Grain of steel in a sheet

J

John L

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Oct 28, 2004
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If you are cutting blanks from a sheet of steel is it necessary to cut with the blade parallel to the long side or is steel realtively grainless....unlike wood? Thanks
 
This is a subject that isn't discussed much, although maybe it should be. As I understand it, there is a linear grain alignment after steel has been rolled or otherwise drawn out, that creates a strength axis much like that in a piece of lumber. If this is true then there is some benefit to cutting blanks in a lengthwise orientation. Whether it makes a considerable difference, I don't know.
 
This is a good question that comes up from time to time. The standard answer is yes, it matters, it should be cut with the blade length running the same direction of the grain of the sheet.

However, there is a counter argument that says that edge retention is better, though blade strength is lower, with the grain run perpendicular to the edge.

There is a counter counter argument that says it is all moot. Unlike sheet metal fabrications and other work on metal that will not be heat treated, the elongated grain bias is erased in the steel once it is heat treated. The only artifact remaining is inclusions and certain carbides, which in most cases is largely irrelevant.

There are probably subtle pluses and minuses, but unless it is a blade that falls to one extreme or the other (extreme chopper, extreme slicer), I'd suggest cut it the direction that maximizes yield.
 
Steel grain has a shape more like an egg than as elongated as most believe. A blade is slightly stronger running with the grain, but only a marginal amount in reality.
 
Years back, I was able to get a sheet 2" X 2" of ATS34. I decided to see if I could find a difference. The blades were cut both ways and marked. They were all sent to the same reliable heat treating company that used a vacuum chamber and the deep freezing process. The results were quite remarkable. My testing indicated 25% more cutting ability with the knives that were cut lengthwise with the steel. Frank.
 
This comes up in discussions from time to time, but most info given is conjecture or anecdotal.

From what I have actually read, and observed, the grain ( not really the right term) is totally erased as far as bladesmiths are concerned in HT. If you forge, I doubt a metallurgist could tell which way the sheet was oriented. As Nathan pointed out, the artifacts such as slag inclusions, and some hard to deal with carbide structures may remain to some degree, but this should not affect the blades performance in any way measurable. All this is ,of course, based on a full and complete HT, allowing enough time for all things to go into solution.

Since most blades are made from bar stock, the question of orientation is of no concern.
If a large sheet is used, it is the normal procedure to cut with the direction of the rollers, but it won't hurt if it is cut the other way either. If laser or water jet cutting, avoiding material waste is a far greater concern.
 
The inclusions and carbides make the difference. Take a look at the transverse impact strength of 154CM and CPM154. The CPM version is significantly better .The longitudinal impact strength is about the same for both.
CPM rocks ! I mean carbides !!
 
It was all probaly some fuke the way they turned out so different when the blade direction on the sheet change 90 degrees. Frank
 
Not sure why the difference was so pronounced, but your observations are real world experience, and worth considering.
 
mete said:
The CPM version is significantly better .CPM rocks ! I mean carbides !!
Click to expand...

All else being equal, I'll take a CPM or powder version of any steel over the "regular" stuff any day :thumbup:

Back on topic, it's a great question and great thread. Thanks guys!
 
I agree that CPM is the way to go.
I used to use ATS-34/154CM for all my stainess blades.I will never use them again after using CPM-154....same for D2 vs CPM-D2.
 
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