Mirrors Sextant mirrors have a limited lifetime before needing resilvering or replacement. Estimates range from 2 to 6 years in marine service. While resilvering is an option, good quality is hard to achieve. New mirrors are not much more expensive, and are shown below.

Horizon Mirrors
Astra IIIB – 51mm diameter with mirror frame
Traditional (half silvered) #0504R    $75
Whole Horizon #0503R    $75

Other sextants (Cassens & Plath, C. Plath, Tamaya, Freiberger) 57mm, frame not included
Traditional (half silvered) #0703    $95

Index Mirrors (56 x 42mm)
Astra IIIB no frame #0517D    $80
Astra IIIB with frame #0516D    $95
Other sextants no frame #0517D    $80

The 3.5 x 40 scope supplied with the Astra IIIB has become a Universal Scope, and has been sold with Cassens & Plath, C. Plath and Tamaya sextants. To determine the fit on other sextants use the diagram shown below. (NSN 6605-012533442)

Universal Telescope #0508    $120

To determine the fit on another sextant, the ends of the fork from its regular scope should approximately match the outlines to the right.forkends

Replacement Parts

Index Mirror with NO Frame


Replacement Parts

Universal Telescope


Replacement Parts

Index Mirror with Frame


Replacement Parts

Mirror Adjustment Wrench