Features
- Lever or Ring Aperture Control
- SM3 (3.035"-40) Internally and Externally Threaded
- Minimum Aperture: Ø2 mm (Ø0.08")
- Maximum Aperture: Ø50 mm (Ø1.97")
Our SM3 (3.035"-40) threaded irises are compatible with our Ø3" lens tubes and other SM3-threaded components. Each iris has internal SM threading on one side and external SM threading on the other side. The individual black spring steel leaves pivot within the outer ring of the iris and are designed for long-lasting performance over several thousand cycles.
The SM3D50D ring-actuated iris is designed for integration into confined setups, where the movement of a lever-actuated iris might be obstructed by other components. This iris also features a locking setscrew with a 0.05" (1.3 mm) hex for locking the ring during installation or removal.
Thorlabs' Threading Specifications
Thorlabs' lens tubes utilize a series of non-standard threadings. Threading specifications are given below for our SM threadings utilized in our lens tube and cage system components so that you can machine mating components to suit your application. We also offer products with C-Mount and RMS threadings, and the specifications for these threadings are also given below. Please note that other manufacturers may have different tolerances for these threads. For other thread specifications that are not listed here, please contact Tech Support.
SM05 Threading: Ø1/2" Lens Tubes, 16 mm Cage Systems |
External Thread, 0.535"-40.0, UNS-2A |
Internal Thread, 0.535"-40.0, UNS-2B |
Max Major Diameter |
0.5340" |
Min Major Diameter |
0.5350" |
Min Major Diameter |
0.5289" |
Min Pitch Diameter |
0.5188" |
Max Pitch Diameter |
0.5178" |
Max Pitch Diameter |
0.5230" |
Min Pitch Diameter |
0.5146" |
Min Minor Diameter (and 83.3% of thread) |
0.508" |
Max Minor Diameter |
0.5069" |
Max Minor Diameter (and 64.9% of thread) |
0.514" |
RMS Threading: Objective, Scan, and Tube Lenses |
External Thread, 0.800"-36.0, UNS-2A |
Internal Thread, 0.800"-36.0, UNS-2B |
Max Major Diameter |
0.7989" |
Min Major Diameter |
0.8000" |
Min Major Diameter |
0.7934" |
Min Pitch Diameter |
0.7820" |
Max Pitch Diameter |
0.7809" |
Max Pitch Diameter |
0.7866" |
Min Pitch Diameter |
0.7774" |
Min Minor Diameter (and 83.3% of thread) |
0.770" |
Max Minor Diameter |
0.7688" |
Max Minor Diameter (and 64.9% of thread) |
0.777" |
C-Mount Threading: Machine Vision Lenses, CCD/CMOS Cameras |
External Thread, 1.000"-32.0, UN-2A |
Internal Thread, 1.000"-32.0, UN-2B |
Max Major Diameter |
0.9989" |
Min Major Diameter |
1.0000" |
Min Major Diameter |
0.9929" |
Min Pitch Diameter |
0.9797" |
Max Pitch Diameter |
0.9786" |
Max Pitch Diameter |
0.9846" |
Min Pitch Diameter |
0.9748" |
Min Minor Diameter (and 83.3% of thread) |
0.966" |
Max Minor Diameter |
0.9651" |
Max Minor Diameter (and 64.9% of thread) |
0.974" |
SM1 Threading: Ø1" Lens Tubes, 30 mm Cage Systems |
External Thread, 1.035"-40.0, UNS-2A |
Internal Thread, 1.035"-40.0, UNS-2B |
Max Major Diameter |
1.0339" |
Min Major Diameter |
1.0350" |
Min Major Diameter |
1.0288" |
Min Pitch Diameter |
1.0188" |
Max Pitch Diameter |
1.0177" |
Max Pitch Diameter |
1.0234" |
Min Pitch Diameter |
1.0142" |
Min Minor Diameter (and 83.3% of thread) |
1.008" |
Max Minor Diameter |
1.0068" |
Max Minor Diameter (and 64.9% of thread) |
1.014" |
SM30 Threading: Ø30 mm Lens Tubes |
External Thread, M30.5x0.5 |
Internal Thread, M30.5x0.5 |
Max Major Diameter |
30.480 mm |
Min Major Diameter |
30.500 mm |
Min Major Diameter |
30.371 mm |
Min Pitch Diameter |
30.175 mm |
Max Pitch Diameter |
30.155 mm |
Max Pitch Diameter |
30.302 mm |
Min Pitch Diameter |
30.059 mm |
Min Minor Diameter (and 83.3% of thread) |
29.959 mm |
Max Minor Diameter |
29.938 mm |
Max Minor Diameter (and 64.9% of thread) |
30.094 mm |
SM1.5 Threading: Ø1.5" Lens Tubes |
External Thread, 1.535"-40, UNS-2A |
Internal Thread, 1.535"-40, UNS-2B |
Max Major Diameter |
1.5339" |
Min Major Diameter |
1.535" |
Min Major Diameter |
1.5288" |
Min Pitch Diameter |
1.5188" |
Max Pitch Diameter |
1.5177" |
Max Pitch Diameter |
1.5236" |
Min Pitch Diameter |
1.5140" |
Min Minor Diameter (and 83.3% of thread) |
1.508" |
Max Minor Diameter |
1.5068" |
Max Minor Diameter (and 64.9% of thread) |
1.514" |
SM2 Threading: Ø2" Lens Tubes, 60 mm Cage Systems |
External Thread, 2.035"-40.0, UNS-2A |
Internal Thread, 2.035"-40.0, UNS-2B |
Max Major Diameter |
2.0338" |
Min Major Diameter |
2.0350" |
Min Major Diameter |
2.0287" |
Min Pitch Diameter |
2.0188" |
Max Pitch Diameter |
2.0176" |
Max Pitch Diameter |
2.0239" |
Min Pitch Diameter |
2.0137" |
Min Minor Diameter (and 83.3% of thread) |
2.008" |
Max Minor Diameter |
2.0067" |
Max Minor Diameter (and 64.9% of thread) |
2.014" |
SM3 Threading: Ø3" Lens Tubes |
External Thread, 3.035"-40.0, UNS-2A |
Internal Thread, 3.035"-40.0, UNS-2B |
Max Major Diameter |
3.0337" |
Min Major Diameter |
3.0350" |
Min Major Diameter |
3.0286" |
Min Pitch Diameter |
3.0188" |
Max Pitch Diameter |
3.0175" |
Max Pitch Diameter |
3.0242" |
Min Pitch Diameter |
3.0133" |
Min Minor Diameter (and 83.3% of thread) |
3.008" |
Max Minor Diameter |
3.0066" |
Max Minor Diameter (and 64.9% of thread) |
3.014" |
SM4 Threading: Ø4" Fixed Lens Mounts |
External Thread, 4.035"-40.0, UNS-2A |
Internal Thread, 4.035"-40.0, UNS-2B |
Max Major Diameter |
4.0337" |
Min Major Diameter |
4.0350" |
Min Major Diameter |
4.0286" |
Min Pitch Diameter |
4.0188" |
Max Pitch Diameter |
4.0175" |
Max Pitch Diameter |
4.0245" |
Min Pitch Diameter |
4.0131" |
Min Minor Diameter (and 83.3% of thread) |
4.008" |
Max Minor Diameter |
4.0066" |
Max Minor Diameter (and 64.9% of thread) |
4.014" |