Page 1 of 3 123 LastLast
Results 1 to 15 of 31

Thread: Hardened steel gouges

  1. #1
    Join Date
    Jan 2014
    Location
    Colorado Springs, Co.
    Posts
    98

    Hardened steel gouges

    I recently had a 3/8" bowl gouge that was getting a little short and when I still had quite a bit of steel left that I could sharpen with my wolverine jig, the steel got soft and mushy. I took a file to it and found that the bottom 3 3/4" of inches of the had not been hardened. I usually repurpose these gouges and was disappointed. I won't mention the brand name because I have been pleased overall with their products and purchased many items in the past.

    Are all gouges only partially hardened??

  2. #2
    Join Date
    Sep 2015
    Location
    San Diego, Ca
    Posts
    1,647
    I don't think that it is terribly unusual for the handle end of a tool to NOT be hardened. If the whole tool is hardened, that slightly increases the chance that you could snap off the shaft if you got a really severe catch or drop your tool on the floor. A file sometimes breaks in two if dropped.

    If you search Youtube, you will see some videos on how to harden steel. It actually is fairly simple to do. People have been doing it for a couple thousand years. I've hardened high-carbon steel but not hss. Of course, you'll need to remove the steel from the handle to heat it. But making a new handle is a simple and fun project.

    But on the other hand - - you probably got a lot of use out of your 3/8" gouge and it is time to retire or repurpose it.

  3. #3
    Heat treating HSS is a complicated process and I suspect beyond the capability of most of us. I have a good friend that manages a heat treat business and the processes he describes are precise and require sophisticated equipment.

    Left click my name for homepage link.

  4. #4
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by Gary Baler View Post
    ...
    Are all gouges only partially hardened??
    Gary,

    Some gouges and tools are hardened for the entire length. I have a box of used tools in handles I save for give away, loan, and for sharpening teaching/practice. On occasion I regrind one for special use. I tested some of them with the file method. (try to scratch the tool with a small triangular file at various places - if the file won't cut but just skids the tool is hardened at that point.) I didn't make a list or even take time to mark them but I found a big variety in the hardness. Some were only hardened on the end. A couple were not hardened at all! Some were hardened up to about the full length of the flute. Some were completely hardened, at least the part not inside the handle.

    I think at least some of the better tools are hardened for the complete length. I think Thompson tools are, at least those I've checked. I think I remember him telling me the entire tool goes through the hardening/tempering process. I have on occasion ground the back end of the shaft into a special tool. I also buy round rods from him and sharpen both ends of the ones I use with handles - I made a couple like this just this week.

    I do know that at least some HSS drill bits are not hardened on back end. I had an drill press "incident" where a steel piece being drilled broke out of the vise - the quality 3/8" bit ended up with a 45-deg bend in the shank. (Always wear safety gear and don't hold a part in your hands!) If the entire length had been hardened I sure the bit would have been broken rather than bent. I don't think this is an issue with lathe tools.

    I'm no metallurgist but from my limited reading hardening HSS is an involved process that may take special equipment, and some types of HSS are apparently more involved than others. Rehardening is apparently even trickier. I suspect it would be better to just throw the tool away and buy a new tool.

    JKJ

  5. #5
    A lot of the low cost M2 tools are induction hardened for about two inches or so.The exotic powdered metal steel tools are heat treated for the whole length because there's no way to avoid it due to the extended time and high temperatures involved.
    Bill

  6. #6
    Join Date
    Jan 2014
    Location
    Colorado Springs, Co.
    Posts
    98
    Thanks for the input everyone. Guess I'm a bit of a cheap-skate but with 3" + of flute left I was counting on a little more use. The mfg. replaced it, apologized, but said that is the way the make them. I have worn out several of their gouges over the last few years that didn't seem to have this issue.

  7. #7
    Join Date
    Nov 2006
    Location
    Erie, PA
    Posts
    564
    Thompson tools are heat treated totally and I assume D-Way are also. I have seen the results of the hardness of several overseas companies gouges and the hardness gets less and less as you go up the shaft towards the hilt and I assume that the reason is the induction hardening.

  8. #8
    The D Way have a hole in the base of them because they hang rather than stack or lay flat. There are some mistakes some times and a tool may not get hardened properly, depending on the manufacturing process. Some have fewer mistakes than others....

    From when I was a pizza cook, 'we don't make mistakes, we eat them...' Kind of hard to do that with metal though...

    robo hippy

  9. #9
    Join Date
    Nov 2007
    Location
    Fort Pierce, Florida
    Posts
    3,498
    A file will break if dropped because it is hardened, but generally not tempered. Tempering takes away some hardness and a file needs all the hardness it can get. My father used to make carving tools from old files, but part of the process was tempering the steel by baking it in the oven. I believe because of the manufacturing method, "crucible steels" like Dougs high vanadium steel and Dave's Cobalt steel require complete heating to finish the sintering process. Also the cryo tempering requires the entire piece be treated. While carbon steel hardens in the 8-900F range, which can be reached with a mapp gas torch, HSS (M2) requires 1450-1500F and is often quenched in molten salt.
    Retired - when every day is Saturday (unless it's Sunday).

  10. #10
    Join Date
    Mar 2007
    Location
    Wetter Washington
    Posts
    888
    The cheap "M2" tools are often heat treated using an induction coil. The tool is held at the fair end and the tip is stuck in the coil. This is why almost all the M2's are not hard all the way up. The better ones are hard for the entire flute. But the cheap ones are often only treated at the tip.
    The file test is a good way to tell, if it skips, the tool is hard there, if the file bites, it's not.
    Making sawdust mostly, sometimes I get something else, but that is more by accident then design.

  11. #11
    Join Date
    Mar 2007
    Location
    Wetter Washington
    Posts
    888
    Quote Originally Posted by Thom Sturgill View Post
    A file will break if dropped because it is hardened, but generally not tempered. Tempering takes away some hardness and a file needs all the hardness it can get. My father used to make carving tools from old files, but part of the process was tempering the steel by baking it in the oven. I believe because of the manufacturing method, "crucible steels" like Dougs high vanadium steel and Dave's Cobalt steel require complete heating to finish the sintering process. Also the cryo tempering requires the entire piece be treated. While carbon steel hardens in the 8-900F range, which can be reached with a mapp gas torch, HSS (M2) requires 1450-1500F and is often quenched in molten salt.

    Ya, but find MAPP today, MAP yes (which doesn't get as hot as true MAPP).
    I have two bottles of true MAPP labeled DO NOT USE, to remind me I can't replace them when they are empty.
    Making sawdust mostly, sometimes I get something else, but that is more by accident then design.

  12. #12
    Finding an indispensable but unusable tool can be like finding a lemon or, as I prefer, a glass of lemonade... A reason to buy a new, better quality tool (e.g., Doug or Dave) should never be squandered!!! Just sayin'

    Ely

  13. #13
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    12,298
    Quote Originally Posted by ELY WALTON View Post
    A reason to buy a new, better quality tool (e.g., Doug or Dave) should never be squandered!!! Just sayin'
    Ely
    Yikes and zounds! I'm supposed to have a REASON to buy a new tool? Why didn't somebody tell me??

  14. #14
    Quote Originally Posted by Ralph Lindberg View Post
    ?... I have two bottles of true MAPP labeled DO NOT USE, to remind me I can't replace them when they are empty.
    The guy who buys them at your estate sale will use them to light his charcoal briquettes.
    Bill

  15. #15
    Join Date
    Sep 2015
    Location
    San Diego, Ca
    Posts
    1,647
    I don't disagree with the comments that hardening and annealing steel is involved and may need to be very exacting to get consistently excellent results. Most people probably should not try it. Leave it to the professionals.

    But I am a tinkerer. I have an electric kiln/heat-treat oven. I also have a PID temperature controller. I also have access to my wife's electric oven (when she isn't home) for annealing.

    I have made several tools from an old high-carbon steel file. Mostly inserts, but also a couple of NR scrapers.

    First, I put the file into a soft state so that I can cut, drill and shape it. I do this by heating in my kiln and letting it cool in there (power off) over night (that is, slowly). After shaping it, I reheat it (typically to the Curie temperature) and quench it in warm oil. Then I do the file test on it followed by polishing it up. At this point it is hard (probably brittle). Then I usually go through an annealing process and watch the surface change color to a light straw. I end up with a sharp tool that is hard.

    But I'm not kidding myself that the process I use is anywhere near as good as real metallurgists follow.

    When I wear my tools down to a point where they are too short to use and where they aren't hardened, I am unlikely to just try to re-harden them. I'll replace them but keep the old tool as a "donor" for some future project.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •