Some of you may find chapter four enlightening.
As someone who uses both metalwork and woodwork lathes I find the use of misleading names for chuck components quite frustrating at times.
“The Scroll Chuck
The scroll chuck was invented in 1840 and has been a work holding standard in industry ever since. Many different types are available with anything from two to six Jaws. Three and four jaw versions are common and are manufactured with single or two piece jaws.
Using two piece jaws increases the versatility of chucking systems.
It was perhaps nearly 150 years later that one of the wood turning tool manufacturers realised that this system could also be used on a wood turning lathe. Up until this point several collet chucks had been produced especially for wood turners but the design never stood the test of time and production ceased, replaced almost entirely by the scroll chucks we see today.
Most wood turning chucks are made specifically for the purpose but this has not always been the case. Indeed you can still buy the “Versachuck” from Beaufort Ink which is identical to those used on small Engine lathes apart from its Jaws.
Terminology for scroll chucks seems to cause some confusion for wood turners at times. This has not been helped by some manufacturers renaming the traditional parts of a chuck with their own terms. For over 180 years the term Chuck Jaws has been universally understood by machinists. This remains the case even with two part jaws, the bolt on top parts being called “Top Jaws”. Confusingly wood turning chuck suppliers call the Jaws “slides” or “carriers”.
The bolt on top parts are often more correctly called Accessory Jaws.”
Sometimes suppliers actually use the correct terms:
