergs? Dwight??

    As for multiple parts in a blade, the only other one I can think of are the Leon Paul folded ones. The blade itself is folded and otherwise flat....the tang and angles part at the back is a separate piece that's brazed to the folded part.
     
  3. AndI

    AndI Rookie

    Joined:
    Oct 19, 2018
    Messages:
    19
    Likes Received:
    2
    If someone is interested - and skilled in using Google translate or able to read technical documents in Russian - below is the link to the Vniti patent which describes how their blades are made
    http://bd.patent.su/2174000-2174999/pat/servl/servlet8648.html

    VNITI's web site with a short history of the company and some pictures of what they used to develop (the site has not been updated since 2016)
    http://www.vniti.ru/about.html#

    Market report with the history of "electric foil" project (their first product was a foil, epee and sable were added later) from its inception which contains the commercial details which I partly described in my first post (and many more other interesting details):
    http://economics.studio/ekonomika-predpriyatiy/proekt-elektrorapiryi.html
    and
    http://economics.studio/ekonomika-predpriyatiy/proizvodstvo-smejnyih-izdeliy.html
    and
    http://economics.studio/ekonomika-predpriyatiy/problemyi-vliyayuschie-faktoryi51-proekt.html
     
    Last edited: Oct 31, 2018
  4. jkormann

    jkormann Podium

    Joined:
    Nov 8, 2002
    Messages:
    3,016
    Likes Received:
    205
    I'll say their blades are impressive, if not very flippy, but their tangs need A LOT to be desired.
     
  5. AndI

    AndI Rookie

    Joined:
    Oct 19, 2018
    Messages:
    19
    Likes Received:
    2
    jkormann, would you be so kind as to elaborate, please? What is that you do not like about their tangs?
     
  6. keropie

    keropie Podium

    Joined:
    Sep 10, 2005
    Messages:
    1,466
    Likes Received:
    172
    I've never had any issues with their blades (foil), including finding them plenty flexible. They are a bit heavier, and there are some blades I prefer for weight balance purposes, but I have a few Vniti in the bag pretty much always.
     
  7. jkormann

    jkormann Podium

    Joined:
    Nov 8, 2002
    Messages:
    3,016
    Likes Received:
    205
    On a hard flick, the tang broke. A local guy re-welded it and it's been fine. The blade is slightly taking a bend.
     
  8. Inquartata

    Inquartata Podium

    Joined:
    Jul 12, 2001
    Messages:
    36,818
    Likes Received:
    1,331
    Happens with some sabre blades as well---not only Vniti. Seems to happen more often to the ones whose owners like to put a "cant" in their weapons, but I've had one or two happen to me as well ( I like my blades straight so I do not cant them ).

    I have been told to take a round file and chamfer the sharp corners where the shoulders of the blade meet the round tang. I do it when I remember.
     
  9. brtech

    brtech Podium

    Joined:
    Nov 4, 2003
    Messages:
    2,378
    Likes Received:
    183
    Not at all an expert or even knowledgeable about history but I believe that maraging blades existed well before Vniti, and their blades need welded tangs in order to take a bend. I think most blades have welded tangs for the same reason.
     
  10. neevel

    neevel Armorer

    Joined:
    Jan 17, 2000
    Messages:
    3,358
    Likes Received:
    309
    They would have used maraging steel because that is what the FIE specifies for blades (Annex A to the material rules gives specs for the steel to be used in blades). For a while there were a few non-maraging blades that received homologation, but that was subsequently withdrawn.

    Welding a rod on for the tang is a fairly common thing- among other things, carbon steel is much easier to cut threads on.
     
  11. twisterfencing

    twisterfencing Podium

    Joined:
    Feb 10, 2006
    Messages:
    2,023
    Likes Received:
    235
    The only thing about this blade that is welded on is the tang.
    To be clear, there are only about 3 forges in the world that do not weld on tangs, due to the fact, its a tricky process to do and they did not want to attempt it??
    Vniti's are stamped. Don't know where the idea of adding welding rods came from??
    These blades start out from Gov't surplus to a melting pot to rods to blades and left over, back to melting pots.
     

Share This Page