Mark,
There is no forum wide ban on selling things on this website and I think as long as a common sense approach is taken, nobody is going to object to bringing new products to the attention of the members or discussions such as this relating to the pros and cons of different types.
On that subject, I was looking at some specs for different alloys and it was interesting that some of the "exotic" alloys (M42, CPM10V and CPM15V) actually had a lower Rockwell hardness but were stated as being much tougher. Toughness is the resistance to wear so perhaps that is a better indicator of edge durability than actual hardness when comparing different alloys and treatments.
Hi Paul
Thank you for the clarification. Also thank you for your point about Rockwell, and the toughness factor. This in my limited form of knowledge in this field is what I was trying to get across it is not just down to one factor. Toughness is the offset between hardness and tensile strength (or so I think) Even the toughness factor may not give total clarity as to how long the sharpness may be held as it is a balancing act.
You are right about some having lower Rockwell but this is 'mainly' in the Powder Metal world but also in some others. ( this I have clarified this morning).
One thing I can clarify is that Crown purchase from a company that employs a 'Dr/Professor'of metallurgy who Crown have gone through on various occasions to have points about the steels they are using clarified prior to production. This is the sort of level of knowledge I am talking about, by all means through research challenge this but again I am just going to leave it to the experts.
This also comes down to alignment of the molecular structure, how fine/compact this structure is and the resulting hardness and toughness throughout the structure which is achieve with Cryogenic treatment over just case hardening or adding a coating.
There is more than one test for toughness as the below PDF goes into and the results of various metals alters depending upon its metallic make up, add heat treatments and when speaking to Crown, to paraphrase ' there are masses of variables,hundreds'.
This being the reason I was indication, and looking at the depth of knowledge needed to fully understand metallurgy, that I said I listen to the experts who are the people within Crown/tool manufacturers, heat treatment experts and metal suppliers to name a few. The science and figures as I say are proven and this is shown in the tools use.
Again if people when they buy a product from a reputable company are not happy with it and feel it does not do what it says then they can have that rectified. Recently I went to my local electrical suppliers to get some products for my electrician. he gave me a list and I purchased it. I didn't I say to him ' well you say this is what will do the job but how do I know, you say your an expert but show me all your qualifications and course figures to quantify what you have said before I go ahead'.
No the electrician is qualified as are the metallurgists, metal producers, manufacturers and heat treatment specialists. By all means people are free to research google and do there own objective research. For me it is rather in depth and over my head and as I say I leave it to the experts.
PDF on toughness showing various tests
http://www.vamas.org/documents/twa21/vamas_twa21_report_48.pdffurther web site in relation to M42 before Cryo treatment.
http://www.hudsontoolsteel.com/technical-data/steelM4
