RR-SM Threaded Retaining Rings

The RR-SM family consists of two-slot externally threaded retaining rings, identified as aluminum alloy in the source. These accessories support selection of an axial retention arrangement for an optical assembly. Each of the six online models has a dedicated photograph specifying its inch thread notation, inside diameter and thickness. The documentation treats the SM05 through SM4 interfaces and bores separately: thread diameter, clear opening and supported optic diameter are not interchangeable. Thickness varies among 2, 2.5 and 3.3 mm rather than following one generic family value. The two slots provide installation-tool engagement, but a tool is not stated to be included. Thread fit, engagement length, optic-edge contact and preload still require confirmation for the actual lens tube. English artwork identifies the annular external-thread and two-slot design; it is not a dimensioned drawing or a promise of supplied accessories.

Externally threaded, two-slot design

RR-SM is a family of thin black annular retaining rings with external threads. The main source photograph explicitly identifies aluminum alloy and two slots for installation and removal. The part is a continuous open-center ring, not a split spring circlip. The slots provide tool engagement, but an installation tool, optic and lens tube are not assumed to be included. Slot width, slot depth, tool designation and tightening torque are unspecified.

Six separate thread selections

The dedicated photographs identify SM05, SM1, SM1.5, SM2, SM3 and SM4 external threads, labeled 0.535 inch–40, 1.035 inch–40, 1.535 inch–40, 2.035 inch–40, 3.035 inch–40 and 4.035 inch–40 respectively. The original inch thread markings are retained. Selection names such as SM1.0 do not supply additional dimensions or a thread class absent from the source.

Model-specific bore and thickness

Inside diameters for the six models are 11, 22.9, 34.9, 48.3, 71.4 and 96.8 mm respectively. Their thicknesses are 2, 2, 2.5, 2.5, 2.5 and 3.3 mm. These are values explicitly labeled in the dedicated images, not nominal optic diameters or a uniform family thickness. Clear opening and edge contact also depend on the lens tube and optic. The bore dimension alone does not establish a verified assembly fit.

Material, assembly and supply checks

The source identifies aluminum alloy but supplies no alloy grade, surface-treatment specification, thread tolerance or mechanical rating. Black appearance does not establish certified anodizing. Before assembly, check the mating internal thread’s full specification, engagement length, optic edge, axial clearance and required preload. Do not infer fit from model digits. Confirm supplied quantity, tools, protective washers, stock and actual delivery separately.

Selection checklist

Match the full RR-SM model to the mating internal thread

Check bore, thickness and contact with the optic edge

Confirm slot dimensions, tool engagement and allowable preload

Confirm alloy grade, finish, quantity and actual delivery

To be confirmed

Thread class, tolerances, engagement length and slot dimensions

Aluminum-alloy grade, surface treatment and torque limits

Supported optic dimensions and verified assembly fit

Quantity, tools, washers, stock and actual delivery