Adjustable SM05 Lens Tubes

  • Rotating Adjustment of Ø1/2" Optics
  • 0.31" (7.9 mm) or 0.81" (20.6 mm) Adjustment Range
  • SM05 (0.535"-40) Threading
  • Max Optic Thickness: 0.43" (11.0 mm)

A lens housed in an SM05V05 that is threaded into an SM05L15 lens tube is used to focus light onto the detector.


Ø1/2" Adjustable Lens Tube,
0.31" Travel Range


Ø1/2" Adjustable Lens Tube
0.81" Travel Range


Ø1/2" Vacuum-Compatible Adjustable Lens Tube,
0.31" Travel Range

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SM05V05 Adjustable Lens Tube Mechanical Drawing
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Amin and Amax are the minimum and maximum distances another lens tube can be positioned from the back of the lens cell when using the locking ring.


  • Long Externally-Threaded Section for Adjustable Positioning of Mounted Optics
  • Available Adjustment Ranges: 0.31" (7.9 mm) or 0.81" (20.6 mm)
  • Holds Ø1/2" (Ø12.7 mm) Optics
  • Maximum Optic Thickness of 0.43" (11.0 mm)
  • One Retaining Ring and Locking Ring Included
  • Vacuum-Compatible Version with 0.31" (7.9 mm) Adjustment Range

These SM05-threaded (0.535"-40) adjustable lens tubes allow Ø1/2" optics to be precisely positioned along the optical axis of a lens tube system. To operate, mount the optic in the adjustable-length lens tube using the included retaining ring. Then thread the adjustable lens tube into a compatible SM05-threaded lens tube or lens mount until the optic is at the desired position. At this point, the included locking ring can be used to fix the position of the lens tube. These rotating adjustable lens tubes are an ideal solution for fine tuning of the first and last lenses in a lens tube system. Although a lens tube can be attached to the front of the adjustable lens tube, it should only be done after the position of the optic has been fixed since this lens tube will need to be free to rotate and translate if the position of the optic is changed.

The SM05V05 and SM05V10 adjustable lens tubes include one SM05RR retaining ring and one SM05NT locking ring. For applications where it is difficult to reach the locking ring by hand, we offer the SM05NT1 Slotted Locking Ring and SPW502 Spanner Wrench. This locking ring contains slots for the 3/4" end of the spanner wrench.

The SM05V05V adjustable lens tube is a vacuum-compatible version of the SM05V05 lens tube with the addition of vented channels along its threading and at the ends the tube. These channels allow air trapped between mounted optics an easy means of escape during pumpdown. The lens tube comes with an SM05RRV retaining ring and SM05NT1V locking ring. All components are made from 6061-T6 aluminum, allowing this adjustable lens tube to be vacuum compatible down to 10-6 Torr.

Item # External Thread Length (L) Adjustment Range (Amin to Amax)a
SM05V05(V) 0.5" (12.7 mm) 0.11" - 0.42" (2.8 mm - 10.7 mm)
SM05V10 1.0" (25.4 mm) 0.11" - 0.92" (2.8 mm - 23.4 mm)
  • Amin includes the thickness of the included locking ring, while Amax accounts for the minimum 0.08" (2 mm) thread depth needed to engage the attached lens tube or component.
Alternatives Ø1", Ø1.5"Ø2", and Ø3" Adjustable Lens Tubes

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"

Posted Comments:
user  (posted 2019-12-05 12:56:34.167)
Does the adjustable lens tube allow rotation of the optic independent of translation? The 2D hatched section view looks like it might, but the 3D CAD model does not, showing it as a single body.
llamb  (posted 2019-12-06 01:35:42.0)
Thank you for your feedback. Besides the included locking nut and retaining ring, the SM05V05 is a single body. The tube itself will not rotate the optic without translation.
stepan.vyhlidka  (posted 2018-06-29 09:41:49.213)
Hello, the locking ring SM05NT does not fit in between 16 mm cage construction rods (it cannot be rotated then - locked/unlocked). We bough one to tune the position of the lens to collimate the fiber within cage assembly. Could you decrease its diameter?
YLohia  (posted 2018-07-03 10:14:36.0)
Hello, thank you for your feedback. I have posted this idea in our internal engineering forum. Reducing the diameter would indeed make this compatible with the 16mm cage system.
cpv  (posted 2017-11-27 16:23:27.433)
How can I couple this SM05V10 to a c-female thread? In other words, I would like a c-mount coupler to my 1/2'' lens. What can you offer? Best Regards, César
nbayconich  (posted 2017-12-04 11:31:50.0)
Thank you for contacting Thorlabs. We have a C-mount to SM05 adapter part number SM05A1 which can adapt the SM05V10 to a c-mount threaded camera using another SM05 lens tube. More information about our thread adapters can be found in the link below.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
SM05V05 Support Documentation
SM05V05 Ø1/2" Adjustable Lens Tube, 0.31" Travel
Lead Time
SM05V05V Support Documentation
SM05V05VVacuum-Compatible Ø1/2" Adjustable Lens Tube, 0.31" Travel
SM05V10 Support Documentation
SM05V10Ø1/2" Adjustable Lens Tube, 0.81" Travel