DescriptionProduct DescriptionSM2 (2.035”-40) internal threads for Ø2-inch optical components or lens sleeves.M4 threaded mounting holes at the bottom for installing Oeabt series rods.The SM-R2 series fixed mounts feature SM2 (2.035”-40) internal threads, designed for mounting Ø2-inch optical components or externally threaded lens sleeves. The M4 threaded holes at the bottom facilitate installation onto Ø12mm stainless steel rods for free-space applications.ModelSM-R2SM-R2ADimensions55.9*12.7*62.5mm55.9*12.7*62.5mmCentral ApertureSM2 (2.035”-40) partial threadsSM2 (2.035”-40) full threadsThread TypeM4M4Weight18.3g19.1gMaterial7075 aluminum alloy7075 aluminum alloyTechnical DescriptionOptical Knowledge Point: Common Optical Thread Size StandardsThis is a thread specific to Thorlabs Inc. (USA) and not a commonly used optical thread. “SM” is the code for sewing machine threads in thread notation, but this American company uses it for internal and external thread connections of optical lenses and sleeves. The thread type is UNS (Unified National Special Thread) with a tolerance class of 2A/2B. A unique feature of this thread is that regardless of the diameter, the pitch is 40 threads per inch (TPI). Specific dimensions are as follows:SeriesTypeThread (in)Nominal Diameter (mm)Minor Diameter (mm)Pitch Diameter (mm)Major Diameter (mm)SM05Internal0.535-4013.5912.98±0.0713.24±0.05＞13.59SM05External0.535-4013.59＜12.7813.10±0.0513.50±0.05SM1Internal1.535-4026.2925.68±0.0725.95±0.05＞26.29SM1External1.535-4026.29＜25.4825.79±0.0526.19±0.06SM2Internal2.535-4051.6951.08±0.07551.35±0.075＞51.69SM2External2.535-4051.69＜50.8751.18±0.0551.59±0.05Product DescriptionThe SM-R2 series fixed mounts feature SM2 (2.035”-40) internal threads, designed for mounting Ø2-inch optical components or externally threaded lens sleeves. The mounts are available in full-thread and partial-thread versions, with included retaining rings for fixing optical components.The SM-R2 has SM2 (2.035”-40) partial threads and can mount optical components up to 9.5mm thick. The SM-R2A has SM2 (2.035”-40) full threads and can mount optical components up to 9.0mm thickThe M4 threaded holes at the bottom facilitate installation onto Ø12mm stainless steel rods for free-space applications. We also offer the SM-R1 Ø1-inch fixed mount as an alternative.AssemblyApplication ExampleEngineering Drawing DownloadSM-R2A-Engineering DrawingSM-R2-Engineering Drawing
