- Joined
- Jul 11, 2014
- Messages
- 496
Machine thread that is. I came face on with my ignorance recently. 
I was looking to add a metal hold-down strip to two of my vernier calipers (both old Starrett tools). The piece that holds the 'depth' bar down was missing. Now I knew these were small screws, I'd only been looking at them for a couple of years. No need to fix them as I had other verniers in my collection and other projects to do also. I've seen small screw in electronic devices (e.g. Computers, phones, anything with transistors, my glasses, etc.) so I shoulda known this but I have always thought a number 4 screw was the smallest (denying the evidence right in front of my eyes).
Number four was way bigger than the hole would take. Hmmmm. Started looking around the shop for smaller screws and ran up on a box of "Brownel Fillisterhead screws". Got em at a 'groj sail' sometime back but didn't investigate to see what I had. Lo-n-Behold! 
They start at 0-80 then go up, 1-72, 2-56, 2-64, 3-48 & 3-56 before they get to a number 4. Hmmmm, ignorance may be bliss but not in my case. Unfortunately none of them would fit.
What is this, do Starrett tools use metric thread?
On the brightside, which I am not, I did learn something so I ain't dead yet.
Aside from that, how do they cut them? I couldn't cut any of the small threads on my lathe, just don't have that skillset. Someone musta cut the first on a lathe
somewhere.
Who woulda thunk it?!
I was looking to add a metal hold-down strip to two of my vernier calipers (both old Starrett tools). The piece that holds the 'depth' bar down was missing. Now I knew these were small screws, I'd only been looking at them for a couple of years. No need to fix them as I had other verniers in my collection and other projects to do also. I've seen small screw in electronic devices (e.g. Computers, phones, anything with transistors, my glasses, etc.) so I shoulda known this but I have always thought a number 4 screw was the smallest (denying the evidence right in front of my eyes). Number four was way bigger than the hole would take. Hmmmm. Started looking around the shop for smaller screws and ran up on a box of "Brownel Fillisterhead screws". Got em at a 'groj sail' sometime back but didn't investigate to see what I had. Lo-n-Behold! They start at 0-80 then go up, 1-72, 2-56, 2-64, 3-48 & 3-56 before they get to a number 4. Hmmmm, ignorance may be bliss but not in my case. Unfortunately none of them would fit. What is this, do Starrett tools use metric thread?
On the brightside, which I am not, I did learn something so I ain't dead yet.
Aside from that, how do they cut them? I couldn't cut any of the small threads on my lathe, just don't have that skillset. Someone musta cut the first on a lathe
somewhere.
Who woulda thunk it?!
