Been looking a this thing sitting on my desk for months, meaning to see
if I can find tips for it. Lufkin of course being long out of business,
means trying to find something current and compatible.
My best guess is the thread is a 3-56. Tap drill for that is .082, I can
get a .085 pin in, barely. 3-48 is .078 and that's way loose.
Also, I can thread a 2-56 tap clear to bottom and never feel any binding
from dissimilar pitch. I have a 3-48 roll tap, and it wants to start,
but binds almost at once.
So, MSC lists replacement points for Starrett models 818, 18A/18AA, and
18B; General #78, 79, and one for "Made in USA".
Anyone happen to know, or can verify, if any of these have a 3-56 thread
for the replaceable tip?
- posted 11 years ago