SIGMA - Sigma 411NA8 Parts

Comprehensive parts catalog for the Sigma 20mm F1.8 D EX DG Aspherical RF lens (model 411-NA8) designed for Nikon AF camera bodies. This technical reference document provides essential documentation required for maintenance, repair, and servicing of this high-performance wide-angle lens. The catalog presents a complete component nomenclature systematically organized with precise part numbers and designations provided in both English and Japanese nomenclature. Detailed technical diagrams illustrate the lens assembly architecture, clearly showing the positioning of each component within the optical system structure. The documentation encompasses critical components including the main focus cam unit, S-gear ring, focus roller, focus guide screw, cover ring unit, inner baffle unit, AF gear unit, main PCB unit 411NA8, masking sheet, and lens hood. Each component listing includes accurate quantity requirements and reference numbers, enabling straightforward ordering of replacement parts through authorized Sigma distribution channels. This catalog serves repair technicians, authorized service centers, optical maintenance professionals, and knowledgeable users requiring component identification or replacement for their photographic equipment. The clear visual representations and comprehensive parts indexing make it an indispensable resource for anyone performing lens maintenance or component sourcing.