19-02-2021, 01:37 PM
The conduit thread is mentioned in one of the standard texts (SBG or perhaps Williams).
I looked for that dusty shelf and years ago even my local ironmongers, who could rustle up drawer full of BSF box spanners in all sizes, drew a blank. Easy enough to make one in brass though.
The few times that I've drilled and chipped one out it's not been to much advantage and I haven't had buckets of crud come out. Proper chemicals, administered before machining, is by far the best approach.
I looked for that dusty shelf and years ago even my local ironmongers, who could rustle up drawer full of BSF box spanners in all sizes, drew a blank. Easy enough to make one in brass though.
The few times that I've drilled and chipped one out it's not been to much advantage and I haven't had buckets of crud come out. Proper chemicals, administered before machining, is by far the best approach.