Another Toolmaker/Blacksmith Question

another reason why forged is stronger

Peter Berglund in Denver

>I may be full of it on this, but I relate the difference between forged and cast steel (the original billet) to the difference between igneous and metamorphic rocks. (hey, I'm a geologist, gimme a break). Igneous rocks have interlocking, randomly oriented crystals. They break along crystal boundaries. Metamorphic rocks, having been modified under heat and intense pressure, tend to have parallel crystals, aligned according to the stress field under which they were formed. It's simply a stronger structure, more resistant to breakage.

rocks in my head,

Peter

Re: Another Toolmaker/Blacksmith Question

joel

>THe bessemer process only produces mild steel with is NOT a tool steel.

You are thinking of Crusicble steel or "cast steel" invented by Benjamin Huntsman in 1740.

Blister steel and shear steel were also quite popular and we made I think until the 1930's (or a little earlier)

Steel recipe madness

Jim Reed @ Tallahassee

>Good start, but maybe too generalized for my taste. I think steel recipes should be thought of like food--pizza everywhere all share similar characteristics, but are quite different. For example, I buy flat stock from MSC. Their specs for 01 and A2 are pretty similar except for amount of chromium (A2 has about 10 times more than O1). Both contain about the same amount of vanadium. Chromium and vanadium do not make bad steel as your article implies. I think heat processing determines performance almost as much as steel stock selection. In my experience, poor quality tools almost always have poor and inconsistent heat treatment (ie chisels of same type from mfg have different hardnesses). Softness and inconsistency are my biggest gripes.

Martensite and pizza *LINK*

Jonathan Peck - N.Y.

>Try doing a google search on martensite present in steel microstructure for a scientific approach to steel hardness and heat treatment.

Vanadium is added for resistance to annealing

Chromium is added for corrosion resistance

Higher Carbon content makes steel harder and more brittle

Tempering reduces brittleness and makes steel less hard.

Somewhere holds a balance.


Selection of tool steels

BTW

Jonathan Peck - N.Y.

>Inconsistencies in temper are more likely traceable to some slowhead and his new 'lectric grinder than to the factory from which they came. This ofcourse would be imposible to prove but more than likely the case

Re: Another Toolmaker/Blacksmith Question *LINK*

Jonathan Peck - N.Y.

>This is one of my favorite stories


Benjamin Huntsman

Not my experience

Jim Reed @ Tallahassee

>If an edge has touched a grinder, it was probably toasted. I have seen some real messes. Oddly though, most of the bench plane blades I have seen (and there have been hundreds) have never been sharpened.

skeptical....Me?

Jonathan Peck - N.Y.

>"most of the bench plane blades I have seen (and there have been hundreds) have never been sharpened."

In short...heh? Not that I'm the least bit skeptical, but you must live in a real tool heaven where Stanley's in Excellent condition are found under every rock and hang from the trees:-) So...how do you get hunderds of guys with vintage Stanley planes that have never before been used to let you take their collectables down to the woodshop to sharpen their never before been sharpened original factory grind irons and take them for a test drive??????

Regards

Jonathan

Thanks All - Here's the Second Draft

Bob Smalser, Seabeck, WA

>What you need to know about chisel steel.

Here are the steels commonly found in today�s chisels.

High Carbon Steel

After the processes were developed and refined during the middle 1800�s to reliably produce large quantities of high carbon tool steel inexpensively, such steel became the mainstay of edge tool production that continues today. �Warranted Cast Steel�, �Sheffield Steel�, modern 01 and other Tool Steels, �Swedish Steel�, and others. (It was the Swedish iron ore, not necessarily their steel that was better, as it lacked the phosphorous that makes steel brittle.) Many of the chisels made during Bessemer�s lifetime still serve admirably today, as properly forged carbon steel takes an excellent edge while is very easy to resharpen using traditional composite, water or oilstones.

Chrome Vanadium Steel

A modern, shiny tool steel used for mechanic�s tools and commonly seen in lower grades of chisels. The chromium and vanadium add hardness, toughness and rust resistance, and if properly made, can take a good cutting edge. I�m not sure if it�s the steel or the manufacturing process, but they are generally more difficult to sharpen than carbon steel, and in lower tool grades can be impossible to obtain an �excellent� cutting edge.

High Speed Steel

M2 and other formulations. Chromium, tungsten, molybdenum and vanadium are added to resist softening when the steel is overheated during use or sharpening on a high-speed grinder. Used primarily in high speed drill bits and in lathe tools, this steel is hard, tough, easy and fast to grind, holds its cutting edge longer than carbon steel, but is very difficult to hand hone and doesn�t take as fine an edge.

A2 Steel

The modern compromise. High carbon steel with chromium and molybdenum added in smaller amounts than some other modern steels, but sufficient to add some toughness, hardness and longer edge life at minimum expense to the quality of the cutting edge and ease of sharpening. I find these blades only slightly more difficult to hand hone on traditional oil stones than carbon steel, and it is doable without resorting to the modern diamond pastes often recommended. I also find A2 blades take a very good edge and hold it as long or slightly longer than my best prewar carbon tools.

Rockwell Hardness

More compromises. The Rockwell index is simply a hardness test of the final, tempered blade. Chisels available today can range from RC 56 (relatively soft) to RC 64 (relatively hard). Softer steel is easier to sharpen but doesn�t hold its edge as long as harder steel, which takes longer to sharpen but holds its edge longer. Chisels above the RC 62 range can also be brittle, if not during use then when you accidentally knock one on a concrete floor and find you have a badly chipped edge that must be severely reground, shortening the life of that tool. As a practical matter working at or close to a bench, I find chisels so fast and easy to touch up on the stones, that harder isn�t better for me - my preference is the sharpest cutting edge I can hone, but hone easily. In my plane irons however, it is real convenient to not have to dismantle, hone, reassemble and adjust any more often than I absolutely have to, and depending on the plane, that preference may be secondary to my very best cutting edge.

Forging � does it make a difference?

I think so, but it can be controversial. One view is that the more the hammer is used in shaping the blade as opposed to grinding, the smaller the crystalline structure and the better aligned it is with the cutting edge, with other benefits in carbon and grain size as well. Older tools and hand-forged tools are better because they have been shaped more by forging than modern tools. The counterargument is that modern steels benefit most from proper heat treatment, and that poor results come from manufacturer shortcuts taken to cut costs, not lack of forging. The middle ground is that forging is more expensive, and a manufacturer going to that expense is more likely to get the rest of it right.

As a practical matter in chisels, the differences are often subtle and subjective, but are certainly there. Almost all my older professional friends in the woodworking trades much prefer the best prewar makes of chisels to new factory chisels, however expensive. Hand forged, best-quality steel is the mainstay of legions of knowledgeable Japanese tool woodworkers, and toolmaker Barr Quarton wouldn�t still be in business after over 20 years of hand-forging edge tools if he didn�t have a superior product.

Re: Thanks All - Here's the Second Draft

Chad Boehlke

>I hand-forge woodworking tools for my self and others. I agree with your statement about forge blades. I find forge blades to be stronger, better sound, better sharpness, and pride in ones work. I heat treat my irons with the forge and a magnet. Chad

I agree

Todd Hughes

>While I certainly see some plane blades that haven't been sharpened much,[and some of them maybe never] I think most i have seen have been sharpened with a good many sharpened ALOT. I have seen a good many planes that don't show signs of being used alot really but whose blades have been sharpend up a good bit. Probably from guys go crazy on a grinder and not knowing how to sharpen...well my take on it....Todd

Re: Thanks All - Here's the Second Draft

Todd Hughes

>I think the reason that older chisels maybe are better then most modern ones isn't because they were forged more, I think your Witherby wasn't really forged much more if any then your modern chisel which doesn't perform as well, but is because they were tempered better. Also most modern chisels are softer because they are a compromise, modern makers are probably more worried that thier chisels won't stand up to opening paint cans then that they will stand up to fine cabinet work....Todd

sharpening tools steels

bill tindall

>Bob Elliot has done some careful experiments on sharpening tools steels. Check his web site for the facinating results of some well executed experiments. Bottom line: of the steels he has evaluated, they all can be sharpened to the same degree, but the highly abrasion resistant steels can not be sharpened as easily to this high degree. This fact has led some to falsely conclude that they can't be sharpened to the same high degree.

Thanks

Bob Smalser, Seabeck, WA

>Terrific. Thanks. Noted.

Took 1 micron diamond paste, though, for the alloys to equal A2 and Carbon, although once sharp their edge retention was better:

quote

After starting the edge retention tests I found that some blades would reach a level of sharpness I could not duplicate on other blades. The types of steel that achieved the sharper edges were plain high carbon and A2. The alloy blades such as CPM 3V and Holtey�s S53 would not take as sharp an edge, although their sharpness was still very good. The differences in initial sharpness can be seen clearly on the first edge retention chart for planing cherry.

The poor performance of the Holtey S53 blade when honed with a Norton 8000x waterstone surprised me because the blade had performed better in earlier tests when it had been honed with 1 micron diamond paste on a cast iron lapping plate. When I rehoned the S53 using diamond, its sharpness was similar to the sharpest edges I had produced on other steels. The CPM 3V also attained a significantly sharper edge when honed with diamond. I haven�t yet tested the edges produced on other steels when honed with diamond.

At this time I haven�t answered the question of whether some steels will take a sharper edge, but the level of sharpness I�ve attained on each of the blades is so good that I believe the question has little practical significance.

unquote

Re: Thanks All - Here's the Second Draft

Jesper, Denmark

>Just a comment on the last para, mentioning Japanese chisels.

They are usually laminated, forging a high carbon steel to a softer back. This gives the high Rockwell hardness in the edge with a less brittle back.

Jesper

Re: sharpening tools steels

paul womack

>Bob Elliot has done some careful experiments on sharpening tools steels. Check his web site

Can't find it - any clues (like a URL :-)

BugBear

Afraid to say

Jim Reed @ Tallahassee

>Ebay, of all places. Rust hunting was poor in the Atlanta area (and I do not think FLA is any better). In my collecting prime, it was rare to get an Ebay plane with the blade touched. Sometimes they were scratched on a stone to touch up, but almost never ground. Most (50--60%) were just peachy new under the rust. I think many carpenters lacked the time necessary to develop good sharpening skills.

Site URL *LINK*

Steve Elliott

>Here's the link. I'm still doing the testing, so the site is just a rough draft at this point.


Comparison Tests of Plane Blades

Basically,

Peter Berglund in Denver

>It's all a tradeoff between hardness and toughness. The harder the steel, the more difficult to sharpen a razor edge, but the longest edge retention. And the harder, the less tough; I wouldn't want to pound dovetail waste with a Japanese chisel. Steel that's tempered to a slight degree softer will sharpen to the very sharpest edge, but you'll be honing more frequently.

I've got the Robert Sorby octangonal handled bench chisels, and their paring chisels as well; seems to me the paring chisels are softer...

Peter

Re: Basically,

Pam Niedermayer - Austin, TX

>I wouldn't want to pound dovetail waste with a Japanese chisel.

Why not? Jim Kingshott loved Japanese chisels for that job. I do, too.

Pam

Re: Basically,

Peter Berglund in Denver

>Didn't mean to malign Japanese chisels; just assumed that an edge that much sharper would also be more brittle.

P

Re: Basically,

Pam Niedermayer - Austin, TX

>As you work Japanese chisels they seem to get tougher. Also, technique is important; so, at least at first with a new chisel, you probably don't want to forcefully lever much with them. But the wickedly sharp edges make dovetail chopping a real pleasure. And paring with Japanese chisels is a bonefide pleasure, right up there with making wispy shavings.

Pam

Particle steels,etc

Bob Hackett

>I noticed you mentioned it here but there was no mention in your article.Particle steels are a very big thing now with woodturners.I don`t know if you are aiming this toward all WWers or just handtool users but it seems folks like Bill are dragging these type of steels into our slice of the world as well.

You mentioned forging as a way to refine the steel.Although some may disagree I think history bears out the fact that a skillfully worked blade will outperform drop forged tools.Most smiths that were paying attention while learning from the old hands still do things like packing an edge to make things like stoneworking tools more durable.

A good explanation of the difference between hardness and toughness and how heat treating plays a part in both is essential.I have yet to hear one that doesn`t leave rank beginners with the "huh?" face.Choosing the right steel for the intended task the tool must perform is the first step.It doesn`t matter how good the steel is if the heat treating goes badly and fails to bring the reasons you chose that steel out.

I also think it`s a good idea to list references.A short,generalized article can go along way with references for follow-up reading,Just my .02 here.

I know it`s tough trying to distill years of information and experience down in this type of article.I can think of nobody who is better qualified to present it in clear,easily understood terms than yourself.I look forward to reading and using the final draft.

Mainely,Bob

not the whole story, hardness, toughness and abras

bill tindall

>The three most important properties we worry about are hardness, toughness and abrasion resistance. They can be controlled and optimized by alloy selection and heat treating. A change in composition or heat treating that affects one of these factors often will affect the others as well, for better or worse.

Rockwell hardness is a measure of resistance to penetration and it most closely correlates to resistance to deformation (bending, crumbling). So the harder the metal the less likely the edge is to bend or crumble in use.

Toughness is a measure of how easily the metal breaks under stress. A tough edge will resist breaking or chipping. So ,for example, M2 can be made very hard but the edge will fail by microchipping because M2 is not particularly tough. 3V is very tough and the likely failure mode for a 3V edge under stress will be bending.

Abrasion resistance is most determined by the amount and nature of the carbides present. Vanadium carbide is one of the most abrasion resistant carbides known so steels with vanadium are typically more abrasion resistant than steels with just iron carbides.