Bausch & Lomb Microscope Objective Lens Retaining Ring Threaded Aluminum Part

Bausch & Lomb Microscope Objective Lens Retaining Ring Threaded Aluminum Part

This is a threaded aluminum objective retaining ring (lens collar) from Bausch & Lomb, used to secure an objective lens or optical element within a microscope nosepiece or body tube. The ring features external threads for mounting, a knurled outer grip band with notched segments for hand-tightening, and an inner lip (with a black rubber or felt cushion ring on one face) to seat the optical element securely without scratching. A small B&L mark is visible on the rim, confirming Bausch & Lomb manufacture.

Specifications & What's Included

• Brand: Bausch & Lomb
• Type: Objective lens retaining ring / threaded lens collar
• Material: Machined aluminum
• Thread type: External threads for microscope body/nosepiece fitment
• Outer grip: Knurled notched band for hand-tightening
• Inner face: Black rubber or felt seating lip to protect the optical element
• Includes: Ring only — no additional hardware or accessories

Applications

Threaded retaining rings of this type are standard hardware in compound and stereo microscopes, used to lock objective lenses, filters, or other optical elements into their housings. Bausch & Lomb has manufactured precision optical and microscopy equipment since the mid-1800s and was a dominant supplier of laboratory and research microscopes throughout the 20th century. Replacement and repair parts like this ring are sought by microscope technicians, optical instrument repair shops, university and hospital instrument maintenance departments, and collectors restoring vintage Bausch & Lomb instruments. The knurled grip and threaded collar design is common across many B&L microscope models and eras, making this type of part widely useful for maintenance and restoration work.