Choose your weapons - Wood Turning Tools Part 1

Choose your weapons - Wood Turning Tools Part 1

In this first of a two-part series I will be introducing the basic woodturning tools to you. I will focus on traditional tool steel turning tools in this article and on carbide wood turning tools in the second part. 

Tools (Gouges /Chisels/Scrapers) for shaping and cutting the work piece

Fig. 1: Hendry Taylor/Hamlet woodturning tools

There are many different types of woodturning tools for cutting and shaping the wood piece once it has been secured on the lathe. Although they are often called “chisels” this is a bit of a misnomer as there are four main sub-groups of woodturning tools with “chisels” being just one of them. The four are:

• Gouges
• Chisels
• Scrapers
• Parting Tools

These tools are generally made from High-Speed Steel (HSS) for ease of sharpening. The steel is hardened which retains a sharp edge longer than softer, non-heat-treated steel. In keeping with one of the themes of this series of blogs, it is better to invest in the higher quality tools from known brands like Robert Sorby, Henry Taylor/Hamlet and Crown rather than the low budget tools made from poorer quality low budget steels. These tools will never retain a sharp edge as long as those made from high quality steels. As it is, woodturning tools need frequent honing – as often as every 15 minutes when shaping particularly hard wood. You can just imagine how poorly a poor quality steel chisel will hold up under these circumstances.

Advances is metallurical hardening technology are producing superior quality steels for HSS tools, like Kryogenic heat treatment process, H28  and Pro-Pm Powder Mettallurgy steel, these treatments not only produce a longer lasting edge but could be honed to a very fine sharp edge.

Gouges

A gouge is a chisel with a curved profile and cutting edge. Woodturning gouges have the bevel ground on the outside only and come in various styles and sizes. They should not be confused with bowl gouges which have some similarities.

Spindle Roughing Gouge:
This is a heavy walled gouge has a wide U-shaped blade with a shallow curvature. The roughing gouge’s wide U-shaped cutting edge allows it to remove large amounts of wood very quickly. The bevel is typically ground to between 40° and 45° and must be flat across the cutting edge. It is used for initial cutting and shaping of wood held between centres (spindle work) including removing the 

corners and roughness when rounding and balancing square or irregular shaped stock. The Spindle Roughing Gouge should never be used for hollowing bowls as the coners either side of the cutting edge will quickly catch when cutting in to concave shapes, resulting in a broken gouge and damaged workpiece at best or a high-speed projectile at worst.

Fig. 2: Hamlet 3/4"(19mm) Spindle Roughing gouge

• Spindle gouge:
  Spindle gouges have a rounded tip and shallow curve, and the bevel is ground to an angle anywhere between 30° and 40°. The rounded shape is called a fingernail profile.  The spindle gouge was developed for cutting narrow details like beads and coves. The spindle gouge can also be used for a finishing cut, however, is more useful for finer shaping and detailed work.

Fig. 3: Note the fingernail shape of the spindle gouge when viewed from above.

Fig. 4: The different decorative elements that can be achieved on a spindle.

Bowl gouge:
Bowl turning gouges are longer and stronger than spindle gouges as they are often used overhanging the tool rest when cutting deeply into the hollow of a bowl. The bowl gouge has a deeper flute section with either a U or a parabolic shape to allow for back swept wing sections to be ground. These “wing sections” are used for cutting and shaping the outside of a bowl and for hollowing the inside of the bowl. Bowl gouges can be ground at various angles, however 50° and 60° with a rounded fingernail shape is good for most face work and bowl turning.

Fig. 5: A Robert Sorby Deep Flute Bowl Gouge. Note the parabolic shape of the flute.

Skew Chisels

Fig. 6: The standard skew chisel

A standard skew chisel has a rectangular section and has a flat cutting edge that is skewed to one side. The angle of a skew chisel’s cutting edge is typically 45°. The bevels of its cutting edge are usually ground to somewhere between 25° and 55° (12.5° and 27.5° on each side).

Fig. 7: Some of the profiles of the skew chisel.

The skew chisel has evolved into various cross-sectional profiles from the standard rectangular to oval and round sectional shapes with straight to radiused cutting edges all with their own advantages.  It is a very versatile tool that can be used for scraping, shear scraping and planing cuts. They are great for cutting beads, vee cuts, cleaning up the end grain and cutting tenons for a 4-Jaw chuck.

Scrapers

The scraper is used in woodturning to create a final smooth finish to inside of  a hollow form or on the outside of convex surfaces positioned with its wide flat edge on the tool rest and held on the centre line with handle in a 50° upward position to reduce the angle to the wood to less than 90° to avoid a dangerous catch.

Producing a Negative rake bevel above the cutting edge affords a safer angle to the wood, reducing the possibility of a catch.

Scrapers needs to be strong because it is likely to have to work a long way forward over the tool rest which results in high leverage forces. A top-quality  scraper has a thick blade with a heavy rectangular cross-section the cutting edge and typically has a single bevel of between 60° and 65°. The humble Scraper has also evolved and are available in many different shapes and sizes although square, round and half-round are the most common.

Round nose scraper:
Round nose scrapers are used to shear and smooth the surface of a workpiece and are frequently used in faceplate turning to smooth the inside surfaces of bowls and cups.

Fig. 7: The Hamlet round nose scraper.

The square scraper:
The square scraper is frequently used to smooth the outside of a spindle workpiece. This scraper’s blade has a cutting edge which is square to its side edges with a single bevel, typically at 60-65 degrees. Its blade has a thick, heavy cross-section

Fig. 8: The Hamlet square scraper

Half-round scraper:
A half-round scraper is used for smoothing surfaces, frequently the internal portion of a bowl or other hollow form. The half-round scraper blade has one flat side and one curved side. Like many scrapers, the blade is typically thick with a heavy rectangular cross-section and a single ground bevel of between 60° and 65°.

Fig. 9: The Hamlet half-round scraper

Parting Tools

The parting tool does what it is described as, to part or cut the wood either in half or to part off a finished work piece held in a 4-Jaw chuck.

Standard Parting tool:
The basic standard type of parting tool with a parallel, non fluted rectangular section - the small 3mm size will do most parting jobs. It is advisable to be aware that the flat sections of the tool will create friction on either side against the wood being cut, this generates heat and will burn the wood. The solution to this is to make a second cut next to the first one as you deepen the cut, this will create a small distance between the tool and the wood and will alleviate the friction and heat created.

Fig. 10: Standard parting tool made by Hamlet

Diamond Parting Tool: A diamond parting tool has two bevelled sides with a pointed tip. The diamond-shaped cross-section reduces friction between the sides of the tool and the parting cut. This works because even though the cutting edge are in full contact with the workpiece, the bevelled sides of the blade are only in minimal contact at their widest (middle) points.

Fig. 11: A diamond parting tool made by Robert Sorby

Fluted Parting tool:

Fig. 12: A fluted parting tool made by Robert Sorby

The blade is similar in shape to the plain parting tool, with the exception that it has a groove that runs the length along the longest bevel of blade, this creates a very sharp edge and makes a clean cut. These fluted blades come in a wide range of thicknesses allowing you also cut beads of various sizes.

Knife Parting tool:
This flat rectangular parting tool (sometimes called a “knife parting tool”) is used in spindle turning to make thin cuts into the workpiece. The plain parting tool’s blade is typically shorter than other parting tools and has an angle between 35 and 40°. The blade is positioned with its narrow edge on the tool rest and bevel up.

Recommended Basic starter set

As you will have realised by now the range of wood turning tools is vast and most turners have a wide array to meet the needs of their specific projects. A basic starter set could include the following tools:

• Spindle Roughing Gouge 3/4" (19mm)
• Spindle gouge with fingernail profile about 3/8" (9.5mm)
• Parting tool 3mm
• Bowl Gouge 3/8" (9.5mm)
• Round Nose Scraper 3/4" (9.5mm) or 1" (25mm)
• Square Ended Scraper 3/4" (9.5mm) or 1" (25mm)