This is a tremendous resource focused on Leadholders and other forms of pencils used for drafting. It essentially is a museum of leadholders similar to the concept we are working to build up with our Pencil Wiki Library here on Pencil.com for woodcased pencils. This site does have a nice section on woodcased drafting pencils and where appropriate we link to relevant pages there from like items in our Pencil Library.

Wondering what a leadholder is? In their own words:

"Leadholder (or Lead Holder) can be broadly defined as any durable instrument that is designed to hold and be refillable with consumable pieces of graphiteⁱ so that the graphite can be conveniently used for drawing or writing. Within this definition there are subsets such as porte-crayons, mechanical pencils, and drafting leadholders. This website is primarily concerned with drafting leadholders, which are commonly called by draftsmen in the US as simply leadholders."