Woodturning A-Z

Cam locking.
An eccentric pivoting lever operated mechanism is used to give powerful clamping force. Often used to clamp the "banjo" to the bed.

Capacitor start.
This is added to a single phase motor to give extra starting torque. Not needed on three phase motors.

Carbide Cutting Tools.
Not to be confused with high speed steel, an example is cemented tungsten carbide as used for tipping saws, router cutters etc. This is not a steel at all, it is powdered carbide fused into a solid with a cobalt binder. It will not take such a keen edge as steel.

Carbon Steel.
Steel which can be hardened by heat treatment and which becomes hard because of its carbon content. It is just as hard as HSS and takes a very keen edge. It is still used by some turners because of this. See high speed steel (which contains carbon but depends on other alloying elements for its cutting performance)

Carborundum.
Silicon carbide used for abrasive. Silicon carbide wheels (called "green grit" because they are green in colour) are used for sharpening cemented carbide tipped tools but they are not recommended for HSS tools. The Carborundum company also make aluminium oxide wheels - which has been known to cause some confusion! The grey wheels on cheap grinders are corundum (impure aluminium oxide) not carborundum.

Cast Iron.
This can be recognised by the moulded dimpled surface and lumpy thick sections. Although less dense than steel, more is used to achieve the desired strength and cast lathes are nice and weighty. The consequence of the thick section is massive rigidity and very little vibration.

Centre Points.
The drive centre and tail centre points.

Centre.
Used at the headstock end (drive centre) and at the tailstock end (tailstock centre) to support the wood and hold it in place.

Centrifugal Switch.
A switch inside a capacitor start motor which disconnects the capacitor when the motor runs up to full speed.

Chuck work.
Projects which require hollowing or drilling such as bowls, goblets are held in a chuck. The term is sometimes restricted to projects having the grain running axially such as a goblet or vase.

Chuck.
A device used to hold a piece of wood firmly to the end of the spindle. If a piece of wood cannot be held between centres it is held in a chuck.

Cobalt alloy.
Cobalt is used in some grades of high speed steel.

Cobalt high speed steel.
A superior grade of high speed steel.

Collet. A type of chuck jaw.
A collet set is closed by the action of a tapered chuck ring.

Continental spindle gouge.
All gouges were once this type - forged from strip not machined from round. They have a more regular thickness and are easier to use and sharpen (my opinion).

Copy turning.
Making identical replicas of chair spindles etc.

Counterbore.
A kind of drill bit which has a pilot which follows a pre-drilled hole to open it up to a bigger size. Will also function as a drive centre. Handy for making lamps.

Crotch Figure.
A lovely grain pattern found where two limbs of the tree divide.

Cup centre.
Now denotes the hollow centre used to guide the lamp auger. A ring centre is similar - the centre point is surrounded by a small sharp edged ring which penetrates a little into the end of the wood and acts as an efficient bearing. It is essential to lubricate with wax or oil.

Curved tool rest.
Used to reach into a bowl to reduce tool overhang.