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FREQUENTLY ASKED QUESTIONS
If you have a question not covered below, send a email or call and let me know.
What is powder metallurgy, CPM 10V (A-11) and why is it better than High Speed Steels?
Powder metallurgy is a process where each element to make the steel is processed into a fine powder then mixed and pressed together then heated to produce a high grade alloy steel that could not be made in a conventional manor. CPM 10V (A-11) was made for the industral world, it is used for high wear applications in dies or centerless grinders for example. They have found the hardest and therefore the most abrasion resistant carbides typically found in tool steels are the vanadium carbides, this steel has 9.75% vanadium. M2 for example has less than 2% vanadium. Why is it better than HHS? In short, the process to make the steel and the vanadium content. Therefore the cost to produce this steel is 2-3 times higher than HHS.
Do you need special grinding wheels to sharpen this steel?
No! Any grinding wheel that you use now will work.
As a new turner can I start with quality tools or do I buy a cheap set of tools?
Yes you can start with quality tools if you follow these steps. First buy a Oneway Wolverine jig and Vari-grind attachment, go to Woodcraft and buy a 8" slow speed grinder, they are on sale all the time. This is a one time buy that will eliminate all problems sharpening your tools. Next download the sharpening guide, read it! Now place the tool in the Vari-grind with the grinder OFF place the tool against the wheel and pratice the side to side sweeping motion needed to grind the cutting edge. To learn how to grind using these tools will waste about 1/4 inch of steel, the secret is a very light touch and that is learned. Cost is about 5 bucks. If you need help contact me by email or phone.
The cost to learn with a good tool.
One good tool is worth more than a bunch of cheaper tools. Most professionals only use a couple of tools all the time, tools that they have learned to use well. When starting out ONE 1/2 inch bowl gouge is enough to turn a 12 inch bowl then you add another when you see a need.
The cost to learn on a good tool is low when you break it down.
-The cost of a 1/2 bowl gouge is $50
-Useable flute length say 4 inches. Cost $12.50 per inch
-It can be ground say 50 times per inch. Cost $.25 per grind.
-Make a huge mistake and lose a 1/4 inch. Cost $3.12
This is a small price to pay... NOW to compare it with something else we use all the time... sandpaper ONE 2 inch disk is $.20
As a new turner what tools should I buy first?
First of all don't buy a lot of tools, stick with the basic tools to turn a bowl. As you learn more you will see a need to add another but don't waste your money on a set. The basic tools are a 3/8 & 1/2 bowl gouge, this is more than enough to turn a 12 inch bowl. The flute shape is a different question, if you ask 100 turners what shape to use you'll get 101 different answers. Ask me I'll say the V shape flute is the best but if you have a friend that is willing to teach you how to turn use the same shape that they do. I'll talk about this more in another question.
The tools are sold UNhandled, what do you recomend?
For my personal turning I like a custom made extra long metal handle to turn hats. You could make a wood handle in no time at all, Ron McKinley was kind enough to provide step by step instructions. (Click on HANDLES) Any aftermarket handle will fit the tools but here are a few I like.
Dave Peebles (see links page) Dave has a aluminum core vinyl wrapped handle for $35
Trent Bosch ( see link page) sells a aluminum handle that can be filled with shot to any weight needed.
Michael Hosaluk has a aluminum and a steel handle to fit your needs.
Cryogenics, why is it so important?
This is very involved so let's keep it simple. When steel is first hardened the structure of the steel changes to form austinite which is very brittle. We want to change the austinite that's brittle to a hard structure call martensite, to do this the steel needs to be tempered. This is done by heating the steel then allowing it to cool at a very slow rate. When the austinite is changed to martensite by tempering carbides are formed of each element of the steel. We want vanadium carbides to form and we want lots of them in our steel so after the first temper with heat the steel goes into a cryogenic treatment. Cryogenics is part of the tempering process but when the austinite is changed to martensite by freezing lots and lots of very fine carbides form called "eta" carbides, these are the carbides that we want.
This steel is tripled tempered with heat and a cryogenic treatment after the first temper, what is this? The first temper with heat changes some of the austinite over, then the cryogenics gets a whole bunch more and the second temper with heat is just to make sure all the austinite is gone. The third temper with heat changes all the martensite we just created to "tempered martensite" and that was the goal. It gets no better than this!
Shanks and Tangs?
First of all a shank is round like on a bowl gouge and a tang is flat on scrapers and skews.
Why is the shank on all bowl and spindle gouges are turned down to a common fractional size? This is because high quality tool steel is sold .015 oversize so the shank needs to be turned down to a common size to fit all the aftermarket handles and so a common drill bit can be used to bore a wood handle. Example; a 1/2 diameter tool will have a shank that measures .500
What is the shank length? On the 3/8 and ½ diameter tools the shank is 2 inches long. The 5/8 and ¾ diameter tools are 2-1/2 inches in length.
The 1” and 1-1/4” tools have a ¾ inch diameter shank that is 2-1/2 inches long.
All tangs are 2 inches long.
American or European standard to measure the tool?
We use the American standard to measure the tools, that is by the diameter of the steel. The European standard measures across the flute. In a world where we use both it does get confusing at times. Here’s a simple chart to show both.
American ----- European
3/8 ------ ¼
½ ------ 3/8
5/8 ------ ½
¾ ------ 5/8
7/8 ------ ¾
1 -------- 7/8
V Shape or U Shape that is the question!
If you ask 100 people the same question you’ll get 101 different answers. I prefer a V shape because the V shape flute can be very aggressive when roughing especially on green wood. When you need to remove a lot of stock when roughing a bowl or turning a hat where 99% of the blank ends up as shavings the V shape is the only way to go. The small nose radius is not grabby when entering a cut and can be used to create details. Because the wings tend to be longer on a V shape tool scraping is easily done on the outside of a bowl. In the past a V shape flute was known to clog with shavings, the design of this flute was changed so it doesn’t happen.
The U shape flute has some strong points especially when turning dry wood. The large nose radius allows the tool to shear the wood which is good to prevent tear out, the finish cut inside a bowl or long sweeping curves outside a turning are just two examples where this tool excels.
The grind?
All tools come sharpened with a basic grind done on a Oneway Wolverine jig. What this means is a useable grind that is a good starting point and can be modified after you receive the tool. Many grind the wings back on the bowl gouges to create a longer cutting edge or change the nose angle slightly.
Tell us about the company!
Thompson lathe tools started in 2005 when I decided to make my own turning tools, as a machine repairman by trade and a good machinist it was fun thing to do. What started as a simple project turned into something very involved, many one of a kind flute shapes were tested , the surprise discovery was the flute didn’t have to be as deep like the other tools on the market to work well. This went on until I found one that was a balance between the flute shape and depth of the flute that handled well and didn’t clog, with more steel under the flute it was a stronger tool. As I passed these tools out to my friends they started to ask for different shape flutes and diameters until the line of V and U shape bowl gouges was created.
I sent one tool to Mark Kauder to evaluate because he has compared the different steels in the past, It did well and his club placed a order… this changed everything and was the deciding factor to take it from a hobby to a business. Then it hit the internet! With only a few tools to sell and nothing else, one person after another took a chance on a unknown toolmaker and I thank each and everyone who did. Woodturners all across the nation helped created the company from the name to the products and made it what it is today… a corporation.
Things haven't changed much in the past 7 years except we have grown to a team of skilled employees to handcraft each tool one at a time.
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© 2007-2010 Thompson Lathe Tools
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