TMBR Metal Grub Screw Specs

Hi, Does anyone know the Thread and length of the Grub Screw in the TMBR Freemont?

Thanks in advance.

Just to clarify, By Grub Screw, I mean the Metal Axle inside the wooden axle.

I took mine out to sand and stain the wood, and have lost it.

Any help would be appreciated.