The early 9600 is essentially identical to the Locktite 9400, but it has modified clutch jaws to accept a special, flat lead.

The patent holder for this pencil is actually the cold war beneficiary General Dynamics, not A.W. Faber.

This type of flat lead and holder was developed with lofting in mind. Lofting is, to be brief, the conversion of a small scale drawing of a machine part to a full size one from which patterns can be made. The full scale drawing is layed out directly on the pattern material which can be metal or wood or what-have-you. The practice originated in shipbuilding and was carried on into the aircraft industry. The flat lead can lay down a perfectly uniform line without the need for repointing the pencil. Standard 2 mm round lead was of no use in this application due to the oftentimes rough drawing surface wearing the point of the lead flat immediatley.

Although developed with the very specific purpose of lofting in mind, the lead for these pencils is, I believe, the first graphite pencil lead formulated with a synthetic polymer based binder rather than the traditional kiln-fired ceramic binder. It was the development of polymer-based lead by the German A.W. Faber company that made possible the development of "micro-lead" pencils of 0.5 mm diameter, which would later be popularized by the Japanese company, Pentel, and are today ubiquitous.

I've been doing more research and I haven't found any good evidence to suggest polymer leads as used for thin lead drafting pencils were developed by A.W. Faber. Further, I do not believe the Faber Castell flat lead uses a polymer binder. It is a ceramic based formulation like round leads. I am currently rewriting the History of Thin Lead Drafting Pencils which, when finished, will have much more to offer on this topic.


isolated collet and lead


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