I am trying to mount the Graflex M-1 solenoid mount (#2761) on my Crown Graphic lens board, but my mount did not come with the lens board mounting screws.

Does anyone know what the thread is? I am thinking it is #1-64, but I want to be sure before ordering screws (as they come in 100/pk).

I wish that Graflex didn't use such tiny screws where a more common screw size would have worked just as well.

Regards,

Peter

Graflex part number: 30901P1- screw, machine (special) for the clamp;
31190 - screw, machine (special) quantity 2 for the lens board mounting.
30907 for the M3 mount.

They're "special" due to the head being larger than normal.

I have a HR solenoid on a metal board from a 1928 Speed Graphic. Its mount screw is 1-64 x 1/8 with an oversized head.

Thank you for the reply. I knew the Graflex part numbers, but they rarely gave dimensions to their screws, especially if they were categorized as "special".

I measured the thread pitch of the mount's clamp screw (which I have), which is .4mm. This corresponds to 64 TPI. So is likely #1-64 as a #2-56 screw is slightly too big, and a #0-80 is slightly too small.

I verified that the screw thread size on the Graflex M-1 mount is #1-64. I expect that the other mounts that look similar to the M-1 (the M-2) are also #1-64 thread.

Graflex Corp. sure didn't go out of their way to make things easy for us. In my experience, 1-72 is more commonly found than 1-64; in fact, 1-72 is pretty standard in the model railroad hobby. For years now I've owned a tap set consisting of 00-90, 0-80, 1-72, and 2-56, and hardware (screws, nuts, washers, etc.) in those sizes are (or were) commonly available in model railroad hobby shops, and in small quantities---you didn't have to buy 100 of them to get the two or three that you needed. Ah, the memories....

Yes, not the common thread size for #1. "64" is considered the "course" thread for #1 screws.

My first thought was to check the local hobby shop. Since almost everything is made in Asia anymore, the tiny screws they had were mostly metric, They only had #0-80 and #2-56 in imperial threading.