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Gouge heat treatment

Neil S

Neil S

Joined
Feb 3, 2010
Messages
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Location
Adelaide Hills, Australia
We know from Lyle Jamieson, who has his signature bowl gouges made by Doug Thompson, that Doug heat treats his gouges from end to end....

Something odd.....failure to raise a ground bur on one of my scrapers.

I was turning last night, and something odd happened with one of my scrapers. This scraper is M2 HSS, and has been in use for quite some time with no problems raising a ground bur. This particular scraper failed to raise a ground bur as it usually did. My grinding wheel is Norton 8" SG 80gt...
www.aawforum.org www.aawforum.org

Can anyone confirm that is also the case for D-Way gouges?

I know that the screw hole in the backend of the D-Way gouges is there is to suspend the gouges during heat treatment, but that doesn't answer the question as to whether the full length of the D-Ways are heat treated.

What about some of the other well known gouge brands from the US and UK?
 
It would be variations in the heat treatment, sight unseen its very difficult to know exactly. There would little to no benefit in hardening part of the tool, other than a glitch in the system, as the heat treatment would be automated
 
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The hole in the end of the D Way gouges is so that they are all suspended while getting heat treated. This insures even hardening through out the entire length of the tool. An old practice was 'induction' heat treatment where the fluted parts of the gouge were put in an induction coil and just that part of the gouge was treated. Both Thompson and D Way are done the way I would do it if they were my tools to make.

robo hippy
 
I did some work for the firm that D-Way used for heat treating several years ago - they are extremely well known and respected in the aerospace industry. Massive vacuum ovens and esoteric gases piped in on strenuous schedules are typical of their work. They’re far from only treating the tips…
 
It isn't uncommon to only heat treat the business end of cutting tools. The most common cutting tool that is only heat treated to max hardness on the cutting end are drill bits. If the shanks of drills were hard like the cutting end you wouldn't be able to grip them in a 3 jaw chuck. Another reason for only the end being heat treated is so the complete tool won't be brittle like the hardened end.

If gouge breaking off in a catch was common then only heat treating the cutting end would be a good idea. If the gouges were designed to be held in a handle with set screws then being hard in that area would not be good, set screws don't grip well on hardened surfaces.
 
Thank you for your responses. That is what I expected to be the case.

Prior to milling gouges from bar stock the narrow tapered tangs on forged tools were not hardened like the working end of the tool for several reasons. That end was how the tool was held during heat treatment and therefore remained softer. It also meant that the narrow tang was less brittle and therefore less prone to snapping off there in use.

Solid round bar stock doesn't seem to have the same risk. As far as I know neither of the full length hardened Thompson nor D-way gouges have snapped in use, mis-use aside.

Traditional heat treatment methods used in the UK may have persisted there with adoption of pre-formed round bar stock. Does anyone know about what they do? Obviously the double-ended Crown bowl gouges are fully hardened on both ends, but that might be the exception....

www.oliverswoodturning.co.uk

Crown CRYO Double End Bowl Gouge - Olivers Woodturning Tools

Buy the Crown CRYO Double End Bowl Gouge with a Fingernail Grind at one end and a Standard Grind at the other. Available in three sizes.
www.oliverswoodturning.co.uk www.oliverswoodturning.co.uk

I'm asking this as I'm on a project that is using the other end of gouge bars that are hardened along their full length.
 
Doug from Thompson Lathe Tools has never questioned a tool break even though the tool broke 5 inches from the tip (for me that says way to far over the tool rest), Doug has a great guarantee. One day in his shop I found a 3/4 V gouge in the trash and it looked great to me, I asked why and Doug said it touched the outside of the bin during heat treat and would break. Me being me (having my doubts) asked if I could have it, Doug said it will snap. I got it home and first chance I got I took a cut on a bowl, got about a half inch BANG! When Doug says something about tools I listen. No tool steel can be perfect all the time and breaks do happen but they are rare and far in between, even 5" off the tool rest. The Thompson tools are heat treated totally so the end in the handle is as hard as the cutting end and I hold them in handles that use two grub screws and they hold very very well, never had one come loose.
 
Doug Rasmussen said:
If the gouges were designed to be held in a handle with set screws then being hard in that area would not be good, set screws don't grip well on hardened surfaces.
Click to expand...

This is not an issue. There is little force inline with a gouge, and not much more perpendicular force. A bit of torque can be felt in the handle with a long wing gouge having a wing buried, but I’ve never had one torqued enough to slip in my hand. The lever arm (tool center to cutting edge) is pretty small. All of my removable tool handles use 2 set screws, and have never slipped.

A different application, a hollowing tool with an extended from center cutting edge, is a different animal, but those typically have a mild steel bar with a screw on tip. The mild steel can have a flat easily filed to prevent rotation, but for hand held use a swan neck where the cutting edge is on center - no torque.
 
JeffSmith said:
I did some work for the firm that D-Way used for heat treating several years ago - they are extremely well known and respected in the aerospace industry. Massive vacuum ovens and esoteric gases piped in on strenuous schedules are typical of their work. They’re far from only treating the tips…
Click to expand...

Jeff, do you know if their treatment processes included tempering down to cryo temperatures?
 
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Neil S said:
Jeff, do you know if their treatment processes included tempering down to cryo temperatures?
Click to expand...
They had that capability, the Company specializes in exotic metals mostly for the aerospace industry where there is little room for anything less than perfect. It has been a while since I’ve been there, I retired from my industrial marketing firm back in 2015, but they are - and were - one of the premier exotic metal fabrication and heat treating plants in the area (Western Washington has a number of firms that offer similar services - Boeing is one of our local manufacturers, along with several other aerospace manufacturers like Space X).
 
JeffSmith said:
They had that capability, the Company specializes in exotic metals mostly for the aerospace industry where there is little room for anything less than perfect. It has been a while since I’ve been there, I retired from my industrial marketing firm back in 2015, but they are - and were - one of the premier exotic metal fabrication and heat treating plants in the area (Western Washington has a number of firms that offer similar services - Boeing is one of our local manufacturers, along with several other aerospace manufacturers like Space X).
Click to expand...

OK, Thanks, Jeff.
 
I expect the place Jeff is mentioning is Pacific Metallurgical. That's the place I used for all our heat treating. Also used their sister company that does metal testing to identify unknow metals when we were reverse engineering of unavailable parts. I never had a need to use heir cryo services.

Anyway, I learned something new today. While I've heard the term "grub screw" I wasn't sure exactly what it meant. A bit of Googling tells me it's like a set screw. But a big difference, a set screw can have a head like the square heads on the set screws used to fasten cutting tools on a lathe tool post. A grub screw does not have a head. I have never seen grub screws mentioned on technical drawings so the usage may be out of favor in the engineering field.
 
Doug Rasmussen said:
Anyway, I learned something new today. While I've heard the term "grub screw" I wasn't sure exactly what it meant. A bit of Googling tells me it's like a set screw. But a big difference, a set screw can have a head like the square heads on the set screws used to fasten cutting tools on a lathe tool post. A grub screw does not have a head. I have never seen grub screws mentioned on technical drawings so the usage may be out of favor in the engineering field.
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The only difference between a "grub screw" and a set screw as used by woodturners is a couple thousand miles of ocean. The British grub screw is exactly the same thing as the American set screw. For some unknown reason, when Americans take up woodturning they start speaking British English. :D

For "normal" Americans, a "grub screw" is a set screw that has a head of one type or another.
 
As @Bill Boehme says its an across the pond thing, not sure if England or Aussie/Kiwi land though. In a 40 yr US engineering career nobody called them “grub screws”. I saw the term when I started turning
 
Doug Freeman said:
As @Bill Boehme says its an across the pond thing, not sure if England or Aussie/Kiwi land though. In a 40 yr US engineering career nobody called them “grub screws”. I saw the term when I started turning
Click to expand...

We also call the ones without the drive nut a grub screws down our way. Not surprising that those of us that work with wood call a screw that is buried down a hole a grub... they even look like some grubs (borers) we find in wood... :~}
 
Wrench = spanner
car references
trunk = boot
hood =bonnet
bezel = escutcheon
smack it with a big hammer = rap smartly with mallet
 
Traditional heat treatment methods used in the UK may have persisted there with adoption of pre-formed round bar stock. Does anyone know about what they do? Obviously the double-ended Crown bowl gouges are fully hardened on both ends, but that might be the exception.

I live in the Uk and a number of years ago I spoke to Crown tools They said they do not heat treat the entire length of a traditional tool The rational is if you have a catastrophic event then the tool fails and this is regarded a safer design
It is my understanding but I cannot be certain All the woodturnig Uk companies use a company in Sheffield to heat treat tools

Heat Treatment Specialists of Steel Services | Summitglow Ltd

Summitglow Ltd provide the heat treatment of steel plus case hardening and nitriding services in the UK. Call 0114 270 1866 for further details.
www.summitglow.co.uk
 
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Brian Deakin said:
Traditional heat treatment methods used in the UK may have persisted there with adoption of pre-formed round bar stock. Does anyone know about what they do? Obviously the double-ended Crown bowl gouges are fully hardened on both ends, but that might be the exception.

I live in the Uk and a number of years ago I spoke to Crown tools They said they do not heat treat the entire length of a traditional tool The rational is if you have a catastrophic event then the tool fails and this is regarded a safer design
It is my understanding but I cannot be certain All the woodturnig Uk companies use a company in Sheffield to heat treat tools

Heat Treatment Specialists of Steel Services | Summitglow Ltd

Summitglow Ltd provide the heat treatment of steel plus case hardening and nitriding services in the UK. Call 0114 270 1866 for further details.
www.summitglow.co.uk
Click to expand...

Thanks for that helpful information Brian.

All of my UK made woodturning tools are many decades old and I expect were heat treated in the traditional way with softer steel being left on the tang end. As you say, this is beneficial where the tangs have a small cross-section like they do with traditional style roughing gouges and scrapers... where it is better for the tang to bend than snap off...

bent spindle roughing gouge.jpg
​
However, I expect with some of the newer 'heat' treatments, like sub-zero (cryo) tempering where the whole tool is treated inside a controlled environment container, that this could have changed. The fact that Crown state about their Cryo treated roughing gouges "are tested at the tang to ensure that they absorb the shock generated by roughing out without danger of snapping before leaving the factory" may indicate this.
 
Neil S said:
Thanks for that helpful information Brian.

All of my UK made woodturning tools are many decades old and I expect were heat treated in the traditional way with softer steel being left on the tang end. As you say, this is beneficial where the tangs have a small cross-section like they do with traditional style roughing gouges and scrapers... where it is better for the tang to bend than snap off...

However, I expect with some of the newer 'heat' treatments, like sub-zero (cryo) tempering where the whole tool is treated inside a controlled environment container, that this could have changed. The fact that Crown state about their Cryo treated roughing gouges "are tested at the tang to ensure that they absorb the shock generated by roughing out without danger of snapping before leaving the factory" may indicate this.
Click to expand...
Most if not all of the heat treating processes would be automated today, but it wouldnt surprise if there were a few using traditional methods. I have an idea that much of what this company does is still by hand. But at the end of the day its process over cost plus quality equals staying in business, innovation would be darn near a necessity today.
 
Neil S said:
Thanks for that helpful information Brian.

All of my UK made woodturning tools are many decades old and I expect were heat treated in the traditional way with softer steel being left on the tang end. As you say, this is beneficial where the tangs have a small cross-section like they do with traditional style roughing gouges and scrapers... where it is better for the tang to bend than snap off...

However, I expect with some of the newer 'heat' treatments, like sub-zero (cryo) tempering where the whole tool is treated inside a controlled environment container, that this could have changed. The fact that Crown state about their Cryo treated roughing gouges "are tested at the tang to ensure that they absorb the shock generated by roughing out without danger of snapping before leaving the factory" may indicate this.
Click to expand...
It is difficult to tell from your picture but if the tool is a Spindle roughing gouge then these tools can bend if used for tasks other than spindle roughing
I think it was Stuart Batty who stated that Craft Tools were having about 100 roughing gouges returned each year because they had failed
The company to reduce this issue renamed the tool Spindle roughing gouge
 
Following your collective advice, I was encouraged to go ahead and grind a flute into the tang ends of a Thompson and D-way bowl gouge. I can confirm after doing some test runs that the steel in the tang ends of those two gouges were fully heat treated and the steel in that tang end performed every bit as well as the primary flute end. I report on that project in the thread, DIY bowl gouges and flutes
 
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