this is a coincidental post not dissimilar to the one posted by LordGimmick ...
I'm restoring a 100+ year-old Swiss-made (Lienhard) brocading machine and it is full of machine screws that have a mysterious diameter and pitch scheme. I've posted a picture of one of them, and there are many of these in the machine, to show the dimensions. I hope the picture comes out big enough ...
Here they are:
Extrapolated V-thread major diameter = ~.230 in (5.84 mm)
Actual major diameter = .222 in (5.64 mm)
pitch = ~ 22.94 tpi (1.11mm)
I've looked at all the thread tables I can find: metric, BA, BSW, BSF, BS ISO, Thury, etc. and, of course the Unified tables, and unless I've missed something, nothing matches. I suspect this screw thread scheme pre-dates all of the tables I have.
Many of the screws are damaged and need replacement so I'll need to find some or make them if I must.
Has anyone got a hint on what scheme these may fall under?
I predict a response or two: "Make 'em!" Even if I can't find them and have to make them, I'd like to adhere to a standard that suits it's origin if possible. Many of them have long engagements of 3/4 inch so an approximate standard has to be pretty close.
Cheers,
Rich
I'm restoring a 100+ year-old Swiss-made (Lienhard) brocading machine and it is full of machine screws that have a mysterious diameter and pitch scheme. I've posted a picture of one of them, and there are many of these in the machine, to show the dimensions. I hope the picture comes out big enough ...
Here they are:
Extrapolated V-thread major diameter = ~.230 in (5.84 mm)
Actual major diameter = .222 in (5.64 mm)
pitch = ~ 22.94 tpi (1.11mm)
I've looked at all the thread tables I can find: metric, BA, BSW, BSF, BS ISO, Thury, etc. and, of course the Unified tables, and unless I've missed something, nothing matches. I suspect this screw thread scheme pre-dates all of the tables I have.
Many of the screws are damaged and need replacement so I'll need to find some or make them if I must.
Has anyone got a hint on what scheme these may fall under?
I predict a response or two: "Make 'em!" Even if I can't find them and have to make them, I'd like to adhere to a standard that suits it's origin if possible. Many of them have long engagements of 3/4 inch so an approximate standard has to be pretty close.
Cheers,
Rich