Drawing Numbers ??

[JGaynor]

The "D" indicates the size of the sheet of paper used by the draftsman. Basically a filing measure - a small part could be drawn on a small sheet. Larger components required larger drawings. If a design change became necessary knowing the drawing number would tell the engineers/draftsman what cabinet or drawer where the original could be found. (now of course probably on line!)

The "core" (in your case 35448) of the drawing number also became the seed of the stock number for spare parts ordering and control.

Regards,
Jim