Trouble With A LVLA Smooth Plane

Re: confirmed by supplier

fkrow

>With all due respect to Crucible, their published directions for heat treatment are a geneal starting point. Most users will modify and tweek the time temperature relationships to change physical properties. This is the "black art" part of metallurgy.

The measurable & observable effects of deep cryo have been studied.

http://www.onecryo.com/onecryo/cryogenic-tempering.htm

Is it worth the additional cost to the manufacturer and consumer? Only the market will tell us in the long term.

Regards,

Fred Krow

Re: Cryo...

Patrick Gibbons, Houston, TX

>I remember once having to wait outside of Chicago's O'Hare Airport for a bus to pick me up and take me to a hotel. It was about -300 degrees and boy did I get cryoed out there. It did give me a much stronger temper but did nothing for my edge-holding abilities. Heck, I couldn't even hold my suitcase. I like the LV replacement blades. They perform wonderfully. Don't know how they could be improved by any process.

Re: Cryo...

steve knight

>all I heard that cryo does on A2 is reduce the size of carbon bits so the blades will sharpen to a bit finer edge and not be so brittle. nothign about a longer edge holding.

Liquid Nitrogen

Derek

>is 77 degrees Kelvin, which is approximately -320 degrees F. What do they do to keep it at 100 degrees? It must be either under tremendous pressure or in acetone which is cooled by the nitrogen, but not immersed in it.

I worked with the stuff for years as well as liquid helium (4 degrees Kelvin...).

Re: Cryo...

fkrow

>Steve,

Yes, the most observable improvement with deep cryo (-330F) is the finer carbide size.

Wear improvement will be dependent upon the user, sharpening angles, type of wood (exotics or native hardwoods), thin cuts with slow gentle planning vs. thicker cuts with agressive fast planning. This is reported with the cryo treated metal cutting tooling from various plants, some show great improvment in life others see no change.

I have two of your smoother planes (45 & 50 degree) with the Starrett O-1 steel blades and they are excellent. I believe you have more than the retained austenite transformation to martensite going on with the cryo treatment.

Regards,

Fred Krow

Re: Double Tempering

fkrow

>Here is another example of "black art" vs. steel mill recommendations for heat treatment.

Double tempering - The folks at Warren Cutlery make wood carving knives and gouges. I had an interesting discussion with the owner last year. He stated that the change to their 1095 steel heat treatment to add double tempering greatly increased the time between sharpenings, their customers were very happy with the improvements. The traditional heat treatment of 1095 is single temper.

Triple tempering - One of the suppliers of D2 steel rolls for our rolling mills used a triple temper schedule and had very improved life. Again, out of the text book and steel makers standard recommended heat treat directions.

Regards,

Fred Krow

Re: Liquid Nitrogen

Mike Lietzow

>What we used to do when we wanted temps slightly greater than liquid N2: Immerse a coil in liquid N2. Run N2 gas through the coil and heat cooled gas to the desired temperature.

Cheers,

Mike

btw: you can get below 4 Kelvin by promoting boil-off of liquid helium. This is common practice in many supeconductor magnets.

So any idea of how much it costs

Jim in Burlington Ontario

>Anyone guess at how much per blade the cost is? I was just thinking if Hock thought it was worth to sell more blades it couldn't cost that much per iron.

Re: So any idea of how much it costs

fkrow

>Jim,

About 5 years ago, I was interested in precision bench rest rifle shooting. I used 300 Below, Inc. in Decatur, IL. The cost if I remember correctly was approx. $30 for a rifle barrel with action assembly. I had three rifles treated however, I did not keep detailed records of life. My interest in shooting passed before I could wear out the barrels.

The units used by 300 Below, Inc. have a capacity of 2,000 lbs per cycle.

http://www.300below.com/site/home.html

I have not done any machining tooling or wood working steel cryo expermentation.

My planes have blades by Hock, LN, LV and Steve Knight. All are excellent, I enjoy working with the wood too much to take the time for wear comparison testing. At this time, sharpening is more interesting than heat treatment and metallurgy.

Interesting discussion on a controversial topic.

Regards,

Fred Krow

Boy, you'd never make it in Minnesota, Patrick

Bill Houghton, Sebastopol, CA

>Minnesotans don't even put on a sweater until it gets below -300.

Re: Boy, you'd never make it in Minnesota, Patrick

Patrick Gibbons, mcgdogm, TX

>Minnesota? Heck, I couldn't make it in Amarillo.

Re: So any idea of how much it costs

Cameron Miller

>Fred said:

"I have not done any machining tooling or wood working steel cryo expermentation."

and:

"I enjoy working with the wood too much to take the time for wear comparison testing."

So you've not done much in the way of controlled testing and comparison, yet basically dismiss Rob's comments when he's done extensive testing?

Have I got that right or am I misinterpreting something? Not really trying to stir the pot but I'm just trying to understand where you're coming from, that's all.

Re: So any idea of how much it costs

Frank D. in Montreal

>Hi Cameron, I'm not Fred but if you read one of his posts above (in response to Mr. Lee) you'd find this:

"Mr. Lee,

Interesting comments, thank you.

I made a business visit today to one of the major USA bearing manufacturers, the dept. head of their testing lab is an old classmate. We were discussing bearing life in the rolling mills my company designs. He commented that with one of the commonly used bearings in my machines that his competition has always produced bearings with longer life. He purchased some of their bearings and checked the metallurgy and heat treatment,,,,exactly the same material and hardness, etc.

The only explanation their metallurgists could present was the actual process of making the steel used by the competition was different than their source of steel.

I have also observed this difference in wear with D2 steel rolls for our mills. Some steel makers have superior steel for life and toughness. The chemistry is textbook identical however, the end product is much improved.

Obviously you have tested your source of A2 steel with and without -300F cryo. Have you tested other producers of A2?

We also have had problems with commodity (low price wins the bid) tool steels having poor quality compared to those steels with mill certifications and identified sources."

I think it's quite clear where Fred is coming from. And he was forthright enough to mention that his experience did not extend to woodworking tools. That doesn't, as you seem to imply although I'm not sure, invalidate his input on the cryogenic process, and I don't think he dismissed anything said by Mr. Lee. In fact I appreciate the fact that that someone who has some first-hand knowledge about the cryo process takes the time to talk about it to us here on the forum. Do we really have to pick at him about his credentials?

Frank

Re: So any idea of how much it costs

Rob Lee

>Hi Cameron -

Just wanted to say I don't take issue with any of the comments here... it's a good discussion.

While we are doing testing, our investigation is very limited in scope...A2, and for hand tool(plane) usage only. We're not looking at all steels, nor all processes.

There's a lot of information out there, but a lot of it is anecdotal, or inapplicable to the application we're looking at.

Lots of room for opinion and discussion either way!

Cheers -

Rob

Re: So any idea of how much it costs

fkrow

>Rob,

Thank you for your comments, I did not prolong the cryo discussions to be critical to Lee Valley products. If the improvement to A2 from deep cryo wrt wear resistance is not observable or very small, it is just not cost effective.

Many companies advertize the cryo advantages however, yours is the only one to my knowledge that is actively testing the A2 steel in woodworking applications. There are several hundred companies offering deep cryo treatments of metal but very little actual data to support the claims.

Regards,

Fred Krow

Re: So any idea of how much it costs

Cameron Miller

>Mmmm, I thought we were talking about woodworking tools here, specifically planes and plane blades? Bearings and rollers are an entirely different matter and I must admit that I wasn't exactly taking them into account at all. After all the ability for a bearing to hold an edge isn't really applicable here.

I should also add that I wasn't attacking Fred at all, just trying to understand the basis of the "arguement" and why he might be of a differing opinion to Rob (in particular). I was hoping that Fred might expand a bit more as to why (in my opinion) he appears to invalidate Rob's findings on the matter when it comes to cryo treating of edge tools. Not saying that he's right, wrong or indifferent - just trying to find out a bit more about it.

I have my own opinions on the matter, but it's always good to hear what others have to say about things.

Re: So any idea of how much it costs

fkrow

>Cameron,

I was curious on Rob's testing in that he found no advantage to deep cryo. Many field tests of metals in many varied applications have recorded very significant advantages wrt wear properties after deep cyro. My own personal experience is with deep cryo to precision target rifle barrels and with the bearing/rolling mill industry were the -100F cryo is commonly applied.

I worked in the bearing industry years ago as a product designer and presently work in the steel mill industry and therefore I am very interested in testing results. My questions were originally intended to establish the testing parameters by Lee Valley. Rob and his people have done a very thorough examination of A2 steel for wood working applications. They have examined the variables and are continuing the testing, that is admirable and shows their commitment to a fine product.

In the bearing and rolling mill industry, if we consider fatigue as a component of wear properties, then the metallurgy of deep cryo is applicable. I have also been involved with custom steels and heat treatment for knife making for over 30 years, edge holding properties are very important to the knife industry. We find that edge geometry is one of the most important variables in knife testing. One of the most respected custom makers uses D2 steel and also does not belive deep cryo has any effect on wear. Others claim they observe increased edge life with the treatment.

I have also read the claims published by the providers of deep cryo heat treatment, it cannot all be eyewash......several hundred firms arround the world have successful businesses with deep cryo as their main income.

Regards,

Fred Krow

Re: So any idea of how much it costs

Cameron Miller

>Thanks Fred. Much appreciated for the expansion/explaination. Hope I didn't offend at all?

Re: So any idea of how much it costs

fkrow

>Cameron,

Not at all, thanks for joining the discussion.

Regards,

Fred Krow