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The Basics of Lathe / Woodturning Tools

3.3K views 8 replies 7 participants last post by  Jonzjob  
#1 ·
Woodturning Tools

I wanted to write about turning tools and sharpening, and that is what this post is about. Keep in mind that there are two main types of woodturning: spindle turning (legs, pens, and other "long" items) and face turning (bowls, platters, etc.).

Woodturning tools come in many sizes and lengths. Some are "full size" while others are not much larger than a screwdriver, and everything in-between. Many woodturners have an assortment of different tool types. If you think about how fast lathes rotate, your cutting tools will plow through miles of wood in a short time. To keep working, woodturners must stop turning to sharpen their tools as needed.

Categories of Woodturning Tools

Woodturning tools come in two very different and distinct categories:
  • Traditional high speed steel (HSS) woodturning tools
    • Requires sharpening tools
    • Preferred by most professional woodturners, but not all.
  • Carbide tipped turning tools
    • Uses replaceable pre-sharpened tips, which reduces initial effort and cost
    • Used differently than HSS turning tools.
    • Some will argue that they are easier for beginners to get decent results, but can limit future skill growth. I do not have an opinion.
I like to use both types and have no issues with switching between them while turning a project. My tool holder is usually loaded with both types of turning tools. I know other woodturners who use only one type or the other. It is a matter of personal preference.


Traditional High Speed Steel (HSS) Woodturning Tools

Traditional HSS turning tools have been used for a very long time. Professional woodturners and demonstrators use them much more often than carbide tipped tools. Here are the main types of HSS turning tools:
  • Roughing Gouges (Spindle Turning) - A roughing gouge lets you turn a rough unbalanced spindles into a smooth, balanced cylinder to start.
  • Spindle Gouges (Spindle Turning) - Use spindle gouges to add the finer details - coves, beads, V grooves, etc.
  • Skew Chisels (Spindle Turning) - The skew chisel has an angled edge (straight or gently curved). A skew chisel can be used to make coves, beads, V grooves, etc. They take a lot of practice, but can yield very smooth, "no sanding required" turnings. Some woodturners gravitate to them, others avoid them.
  • Parting Tools (Mostly Spindle Turning) - They do a variety of cuts and functions, but are often used to cut off unwanted ends when your turning is complete.
  • Bowl Gouges (Face Turning) - Heavy duty gouges for turning bowls and hollowing them out. (Caution: Do not use roughing gouges or spindle gouges for face turning. That is what bowl gouges are designed to do.)
  • Scrapers (Face Turning) - You present this tool flat and use it as a scraper.
All of the tools above come in different sizes and variations. Be aware that US woodturning gouges are measured differently than the same tools made in the UK. In the US, published gouge sizes are the outside diameter of the tool. The same UK-made tools publish the inner flute size instead. The simple rule is "Subtract 1/8 inch from the US gouge size to get the UK size."

My UK-made bowl and spindle gouges are called "3/8 inch". The same exact tools would be called "1/2 inch" if they had been made in the US. I suspect that most sources use the US standard, but do not know that for sure.
-> When you are looking at gouges online, be sure you know which size spec they use. You need to know which brands of gouges are made in the UK (Sorby, Crown, etc.) and spec'd accordingly.

Sharpening HiSS Tools

Even though they are made of very hard steel, HSS turning tools cut through a lot of wood and need frequent touch-ups. The professional demonstrators pause and sharpen their tool while they turn, sometimes as often as every few minutes. There are way too many choices for sharpening HSS turning tools and a lot of hype around them, so sorry.

-> CAUTION: Do not use the common high speed grinders that many people have already. They will heat up and damage your turning tools before you can blink. The damage leaves a brittle edge that does not hold sharpness. Fixing them is a painful time-consuming challenge. Do not use high speed grinders for sharpening turning tools or you will damage your tools.

-> For HSS turning tools, I recommend a slow speed grinder with a jig to make sharpening repeatable. The Wolverine jigs and knockoffs of them are popular. If you can afford CBN wheels, they are expensive, but nice to have.

Avoid wet grinders, even Tormek. I wish I had the sharpening tools I recommended in the paragraph above, but I have a wet grinder instead. I do NOT recommend wet grinders. I wish I had not bought the one I use (Grizzly) and plan to replace it, but still try to get by. Tormek is the gold standard of wet grinders. I use Tormek jigs on the Grizzly and still have repeatability issues matching edges for a quick touch-up.
-> Wet grinders are way too slow, period. Even Tormek. It can take hours to fix an edge with a wet grinder like mine, especially if you mess up a skew chisel. Someday I will switch, but I bought the one, and will live with it for now. Don't make the same mistake if you decide to use and sharpen HSS turning tools.

There are other kinds of sharpeners, like Sorby's ProEdge. It is an expensive, nice sharpening tool. I gave a demo with one once, and had issues with it. I blame the issues on my own lack of experience with it. Some people like them a lot, others not so much. The belts are expensive.

Shop around, but I still believe that a slow speed grinder with a good jig is the best solution for most woodturners.


Carbide Tipped Woodturning Tools

Carbide tipped turning tools are a newer alternative to high speed steel (HSS) tools. They are different than HSS tools in many ways - how they are used for turning, how they are sharpened, and more. They use very hard, pre-sharpened carbide tips. The carbide tips attach to the end of the tool with a screw. These are the most common shapes for Carbide turning tools:
  • Round
  • Square
  • Square Radius
  • Diamond
In general, a turning tool is made to fit one shape of carbide tip only. Because of the shaped support behind the carbide tip, you cannot mount a diamond tip in a tool made for round tips. If you have all four carbide tip shapes mentioned above, you will want four matching tools. The only exception I found is sometimes a square tip will fit awkwardly in a square radius tool (but not vice versa). I do that, and use three tools for four tip shapes.

The square and square radius tips look very similar, but they are different. Square tips can cut unwanted lines at each corner, and I believe that square radius tools are easier for beginners to control. (At the same time, square tips can be nice for fast roughing down to a cylinder.)

Diamond carbide tips come in both rounded points and sharp point styles.

Many carbide turning tools sets include a HSS parting tool. You can sharpen it with a flat diamond plate or sharpening stone. You do not need a special slow speed grinder just for that one HSS tool.

I have heard many times that carbide turning tools can only be used in scraping mode. I ignore that comment, because sometimes I treat them like HSS tools and cut ribbons with them, too.

Carbide tips cannot reach the same ultra-sharpness as HSS turning tools, but they come very close and it does not really matter. In my personal opinion, carbide tips have four sharpness stages:
  1. Very Sharp - This is when they are new. I wish this phase lasted longer. :-(
  2. Sharp Enough for Good Woodturning - Because carbide is so hard, this stage lasts a long time.
  3. Not Cutting as Well as Expected; Is it ME or the Carbide Tip? - The woodturning is not going as well as you would expect, but you don't feel like stopping and dealing with the carbide tip. You should sharpen (rotate) or replace the tip at this point, but you keep working anyway.
  4. Definitely needs Sharpening or Replacement - Too late. You should have done this in stage 3. :)
There are many brands and types of carbide turning tools. Do your homework and shop around. Some have a single handle with a quick change for different shafts. If you buy one of those, make sure it is truly quick and easy to change from one tool shaft to another. Otherwise, you may want several tools in a set, each with a different tip shape.

Easy Wood Tools (EWT) is well regarded. I mention them because they have a patent on their negative rake carbide cutters, which are only made by EWT and only fit their tool handles. Regular "flat" carbide tips also fit their handles. You cannot use their negative rake cutters in another brand of handle. I wish I had bought EWT carbide turning tools instead of the Rockler tools I use, for those negative rake cutters.

You can buy carbide tips for less money from third-party source. In my opinion, they are just as good as the name brands, for much lower cost. AZ Carbide is a source I have used and recommend.

Sharpening Carbide Woodturning Tools

If your carbide tip is not cutting as well as you expect, that edge may be dull. Sharpening is easy:
  • Rotate the carbide tip in the tool handle to expose a fresh sharp edge.
    • Round: Turn it enough that the dull edge is out of the way.
    • Square and Square Radius: You have four sides to use.
    • Diamond: You have two sides to use.
  • When all edges are used up and dull, replace the carbide tip with another one.
It helps to mark the starting point when you install a new carbide tip so you will know when the tip is used up. Some tips come pre-marked with a dot or other indicator. Otherwise, I use a Sharpie marker to make my own dot, always in the same corner to remember.

Sharpening Carbide Tips Yourself
You can restore an edge on ordinary carbide tips by flattening the back on a diamond stone. Just lay the tip flat side down and swirl it evenly on the stone. It won't be quite as sharp as a new carbide tip, but it is good enough for me. Sharpening on a diamond stone may remove the "starting point mark" left by the manufacturer or your Sharpie marker.


Omitted
  • Discussion of lathe safety.
  • Discussion of how turning tools are used.
 
Discussion starter · #3 ·
Very nicely written treatise. Like many people, I started off with the EZ Wood tools, because the learning curve wasn’t as steep as HSS. As I became more proficient, I now mostly use HSS tools as I get a cleaner cut. I haven’t been able to get EZ Wood tools to peel a ribbon, but I’m mostly spindle turning dry wood. I still use the EZ Wood tools for certain operations.

I’m curious for your thoughts on the Hunter Hercules and Osprey. I bought one on a lark and it really seems to fill the gap between EZ Wood tools (forgive me if I call them scrapers) and well honed HSS spindle gouges.
Thank you. It was too long, so I moved it from the other thread to this one. I originally posted it in this thread:

I don't know much about Hunter Hercules and Osprey. I have seen others using them, but that's the extent of it. Hopefully others with more experience will chime in.
 
Discussion starter · #7 ·
You are right, but "traditional shape HSS tools" feels too long to write. Many here are careful with terminology and know the difference between high speed steel and carbon steel turning tools. Sometimes it helps to use imprecise terms like "traditional high speed steel" to avoid overwhelming newbies with detail.

Gouges have evolved into what we call "traditional" shapes. To this day, people still experiment and argue about different shape grinds for their gouges.

The target audience for this thread was newbies who are starting out in woodturning and are trying to choose which basic turning tools to buy. Another motive was to avoid leaving a long, distracting post in a different thread about choosing a lathe.