Question about replacement plane irons?

Re: Question about replacement plane irons?

ThomD

>I don't personally like A2. In carbon, I find both of those brands about the same, maybe 1% advantage to LN. In practice I buy them based on whether they make the kind of blade I want. Brass rod tests and such show that O1 has better resistance to bending at the edge, which is what planing does. However, a lot of people seem to be buying A2, so you won't be alone.

Re: Question about replacement plane irons?

Jeff Heath

>I've replaced the old Stanley blades and chip breakers on my Bedrocks (several) with Hock blades and chipbreakers with very good results. I have both cryo and high carbon (what was available at Woodcraft at the time of purchase) and am very pleased with both. I use my planes daily, and I can't tell the difference once they're sharpened. I will say that the Hock blades required more work (flattening the backs) than my LN plane blades did.

Jeff

Re: Question about replacement plane irons?

mikew

>Hi John,

I have used both as Thom, and as he, also like the HC versions. Mainly due to a decrease in honing and I like the feel of the HC when honing.

Take care, Mike

It is all about abrasion resistance

bill tindall

>Unless one sharpens at an angle more acute than is commonly practiced one will never see a deformation failure in a plane iron. Chipping failures are similarly uncommon. The steels used in plane irons typically dull by abrasion. A2 is more abrasion resistant than carbon steel. So it wears slower. It sharpens slower too(an abrasive process), using marginally hard abrasives such as aluminium oxide. If one has settled on old fashioned abrasives then old fashion steel can be a better choice because it hones faster. With harder abrasives, for example diamond, one can take advantage of more abrasion resistant steels that yield longer lasting edges. See Steve Elliot's seminal discouse on these issues.

So, the bottom line is the sharpening system must be considered along with the plane iron steel selection.

Re: It is all about abrasion resistance

ThomD

>You may be right. You identified some interesting issues, but what does it mean to say it is an abrassive process as though that explains everything away. Diamonds "cut" steel, and their ability to resist deformation is critical. They are not only hard, but sharp, and not friable like the chrytals you scorn. This is a similar situation to carbon vs A2.

I don't think it's a wild theory that blade edges fold, it's actually something one can see with one's own eyes, the brass bar test.

Normally the edge on a scraper plane lasts less well than on a regular plane. It's not immediately obvious to me the change in bedding angle is increasing the edge's exposure to abrasion.

I think what we get with a lot of this stuff, including anything I have to say, are just interesting story lines that seem to fit all the comon situations we normally encounter. Since I'm into tools, knives, razors, and blacksmithing, I have the trial of trying to integrate as many of these far fetched tales as possible. I'd sure love to see anything that is more rigorous, including what Steve may have written.

Re: Question about replacement plane irons?

ThomD

>Absolutely! Feedback is very important. The feeling that something is actually happening on a fine stone, that you have some traction and can sense when everything is lined up and cutting. it's a bit like golf where people say that prefer the feel of a particular putter or ball, but in special tests it turns out to be the sound at impact. Who knows what it is exactly, but the human element is important.

for more on this subject......

bill tindall

>Brent Beach and Steve Elliot have investigated plane iron wear including photomicrographs of worn edges. They both have extensive web sites with their results. The inherent wear resistance of the steel strongly correlates with how long the edge lasts with use.

Dulling by deformation and chipping are the main concern in things that are pounded, for example chisels. Search the Badger Pond archives for photomicrographs I posted on these failures in chisels. In these cases the steel requires a balance between toughness (resistance to chipping) and hardness (resistance to bending), while wear resistance is less important. Because hardness and toughness are trade-offs in the steel heat treating process, any comparisons between steels must consider the heat treating for each.

Re: for more on this subject......

ThomD

>Thanks for the heads up. I will check that out.

In sumary therefore. If one applies force to an edge in line with it's CL (where it is just parting the waves like the prow of a ship), it wears by edge deformation, but if one applies force at a consistant 32.5 degrees off the CL (plane) the wear is largely abrasion. Call me Horatio, cause that is unexpected to say the least. That's about as expected as saying that when I grind steel with my belt sander, it's mostly deformation, and when I work it on an anvil it's mostly abrasion. That's the joy of photography the results often aren't what are expected, like that bees row/swim through the air vs. fly.