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Post by john1 on Jan 28, 2019 17:29:34 GMT
Anybody know if any/which Chinese forges actually: 1. Normalize their katana blades before hardening them 2. Heat the blades evenly (as opposed to piling them into the forge in a heap), 3. Reject warped blades (rather than just hammering them straight after tempering - adding all sorts of stress risers) ?
I’m hoping at least a few of the forges suspend their blades 1” apart in a molten salt pool or oven to normalize, harden, and temper them. Are there any ?
Also, does going up in price with Hanwei and Longquan forges get you a better heat treat ? Ie: 1st world heat treating equipment, or an individual doing each operation seperately, sword by sword. Or does more cost just buy better components, polishing and assembly ?
Or are the heat treats from Hanwei, Feilong, Huawei, Dynasty Forge, Munetoshi, and Sinosword all pretty great already ? Ie: At least as good as a knowledgeable enthusiast trying to do a good job in a garage forge could do ?
Thanks.
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Post by shobutengu on Jan 28, 2019 19:30:11 GMT
you get what you paid for when it comes to these Chinese forge and sometimes luck play a role into too. i don't think these forges give the best heat treatment in terms of maximizing the quality and benefits of the steel but if they do that it will drastic increase the price-point of the products they're selling . but they give a functional blade that works for it's intend targets. it takes a long time and a lot of work for an individual smith to give the best heat treatment to his steel and because of those experience of the smith, the time ,and labor can cost a lot of money. sometimes you just got a take a chance but majority of the time you won't get a lemon when it comes to heat treatment from china . it won't be the best but it's usable .
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Post by Cottontail Customs on Jan 28, 2019 20:13:36 GMT
for the most part, unless you know the individual smiths and are familiar with their entire process, you have to go by results. Hanwei and many of the other Chinese forges have been producing well heat treated blades for a very long time and China does indeed have many very experienced and skilled smiths making quality blades. People have been cutting with these swords for years and while every large production operation will let out a few lemons here and there, which considering the overall number of blades some produce isn't surprising at all, they generally perform and hold up quite well. also consider how many of these blades are not only used but abused on a daily basis, cutting and surviving all sorts of target types, including materials that probably shouldn't be cut. if it looks, performs and endures like a well ht'd duck, it probably is.
there are a lot of things that separate these swords from nihonto and other top examples, most of which is the endless string of little details that really make for an amazing all around finished product but at the core, I have no doubt the Chinese made blades are forged and ht'd well enough. especially for the price. it can also depend on what you're looking for specifically, are you talking about breaking down the blade molecule by molecule to see how it stacks up against others or just interested in general functional comparison? when new to this hobby, it's best to go by user reviews and recommendations and reputation.
imo, what falls short most of the time is the koshirae, which on many examples seems just a cheap afterthought. higher prices don't necessarily reflect higher quality. when you get to know the individual smiths/sellers, you can start to see where some of the extra money goes and sometimes it is a difference of skill level. higher consistency, better geometry, koshirae/fittings and almost always, the quality level of the polish. polishing takes time and in some cases it could amount to almost half the total cost. in Hanwei's case, I would imagine a lot of the cost goes to the design, materials, execution, production, advertising, etc., in the end offering a much more well rounded and complete package, imho. this doesn't necessarily mean that the blades are heat treated better though.
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Post by john1 on Jan 28, 2019 22:25:30 GMT
Thanks. I’m definitely willing to pay for a higher quality heat treatment . I read one post from several years ago where someone said that Hanwei was the only forge that uses a thermocouple to control their forge temperature. I assume this means they were ensuring blades didn’t grow large grain structures while waiting for the smith to pull the next one from the pile. I hope that this means that Hanwei cares enough about grain structure that they also normalize the forged blades at least 1, preferably 2-3 cycles - and ensures the blades are heat treated consistently along their entire length - by ensuring they aren’t in a big pile during heat treat. The question is - do they ? Obviously, normalizing and keeping the blades sperated during heat treat costs more - what price range does it start at with Hanwei ? And - does Huawei, Feilong, Dynasty Forge, Munetoshi, and Sinosword also do it ? What price range ? Ie: Which Chinese katana brands/models should I pick from if my priority is good heat treat (1st), geometry (2nd), and everything else is 10th ? Can I order a custom blade from a Chinese forge and trust that it will “actually” be fully normalized if I pay extra ? Which forges ? ps: Unfortunately - Motohara, Citadel, MAS, and non-Chinese custom blades are beyond my current budget. Thanks for your help !
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Post by shobutengu on Jan 29, 2019 4:13:52 GMT
Thanks. I’m definitely willing to pay for a higher quality heat treatment . I read one post from several years ago where someone said that Hanwei was the only forge that uses a thermocouple to control their forge temperature. I assume this means they were ensuring blades didn’t grow large grain structures while waiting for the smith to pull the next one from the pile. I hope that this means that Hanwei cares enough about grain structure that they also normalize the forged blades at least 1, preferably 2-3 cycles - and ensures the blades are heat treated consistently along their entire length - by ensuring they aren’t in a big pile during heat treat. The question is - do they ? Obviously, normalizing and keeping the blades sperated during heat treat costs more - what price range does it start at with Hanwei ? And - does Huawei, Feilong, Dynasty Forge, Munetoshi, and Sinosword also do it ? What price range ? Ie: Which Chinese katana brands/models should I pick from if my priority is good heat treat (1st), geometry (2nd), and everything else is 10th ? Can I order a custom blade from a Chinese forge and trust that it will “actually” be fully normalized if I pay extra ? Which forges ? ps: Unfortunately - Motohara, Citadel, MAS, and non-Chinese custom blades are beyond my current budget. Thanks for your help ! The thing is .... you don’t know how they heat treat they’re blade or what types of heat treatment they use besides hardening. Most of the time they just use a coal or gas forge and heat the blade as evenly as possible to austenziting temperatures then plunge it into a water or oil quenchant. If you’re too worry about the heat treatment of Chinese forges then I advise to save up more money then. Hire a renown smith and get him to make you a blade. Or just stick with a brand that has been known to give consistency results with their heat treatment .
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Post by Cottontail Customs on Jan 29, 2019 4:24:08 GMT
honestly, there is no guarantee no matter how much you're willing to pay when it comes to this quality level. they could all be considered well heat treated and not well heat treated at the same time, kind of a Schrödinger's katana, so to speak. meaning, you will be taking a chance despite which one of them you choose but also stand a chance to receive a lifelong favorite cutter but won't really know until you put it to the test. all of the brands you named above, including st nihonto/Sheng and a few others with good reps, have been known to produce great swords with satisfactory heat treating so by sticking to this list, you are increasing your chances already.
there is a higher risk when buying from China dealers directly however, mostly due to having to send your katana back to China if you want a refund and it disappearing along the way. so it might be more advantageous if you're worried to buy from a more local source such as SnA, KOA, SBG, etc., who offers hassle free returns. the brands you named have all been around for a while and there have been a few cases of some ebay sellers refunding money without needing to receive the defective sword but probably something you shouldn't count on. I'm personally more familiar with Hanwei, Huawei, Feilong, DF and Munetoshi but I don't think I could guarantee that all of the swords ever made by them were all 100% spot on for heat treat. I don't cut a lot and I rarely push a blade beyond what it was meant to do so I really don't know if the blades I cut with and thought performed well were perfectly heat treated or just good enough not to show damage or issues. I guess what I'm saying is I don't know how many, including me, would even be able to detect small issues with ht just doing occasional, basic cutting.
if you're planning on really taking your blade to town on hard or abusive targets often or are a beginner and count on botching many cuts, maybe a oil quenched 9260 th blade is a better choice. these have a rep of being incredibly tough and resistant to bends, torques and sets and are typically less $ than dh blades. you can get a very good one from Huawei for under $200, shipped
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Post by shepherd214 on Jan 30, 2019 22:25:02 GMT
If you buy from an experienced, individual, custom maker then you can guarantee your blade will have a superior heat treat. You'll pay more, but it'll be worth it, far more than the Chinese forges because time and attention will be put into just your blade instead of a large batch.
If you plan on abusing the sword, as mentioned above go with a TH 9260 sword from a known vendor like Huawei, St Nihonto or Sinosword.
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Post by rayeknor on Feb 1, 2019 23:32:53 GMT
Hi,
I can attest that at least the Longquan forge SBG uses for their forge direct series heat treat their master smith forged blades properly.
To further emphasize this I will give you an embarrassing little episode I had with mine.
I bought a custom 33" katana last year (will post a review eventually, with some interesting mostly positive observations) and I'm not yet fully used to handle such a long blade that while cleaning it I suddenly heard a "THUNK!" sound.
In my carelessness while cleaning the blade near the habaki I lifted it up vertically to have a look and thrust the kissaki (tip) hard into the painted concrete roof. Letting go some high level swearing I feared the worst, but nothing but maybe a tiny tiny scratch on the tip.. edge and shape still pristine.
I felt the impact force in my wrist and was sure there was some damage maybe even breakage or cracking but no not at all. Makes me believe it when they say Chinese T10 steel got some tungsten in it.
Bit of a bruised ego and a little hole in my roof later coupled with handling the sword without such silly accidents I can only say the forge direct master smith blades are top of the line and a steal at the current price. Part of the handle construction and parts are not but that is a story for the eventual review.
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Post by William Swiger on Feb 2, 2019 0:52:02 GMT
Yeah - me as well. Years ago, I bought my first expensive katana from Hanwei. Was swinging it around in my best Highlander TV moves and hit the ceiling.....Broke the very end of the tip. Spent hours reprofiling the tip to make it look perfect. Being 6 feet, 4 inches aids in smacking things....lol
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addertooth
Member
Working the tsuka on two bare blades from Ninja-Katana, slow progress
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Post by addertooth on Feb 12, 2019 2:16:52 GMT
A little on heat-treat, from a guy that has actually done it. The Hamon tells you a lot. The bright Hamon line (Nie) is a particular heat treat product called pearlite. It represents a great boundary line, where as you move towards the edge you have Martensite (very hard), and as you move towards the Mune (back of the blade) you get softer steel. Simple observation of the Nie, and a quick test of how easily the edge is ground/abraded will tell you 95% of what you need to know about the heat treat. Most Chinese forges use simple steel (like T10 or 1095), it isn't like they are dealing with complex steels (like 154CM) which have a 15 degree window before the quench, or a cryo stage to make the steel turn out Okay. If the Nie does not run to the edge, and the edge is hard, you are probably just fine (assuming differential heat treat). It is not magic to heat treat, it only requires a focus on evenly heating the entire blade until the Curie point is reached.... followed by an even and balanced quench. I have only warped one blade ever, and it was messed up in the quench stage due to me not having a large enough quench tank for the length of the blade (the quench was uneven). With some basic attention to detail, 1095 is easy. I almost always brine-water quenched, which is a more brutal quench than oil quenching methods. If you want to see a real challenge factor, try to make some L6 Bainite, with molten salts for quenching (followed by a cryo treat)... you will realize just how easy 1095 is to get right. Normalization is a kewel step, but if geometry is good, and even heat has been used to raise the steel to the austenitic state (Curie point), followed by *even* rapid cooling in the quench, then the risk of warpage or deformation is minimized. On that show (Forged in Fire) where knife smiths compete, I only see about 1 in 8 of them take the time to normalize. The show almost never shows when they are actually tempering their blades (it is a boring off camera moment).
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Post by john1 on Feb 12, 2019 4:26:21 GMT
Thanks. I appreciate you sharing insights from your hands-on experience My understanding is that normalization also corrects any grain growth / large crystals that cause stress points in the blade. Ie: It eliminates hidden flaws that could cause the blade to break. However, I've never made a sword, so I may be overly concerned about something thats mostly a theoretical issue... Have you ever snapped a test-blade to check whether normalizing made any difference in how strong the blade was ? Also, assuming the Chinese forges use charcoal forges with a single air pipe in the middle - how likely is it that the blade is heated evenly ? In the longquan forge tour video on sbg, I saw a handful of blade blanks just sitting in the hot charcoal heating up, while one was being forged on the power hammer. My assumption, is that heat treat is similar - put a handful of blades in the forge, wait for them to get hot, and then quench them I by 1. I assume this would cause the middle of the blade to get much hotter than the end sections And either, the 1st few blades in the bunch to be under heated (and soft), or the last few blades to be overheated and have big crystalline grain (and break easily). Is this likely a good set of assumptions --- or is it "not that hard to do" even when trying to work in a production line setting John
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addertooth
Member
Working the tsuka on two bare blades from Ninja-Katana, slow progress
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Post by addertooth on Feb 12, 2019 13:17:26 GMT
I believe you have seized upon the word "normalize", without fully understanding its use as it applies to knives and swords. Where normalization is best used is in things like pipeline and pressure vessel steel, complex welded fittings and mixed products which involve elements which are cast and with parts that are welded to hit which are hot/cold rolled.
When working with products which will be mechanically stressed, you want your grain size to be consistent across the entire worked piece. This way you don't have hard brittle joints at the weld, and softer chewy steel adjacent to it. Without a process to make the entire piece equally hard/chewy, you create the risk the part may crack and break where the soft chewy steel is next to a hard/brittle steel. Cast iron tends to be hard/brittle, any place you weld at has taken the steel to the curie point, and the weld will be harder than the areas where the steel remained cool. Thought experiment, super glue is brittle, milk jugs are soft and chewy. Should you superglue two milk jugs together and then flex the jugs, the superglue joint will nearly always fail. If on the other hand you use a flexible adhesive, such as contact cement, the joint will survive the flexing.
In manufacturing, Normalization is important, as it makes all of the steel in an assembly, equally hard/chewy. It helps especially when you have a mixture of cast iron and sheet steel which have been welded together in an assembly. It helps when you have elements like tower sections or beams which have been welded together, as it eliminates localized hardness/brittleness at where the pieces were welded together.
The goal of normalization is to reduce the amount of martensitic (hard) steel, which may be highly localized in the piece. Normalizing makes the steel harder than annealed steel, but NOT knife or sword hard.
With knives and swords, frequently only the blade portion is heated, the handle is frequently not heated as much, as it needs less forging than the blade. Each time steel is heated cherry red, it "sweats" a bit of carbon... this reduces the amount of carbon available in the blade. Some people believe that heating the entire piece helps "redistribute" the remaining carbon more evenly in the blade, thus reducing sections which may be undesirably harder (due to higher remaining carbon concentration), than parts which got heated and forged more. Carbon migration in Austenitic (cherry red) steel does happen, but not at a high rate that some would suppose. And remember, each time you heat your steel to cherry red, some carbon is driven out.
But most importantly, on a classical differentially heat treated blade, the smith INTENTIONALLY creates a zone of hard martensitic steel (the edge, up to the pearlite line call the Hamon), a zone of Pearlite (the Hamon itself), and softer steel which is more akin to normalized steel (the area on the back/Mune of the blade). In other words, a classical katana is the exact opposite of Normalized steel with consistent grain size and structure. He achieves this by placing clay on the blade to slow the rate in which the steel is cooled during the quench. Rapid cooling causes more carbon to be trapped in the matrix of iron crystalline structure (causing a growth in size of that structure, and making it less flexible as the trapped carbon stiffens the cubic structure). This gives us the curve seen in a Katana, as the edge grows longer than the softer back of the blade which has less trapped carbon. The back of the blade has less carbon trapped in the iron matrix, as it has more time to "escape being trapped in the matrix due to slower cooling during the quench". And most importantly, the last heat treat cycle is the most important, as it defines the final state of the steel. I can anneal steel, and subsequently have a follow on cycle where it is hardened. The steel will only "remember" the last cycle which hardened it. It will not care it was previously annealed. This is part of the reason why normalizing does little for a blade, unless critical faults existed in it due to heavy localized heating of small sections..
I hope this helps.
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Post by john1 on Feb 16, 2019 12:30:01 GMT
Thanks Addertooth - that helps a lot Two last questions to make sure I understand correctly - 1. If a smith leaves a handful of sword blanks sitting in a forge to heat but shapes them one at a time- would this cause some of them to have brittle areas above the Hamon that remain after the final heat treat (unless the blade was normalized) ? 2. If the smith doesn’t normalize to prevent warpage, and hammers any warps straight right after the quench instead - does this cause weak spots in the blade ? Thanks for your help !
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addertooth
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Working the tsuka on two bare blades from Ninja-Katana, slow progress
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Post by addertooth on Feb 16, 2019 12:54:26 GMT
Number 1 has two elements to it, I will break each down. First of all, steel "sweats/loses" carbon the longer it is cherry red hot. So resting in the forge for extended periods of time can cause the carbon content to drop, making the blade less hard after the quench. The second element is that a piece of steel left in a forge too long may actually "burn" making the steel weak as an outcome. The second condition is avoidable by using an electric Kiln (as versus a gas or charcoal forge), which is set at the exact temperature you want the steel to reach.
Number 2 implies that not normalizing causes warpage. This is typically not the case. As long as the heat applied to raise the temperature of the blade is even and uniform (no hot spots and no cold spots), AND, the blade geometry is balanced, AND, the quench cools all of the surface in a uniform fashion, THEN warpage is normally not a problem. Attempting to cold-straighten a hardened blade is just a bad practice, as it introduces micro-fractures in the steel. The correct action is to toss the blade back into the forge, and try to do a better job evenly heating the blade and evenly quenching the blade.
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Post by john1 on Feb 18, 2019 3:01:46 GMT
Thanks for all your help - It sounds like many of my worries about the heat treat for mass produced blades was based on faulty assumptions
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Post by Deleted on Feb 20, 2019 0:48:53 GMT
Hanwei had a factory fire just about eight years ago. Even up to then, a fairly up to date state of the art approach more thorough than some. It was in the following years of growth that CAS became top cheese producer, using Hanwei's ability to add the old (and revamped) CAS medieval models and some other lines. I don't think you can look at the Hanwei factory as having absolutes because different products may dictate different processes. Say, of their through hardened blades vs differential hardening. There are some very old articles regarding Hanwei but they hardly reflect what it is now. Bugei is stepping down and they were assigned different shop space and workers. Some of those premium mainline Hanwei production swords started to show similar technique and care. The Bugei swords were not just re-branded production level models with flashy hub caps. Some videos are old as the hills and one may grasp some misconceptions regarding many sources. A few months on the ground might make for a good article but who's financing such a journey. Paul visiting one shop is only scratching the surface of the combined business. Fred Chen, spurred and taught partly by Rick Barret, had then spawned a host of apprentices then setting up their own businesses. See Huanuo, Dynasty forge and other histories wherein. I don't know if Albion is still heat treating blades one at a time but one could hope some Chinese makers actually take the time and charge accordingly. Here is one such. www.swordforum.com/vb4/showthread.php?91862-HandMade-Real-HandMade-Katana-SwordAlso a decade ago but consider how some still approach swordmaking. Lots of stuff no more than dust on the winds now. at least two generations removed from the beginnings of usable Chinese made katana for the world market.
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Post by alexhuatian on Feb 26, 2019 2:04:49 GMT
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