MWF FEED
25th February 2022, 11:30 PM
Among a Whitworth tap/die set were these oddity:
IMG_2653.jpg (https://metalworkforums.com/attachment.php?attachmentid=397273&d=1645789159)
30mm diameter dies, with holder.
3 die and 2 taps marked 10 26.
Checking with thread gauge revealed 26TPI.
Checking with vernier verified 10mm.
Looking on exhaustive thread charts shows 10-24 (UNC) and 10-28 (ASME) –
both with 60° form – but no 10-26???
Checking again, against bright light, with thread gauge shows it seems to be 55° !!
(oh, and there is a 7/16 26 die in there. CEI?? Never heard of it)
There are all sorts of interesting threading sizes that have been lost in time.
This is just the first time I have seen evidence
Attached Images
https://metalworkforums.com/images/attach/jpg.gif IMG_2653.jpg (https://metalworkforums.com/attachment.php?attachmentid=397273&d=1645789159) (231.4 KB)
Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=207807&goto=newpost)
IMG_2653.jpg (https://metalworkforums.com/attachment.php?attachmentid=397273&d=1645789159)
30mm diameter dies, with holder.
3 die and 2 taps marked 10 26.
Checking with thread gauge revealed 26TPI.
Checking with vernier verified 10mm.
Looking on exhaustive thread charts shows 10-24 (UNC) and 10-28 (ASME) –
both with 60° form – but no 10-26???
Checking again, against bright light, with thread gauge shows it seems to be 55° !!
(oh, and there is a 7/16 26 die in there. CEI?? Never heard of it)
There are all sorts of interesting threading sizes that have been lost in time.
This is just the first time I have seen evidence
Attached Images
https://metalworkforums.com/images/attach/jpg.gif IMG_2653.jpg (https://metalworkforums.com/attachment.php?attachmentid=397273&d=1645789159) (231.4 KB)
Read the full thread at metalworkforums.com... (https://metalworkforums.com/showthread.php?t=207807&goto=newpost)