420HC heat treat variation

S

Screaming Eagle

Joined
Dec 3, 2009
Messages
47
How much variation in quality is there in the heat treatment of 420HC? I've run across some 'other than Buck' American made knives that are sharp as the dickens out of the box. They're modeled exactly like an 872 Sandman and have the same steel as the 872.

I guess what I'm asking is 'do all American knife manufacturers tend to heat treat 420 the same'? If so, shouldn't the quality of the steel be the same (even if it's not Buck mfg.)?
 
Buck_110 said:
Steel quality is determined by the steel manufacturer(foundry).

Heat treating/tempering can vary quite a bit from one maker to another. It all depends on what the maker is striving for. A higher Rockwell hardness can result in better edge retention, while a lower hardness can result in a tougher blade. There is no hard and fast answer to your question. It's all a matter of give and take. Most makers will strive for middle ground to have the best of both worlds. Heat treating is an art with science involved, not the other way around.
Click to expand...

i would add to my friends info that 420 as well as all the '400' steels
that each foundry has their own 'secret formula's" for their version
so say that you had 420 HC from two diff foundry's
and Bos did the HT on them in the same batch..
each would most likely turn out diffrent!
 
So, each maker has it's own 'proprietary secret' (at least theoretically) for the steel they use? All 420 HC is not 420 HC in components?
 
Heat treating is the most important thing for both edge retention and corrosion resistance, during the heat treat process you are actually changing the physical properties of the steel, Paul's formular used at Buck maximizes these qualities in the steel. At Buck we believe this is of the highest importance, this is why we have invested so heavily in equipment and to employee the worlds best heat treater Paul Bos.

Many companies out-source their heat-treat to job shops [Good luck with that]
 
So, does Buck manufacture their own steel or is it manufactured elsewhere according to the specs that Buck provides for the blanks?

I saw one site that had the % of each component listed for 440C, 420HC etc. Are those just general ranges that 'qualify' as that particular 'type' of steel? Then the 'art' part of it is in the heat treating according to the proprietary 'secret' times and temps?
 
from time to time some one will post a list of what is in "x" steel
but some one else will see a diffrent list and dispute it..
ASME list of what is in each steel is a guide line not a
hard fast formula..
like any recipe there will be diffrences from each cook!

i do not know were buck gets their steel
some site said buck's 420HC has some 1 to 4 % differences in some additives..
and NO- HT is not an exalt science i dont belive..But the science of it is important !
like steel there are basics and ranges but
Bos has almost a half century of experience and research which is irreplaceable...
 
Buck manufactures no steel or specs. those are provided by the steel manufactures .
Yes, general ranges of elements and content for that steel . They try to hit it on the mark and usually get very close so, those can be taken as valid . Then the cooking of the steel is much like a chef guards his recipes . DM
 
Just out of curiousity, is there a 'decrease' in some of the components in the blanks and an 'increase' in others that result in the proper hardening under the prescribed heat? Maybe not the 'size' of the blank decreasing (physically overall) but in the rearrangement of the molecules? Some 'increase' while others 'decrease'?

I'm trying to get a 'picture' of this in my mind...
 
Eagle, As duck 57 posted, heat treating 'is' the rearranging of the steels molecules . Heat treating is done in three parts; high heat, cold (no heat) and low heat . Energy always changes a substance ie. a freezer will change water into another form, a solid . Then put the same water on a stove and apply heat and it changes into a vapor . Three forms of the same substance a liquid, solid and a gas . Heat treating steel is similiar . The chrome in a steel during heat treating (the use of energy) breaks down to form chromium carbides . A much harder compound than before it was heat treated . The molecules are broken down by energy and reattached to form a new substance . If vanadium is in the steel it forms vanadium carbides, very hard . Carbon the same thing and so forth . Hope this helps . DM
 
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