What are the sizes of collimation screws on Current-production Celestron optical tubes?
December 18, 2012
When you need to replace your collimation screws, please use the below for a refence of which screws to use:
Schmidt-Cassegrain Optical Tubes:
| Optical Size | Thread Specifications | Length |
|---|---|---|
| C5 | M3 x 0.5 | 10mm |
| C6 | M3 x 0.5 | 10mm |
| C8 | M3 x 0.5 | 8mm |
| C9.25 | M3 x 0.5 | 10mm |
| C11 | M3 x 0.5 | 12mm |
| C14 | M3 x 0.5 | 18mm |
EdgeHD Optical Tubes:
| Optical Size | Thread Specifications | Length |
|---|---|---|
| 8" | M3 x 0.5 | 12mm |
| 9.25" | M3 x 0.5 | 10mm |
| 11" | M3 x 0.5 | 12mm |
| 14" | M3 x 0.5 | 18mm |
