Odd question-
I'm fed up with the cheap plastic body on my Rotring Isograph pens being broken by colleagues in the office, so considering turning aluminium or possibly brass replicas, that I can then mount the standard isograph nibs in, for which I will need to cut relatively fine threads into, as well as deeply bore a long hole with a thin wall.
The threads look around 10.25mm (13/32"?) and approximately 0.67mm pitch (measured by eye and ruler at desk..) and will be cut into the ends of thin tube (11.5mm OD, 10mm ID, approx. 75mm long).
Does anyone have any comments about how they would go about producing these – I'm thinking that turning a tap from tool steel would be easier to reproduce multiple threads from (rather than thread cutting from a ground tool), and with minimal cutting depth from such a fine thread this wouldn't need anything too fancy by way of cutting geometry. probably cheaper and easier to start from some tube rather than solid bar and boring from scratch, but with such a thin tube- how do I prevent crushing it when holding- turn a wood blank to sit inside to resist compression- but the blank inside would then obstruct the final boring of the tube?