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Products HomeRetaining Rings
- Allow Easy Mounting of Optical Components
- Compatible with Our Line of Lens Tubes and Mounts
- Extra-Thick, Stress-Free, Delrin (Plastic), and Stainless Steel Versions
- M5.5 x 0.5 to SM4 Threading
CMRR
C-Mount (1.00"-32) Retaining Ring
SM05LTRR
SM05 (0.535"-40)
Stress-Free Retaining Ring
SM1PRR
SM1 (1.035"-40)
Plastic Retaining Ring
SM75RR
SM75 (M75.5 x 0.5)
Retaining Ring
SM4RR
SM4 (4.035"-40)
Retaining Ring
SM2RRC
SM2 (2.035"-40)
Extra-Thick Retaining Ring
POLARIS-SM1RR
SM1 (1.035"-40)
Stainless Steel Retaining Ring
Please Wait
Retaining Rings Selection Guidea
| Standard Retaining Rings: Ø5 mm to Ø1/2" |
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| Standard Retaining Rings: Ø13 mm to Ø1" |
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| Standard Retaining Rings: Ø30 mm to Ø1.5" |
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| Standard Retaining Rings: Ø39 mm to Ø2" |
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| Standard Retaining Rings: Ø75 mm to Ø4" |
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| Extra-Thick Retaining Rings |
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| Stress-Free Retaining Rings |
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| Plastic Retaining Rings |
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| Stainless Steel Retaining Rings |
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Features
- Standard (Aluminum) Retaining Rings Available for Optics Ranging from Ø5 mm to Ø4"
- Extra-Thick SM05-, SM1-, and SM2-Threaded Retaining Rings for High-Curvature Lenses
- Stress-Free Retaining Rings are Compatible with the SM05, SM1, and SM2 Thread Standards
- Delrin (Plastic) SM05- and SM1-Threaded Retaining Rings Provide Gentler Contact with Optic Surface
- Stainless Steel SM05-, SM1-, and SM2-Threaded Retaining Rings for Our SM-Threaded Polaris Mounts
- Standard Ø1/2", Ø1", and Ø2" Retaining Rings Available in Packs of 5 or 10
Thorlabs offers a wide selection of Retaining Rings for securing optical components into our threaded mounts, lens tubes, and unmounted optic adapters. Two retaining rings can be used to secure the optical component inside the center of a lens tube: one as a stopper and the other to lock in the component.
Depending on the size needed, these retaining rings are available in one or more of the following types: standard (aluminum), extra-thick, stress-free, plastic, or stainless steel. For a table of available options, please see the Retaining Rings Selection Guide to the right.
We offer extra-thick (5 mm) retaining rings which provide easier mounting for high-curvature lenses, such as aspheric lenses and condenser lenses (see the Lens Mounting Guide tab for more information). Our Stress-Free Retaining Rings (Item #'s SM05LTRR, SM1LTRR, and SM2LTRR) have a rubber O-ring that provides a light-tight seal around the optical components. The SM05PRR and SM1PRR Plastic Retaining Rings are produced from Delrin to provide gentler contact with an optic's surfaces than our standard retaining rings. Please keep in mind that due to the increased thickness of the stress-free and plastic retaining rings, the thickness of the optic that can be accommodated in the mount may be reduced. Finally, stainless steel retaining rings are ideal for use with our SM-threaded Polaris mirror mounts.
Thorlabs also offers a line of fixed-diameter and adjustable spanner wrenches for rings for optic diameters from 5 mm to 3" and spanner bits for SM05, SM1, SM2, and SM3 retaining rings. For using multiple thread types in the same setup, please see our extensive line of thread adapters.
For ordering convenience, the SM05RR and SM1RR Standard Retaining Rings are available in packs of 10, and the SM2RR Standard Retaining Ring is available in packs of 5.
Thorlabs' retaining rings are used to secure unmounted optics within lens tubes or optic mounts. These rings are secured in position using a compatible spanner wrench. For flat or low-curvature optics, standard retaining rings manufactured from anodized aluminum are available from Ø5 mm to Ø4". For high-curvature optics, extra-thick retaining rings are available in Ø1/2", Ø1", and Ø2" sizes.
Extra-thick retaining rings offer several features that aid in mounting high-curvature optics such as aspheric lenses, short-focal-length plano-convex lenses, and condenser lenses. As seen in the animation to the right, the guide flange of the spanner wrench will collide with the surface of high-curvature lenses when using a standard retaining ring, potentially scratching the optic. This contact also creates a gap between the spanner wrench and retaining ring, preventing the ring from tightening correctly. Extra-thick retaining rings provide the necessary clearance for the spanner wrench to secure the lens without coming into contact with the optic surface.
| Posted Comments: | |
chris
(posted 2017-06-12 08:51:23.777) Unclear what I need. Have 30mm unmounted optics and want to install in SM2 tube. What item do I need? Thanks. CHris tfrisch
(posted 2017-06-26 10:34:41.0) Hello, thank you for contacting Thorlabs. You may want to look at AD2-30 or SM2AD30 on our 2" adapters page:
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=5324 rachid
(posted 2017-05-03 22:29:46.17) I am planing to buy polarizer "LPVISE200-A" with a rotating mount "RSP2".
what kind of ring is suitable for me so I can hold the polarizer ?
Regards, Rachid tcampbell
(posted 2017-05-03 11:53:06.0) Response from Tim at Thorlabs: The RSP2 rotation mount has an SM2-threaded bore, which accepts SM2RR retaining rings. However, one SM2RR retaining ring is already included with the RSP2 mount to hold the optic against the mount's fixed retention lip. christoph.bohr
(posted 2016-11-03 10:35:46.07) Given the small torque used in tightening down the retaining rings I wonder if there is a recommended method for securing the retaining rings to keep them from working loose in a high vibration environment. Something like a thread locker but ideally something that still allows disassembly for service and does not interfere with the lens and coating material.
regards
C. Bohr tfrisch
(posted 2016-11-04 09:26:04.0) Hello, thank you for contacting Thorlabs. I will reach out to you directly to discuss your high vibration application. tmorgus
(posted 2016-06-10 16:34:03.81) Hello Cbrideau, Dito. This was a project that kept slipping to the back burner since there are alternative solutions. But it is nice to finally have the right solution available for highly curved optics. Sincerely, Tyler Mechanics Business Unit Leader cbrideau
(posted 2016-06-10 15:32:13.92) Glad to see these thick rings finally available! I'll be talking to my local distributor about getting some for holding large condenser lenses. cbrideau
(posted 2016-02-22 11:54:32.26) Would love to be able to get the extra-thick version of these for mounting Condenser lenses. These rings are used in your pre-built collimation mounts but thus far you don't sell them individually. schach
(posted 2014-08-13 14:01:20.563) Guten Tag,
welches Gewinde besitzt der Sicherungsring SM18RR?
In der Liste finde ich die Angabe M18,5x0,5, die dazugehörige Angabe in der Zeichnung lautet 0,750-40!
Vielen Dank im voraus.
Mit freundlichen Grüßen
C.Schach jlow
(posted 2014-08-13 08:48:36.0) Response from Jeremy at Thorlabs: Thank you for bringing this to our attention. The correct thread is 0.750"-40 for the SM18RR. We will correct the thread call out on the website. nick
(posted 2013-02-01 12:08:06.75) Can you please clarify what the o-ring material is (for product SM05LTRR), as well as its lifetime rating in an ambient environment? tcohen
(posted 2013-02-06 15:26:00.0) Response from Tim at Thorlabs: The O-Ring is Buna-N. We have updated our presentation to include this information. tcohen
(posted 2012-09-18 15:10:00.0) Response from Tim at Thorlabs to Luis: These have a black anodized finish which is typically not suitable for UHV. I will contact you directly to discuss your requirements and provide a quote for a vacuum compatible version. lgml1
(posted 2012-09-17 16:22:31.0) Hello, this is very useful.
I just wish to ask whether any the SM17RR is suitable for being used in ultra high vacuum (I'm designing a customised tuve for holding the lens).
Cheers,
Luis tcohen
(posted 2012-07-19 13:04:00.0) Response from Tim at Thorlabs: Thank you for contacting us. This will depend on the lens dimensions and material. Qualitatively, you want to use the minimum amount of torque required to secure the optic as overtightening will induce stress birefringence. That being said, the retaining rings should hold the optic in a much less stressful way at the point of contact than a setscrew for example. Stress-free retaining rings were designed with this in mind. I will contact you directly to continue this conversation. sebastien.avila
(posted 2012-07-17 10:38:21.0) Hello,
What is the tightening torque that should not be exeed while using an SM18RR on a 18mm diameter convex lens? We want to have a standar procedure to mounting these lenses and we need to stablish the maximum torque allowed.
Thank you. tcohen
(posted 2012-06-19 10:55:00.0) Response from Tim at Thorlabs: The external thread specifications for the M15.5-0.5 thread used on our SM15RR are Major Max 15.479, Major Min 15.371, Minor Max 14.938, Minor Min 14.757, Pitch Max 15.155 and Pitch Min 15.065. jbowen
(posted 2012-06-18 08:51:32.0) I would like to know the thread specification for this part. Please provide the minor, major, and pitch diameters with the minimum and maximum tolerances for each dimension. |
Zoom- Standard Retaining Rings for Optics Ranging
from Ø5 mm to Ø1/2" - Compatible with our Optic Mounts and Lens Tubes
- SM05RR Retaining Rings Available in 10 Packs
Our Standard Retaining Rings are manufactured from anodized aluminum and are offered in sizes to match our optic mounts and lens tubes. They maximize the clear aperture while providing sufficient holding force. Securing an optic using a retaining ring is a stable method for holding the optic since the optic is retained along its entire edge instead of just at a few points. Each retaining ring is machined with two slots for compatibility with our selection of spanner wrenches.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench | Compatible Optic Mounts | Clear Aperture |
|---|---|---|---|---|---|---|
| SM5RR | M5.5 x 0.5 | 0.07" (1.7 mm) |  |
SPW801 | LMR5(/M), AD5T, CPM05, SP07, or SM1AD5 |
Ø0.15" (Ø3.8 mm) |
| SM6RR | M6.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR6(/M), AD6T, CPM06, SP08, or SM1AD6 |
Ø0.19" (Ø4.8 mm) |
| SM7RR | M7.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR7(/M), AD7T, SP09, or SM1AD7 | Ø0.23" (Ø5.8 mm) |
| SM8RR | M8.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR8(/M), AD8T, CPM08, SP10, or SM1AD8 |
Ø0.27" (Ø6.9 mm) |
| SM9RR | M9.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR9(/M), AD9T, CPM09, SP11, or SM1AD9 |
Ø0.31" (Ø7.9 mm) |
| SM10RR | M10.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR10(/M), AD10T, SP12, or SM1AD10 | Ø0.35" (Ø8.8 mm) |
| SM11RR | M11.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | AD11T, SP13, or SM1AD11 | Ø0.36" (Ø9.1 mm) |
| SM12RR | M12.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | SP14 | Ø0.40" (Ø10.2 mm) |
| SM05RR(-P10) | SM05 (0.535"-40) | 0.07" (1.7 mm) | |
SPW603 or SPW801 | Any Internally SM05-Threaded Mount | Ø0.44" (Ø11.0 mm) |
Zoom- Standard Retaining Rings for Optics Ranging from Ø13 mm to Ø1"
- SM-Threaded Retaining Rings are Compatible with our SM Optic Mounts and Lens Tubes
- Retaining Rings with RMS (0.800"-36) and C-Mount (1.00"-32) Threads Available
- SM1RR Retaining Rings Available in 10 Packs
Our Standard Retaining Rings are manufactured from anodized aluminum and are offered in sizes to match our optic mounts and lens tubes. They maximize the clear aperture while providing sufficient holding force. Securing an optic using a retaining ring is a stable method for holding the optic since the optic is retained along its entire edge instead of just at a few points. Each retaining ring is machined with two slots for compatibility with our selection of spanner wrenches.
Our C-Mount-threaded (1.00"-32) retaining ring is ideal for securing optical components into our CMR lens mount or CP13 30 mm cage plate and C- or CS-Mount compatible CCD and CMOS cameras. As shown in the photo to the left, this retaining ring is engraved with both the part number and "C-Mount" to distinguish it from our SM-threaded retaining rings.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench | Compatible Optic Mounts | Clear Aperture |
|---|---|---|---|---|---|---|
| SM13RR | M13.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | AD13T or SM1AD13 | Ø0.43" (Ø10.9 mm) |
| SM14RR | M14.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | AD14T or SM1AD14 | Ø0.46" (Ø11.7 mm) |
| SM15RR | M15.5 x 0.5 | 0.07" (1.7 mm) | |
SPW801 | LMR15 (LMR15/M), AD15T, CPM15, or SM1AD15 |
Ø0.50" (Ø12.7 mm) |
| SM16RR | M16.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | AD16T or SM1AD16 | Ø0.54" (Ø13.6 mm) |
| SM17RR | M17.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | AD17T or SM1AD17 | Ø0.57" (Ø14.5 mm) |
| SM18RR | 0.750"-40 | 0.08" (2.0 mm) | |
SPW801 | LMR18 (LMR18/M), AD18T, CPM18, or SM1AD18 |
Ø0.62" (Ø15.7 mm) |
| SM19RR | M19.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | AD19T or SM1AD19 | Ø0.64" (Ø16.3 mm) |
| RMSRR | 0.800"-36 | 0.07" (2.0 mm) | |
SPW801 | HCS013 | Ø0.67" (Ø17.0 mm) |
| SM20RR | M20.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | LMR20 (LMR20/M), AD20T, CPM20, or SM1AD20 |
Ø0.68" (Ø17.3 mm) |
| CMRR | 1.00"-32 | 0.08" (2.0 mm) | |
SPW801 | CMR (CMR/M) or CP13 (CP13/M) |
Ø0.87" (Ø22.0 mm) |
| SM1RR(-P10) | SM1 (1.035"-40) | 0.08" (2.0 mm) | |
SPW606, SPW602, or SPW801 | Any Internally SM1-Threaded Mount | Ø0.90" (Ø22.9 mm) |
Zoom- Standard Retaining Rings for Optics Ranging
from Ø30 mm to Ø1.5" - Compatible with our Optic Mounts and Lens Tubes
Our Standard Retaining Rings are manufactured from anodized aluminum and are offered in sizes to match our optic mounts and lens tubes. They maximize the clear aperture while providing sufficient holding force. Securing an optic using a retaining ring is a stable method for holding the optic since the optic is retained along its entire edge instead of just at a few points. Each retaining ring is machined with two slots for compatibility with our selection of spanner wrenches.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench | Compatible Optic Mounts | Clear Aperture |
|---|---|---|---|---|---|---|
| SM30RR | SM30 (M30.5 x 0.5) | 0.08" (2.0 mm) | |
SPW607 or SPW801 | Any Internally SM30-Threaded Mount | Ø1.10" (Ø27.9 mm) |
| SM31RR | M31.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD31 | Ø1.14" (Ø29.0 mm) |
| SM32RR | M32.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD32 or C32 | Ø1.18" (Ø30.0 mm) |
| SM33RR | M33.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD33 | Ø1.22" (Ø31.0 mm) |
| SM34RR | M34.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD34 | Ø1.26" (Ø32.0 mm) |
| SM35RR | M35.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD35 | Ø1.30" (Ø33.0 mm) |
| SM36RR | M36.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD36 | Ø1.34" (Ø34.0 mm) |
| SM37RR | M37.5 x 0.5 | 0.08" (2.0 mm) | |
SPW801 | SM2AD37 | Ø1.38" (Ø35.0 mm) |
| SM38RR | M38 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2A20 or WFA4111 |
Ø1.38" (Ø34.9 mm) |
| SM1.5RR | SM1.5 (1.535"-40) | 0.10" (2.5 mm) | |
SPW801 | LMR1.5 (LMR1.5/M) or SM2AD1.5 | Ø1.37" (Ø34.8 mm) |
Zoom- Standard Retaining Rings for Optics Ranging
from Ø39 mm to Ø2" - Compatible with our Optic Mounts and Lens Tubes
- SM2RR Retaining Rings Available in 5 Packs
Our Standard Retaining Rings are manufactured from anodized aluminum and are offered in sizes to match our optic mounts and lens tubes. They maximize the clear aperture while providing sufficient holding force. Securing an optic using a retaining ring is a stable method for holding the optic since the optic is retained along its entire edge instead of just at a few points. Each retaining ring is machined with two slots for compatibility with our selection of spanner wrenches.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench | Compatible Optic Mounts | Clear Aperture |
|---|---|---|---|---|---|---|
| SM39RR | M39.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD39 | Ø1.44" (Ø36.5 mm) |
| SM40RR | M40.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD40 | Ø1.47" (Ø37.5 mm) |
| SM41RR | M41.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD41 | Ø1.51" (Ø38.5 mm) |
| SM42RR | M42.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD42 | Ø1.55" (Ø39.5 mm) |
| SM43RR | M43.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD43 | Ø1.59" (Ø40.5 mm) |
| SM44RR | M44.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD44 | Ø1.63" (Ø41.5 mm) |
| SM45RR | M45.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | LMR45 (LMR45/M) or SM2AD45 | Ø1.67" (Ø42.4 mm) |
| SM46RR | M46.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD46 | Ø1.71" (Ø43.5 mm) |
| SM47RR | M47.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD47 | Ø1.75" (Ø44.5 mm) |
| SM48RR | M48.5 x 0.5 | 0.10" (2.5 mm) | |
SPW801 | SM2AD48 | Ø1.79" (Ø45.5 mm) |
| SM2RR(-P5) | SM2 (2.035"-40) | 0.10" (2.5 mm) | |
SPW604 or SPW801 | Any Internally SM2-Threaded Mount | Ø1.90" (Ø48.3 mm) |
Zoom- Standard Retaining Rings for Optics Ranging
from Ø75 mm to Ø4" - Compatible with our Optic Mounts and Lens Tubes
Our Standard Retaining Rings are manufactured from anodized aluminum and are offered in sizes to match our optic mounts and lens tubes, are designed to maximize the clear aperture while providing sufficient holding force. Securing an optic using a retaining ring is a stable method for holding the optic since the optic is retained along its entire edge instead of just at a few points. Each retaining ring is machined with two slots for compatibility with our selection of spanner wrenches.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench | Compatible Optic Mounts | Clear Aperture |
|---|---|---|---|---|---|---|
| SM75RR | M75.5 x 0.5 | 0.16" (4.1 mm) | |
SPW801a | LMR75 (LMR75/M) | Ø2.81" (Ø71.4 mm) |
| SM3RR | SM3 (3.035"-40) | 0.10" (2.5 mm) | |
SPW605 or SPW801a | Any Internally SM3-Threaded Mount | Ø2.81" (Ø71.4 mm) |
| SM100RR | M100.75 x 0.5 | 0.16" (4.1 mm) | |
N/A | LMR100 (LMR100/M) | Ø3.80" (Ø96.4 mm) |
| SM4RR | SM4 (4.035"-40) | 0.13" (3.3 mm) | |
N/A | LMR4 (LMR4/M) | Ø3.81" (Ø96.8 mm) |
Zoom- Extra-Thick (5 mm) SM05-, SM1-, and SM2-Threaded Retaining Rings
- Ideal for Use With High-Curvature Lenses Such as Aspheric Lenses and Condenser Lenses (See the Lens Mounting Guide Tab Above for More Information)
These extra-thick SM05, SM1, and SM2 retaining rings are manufactured from anodized aluminum and are designed with a 5 mm thickness for easier mounting of high-curvature lenses, such as aspheric lenses and condenser lenses. The SM threading on the outside of the ring does not extend down the entire thickness of the ring. For best performance, the retaining ring should be used with the non-threaded side contacting the lens. Please see the table below for a list of compatible spanner wrenches.
| Item # | Thread | Thicknessa | Thread Specs | Compatible Spanner Wrench |
Compatible Optic Mounts |
Clear Aperture |
|---|---|---|---|---|---|---|
| SM05RRC | SM05 (0.535"-40) | 0.20" (5.0 mm) | |
SPW603 or SPW801 | Any Internally SM05-Threaded Mount | Ø0.44" (Ø11.0 mm) |
| SM1RRC | SM1 (1.035"-40) | 0.20" (5.0 mm) | |
SPW606, SPW602, or SPW801 | Any Internally SM1-Threaded Mount | Ø0.90" (Ø22.9 mm) |
| SM2RRC | SM2 (2.035"-40) | 0.20" (5.0 mm) | |
SPW604 or SPW801 | Any Internally SM2-Threaded Mount | Ø1.90" (Ø48.3 mm) |
Zoom| Stress-Free Retaining Ring |
Clear Aperture | Standard Retaining Ring |
Clear Aperture |
|---|---|---|---|
| SM05LTRR | Ø0.32" (Ø8.1 mm) | SM05RR | Ø0.44" (Ø11.0 mm) |
| SM1LTRR | Ø0.82" (Ø20.8 mm) | SM1RR | Ø0.90" (Ø22.9 mm) |
| SM2LTRR | Ø1.68" (Ø42.7 mm) | SM2RR | Ø1.90" (Ø48.3 mm) |
- Design Provides Reduced Stress Clamping Action
- Provides Light-Tight Seal Around an Optic
- Compatible with our Optic Mounts and Lens Tubes
Our Stress-Free Retaining Rings are available with our standard SM05, SM1, or SM2 threadings. This design uses an O-ring made of Buna-N nitrile rubber to reduce the stress on the optic surface and completely seal out sources of stray light. Like our standard retaining rings, our stress-free retaining rings contain two slots for compatibility with our selection of spanner wrenches.
Due to the rubber O-ring, the clear aperture is slightly reduced relative to our standard retaining rings. Please see the table to the upper right for details.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench |
Compatible Optic Mounts |
|---|---|---|---|---|---|
| SM05LTRR | SM05 (0.535"-40) | 0.15" (3.8 mm) | |
SPW603 or SPW801 | Any Internally SM05-Threaded Mount |
| SM1LTRR | SM1 (1.035"-40) | 0.16" (4.1 mm) | |
SPW602 or SPW801 | Any Internally SM1-Threaded Mount |
| SM2LTRR | SM2 (2.035"-40) | 0.18" (4.6 mm) | |
SPW604 or SPW801 | Any Internally SM2-Threaded Mount |
Zoom| Plastic Retaining Ring |
Clear Aperture | Standard Retaining Ring |
Clear Aperture |
|---|---|---|---|
| SM05PRR | Ø0.44" (Ø11.0 mm) | SM05RR | Ø0.44" (Ø11.0 mm) |
| SM1PRR | Ø0.80" (Ø20.3 mm) | SM1RR | Ø0.90" (Ø22.9 mm) |
- Provide Gentler Contact with an Optic's Surfaces than Standard Retaining Rings
- Compatible with our Optic Mounts and Lens Tubes
The SM05PRR and SM1PRR Delrin (Plastic) Retaining Rings provide gentler contact with the surface of optics than our standard retaining rings. They are compatible with any internally SM05- or SM1-threaded optic mount, respectively.
Each of these plastic retaining rings is thicker than the standard retaining ring of the same diameter featured above. Please note that due to the increased thickness, the maximum optic thickness that can be accommodated inside our standard SM05- and SM1-compatible mounts will be slightly diminished. In addition, the clear aperture of SM1PRR plastic retaining ring is slightly reduced compared to its standard counterpart.
Refer to the table below for compatible spanner wrench options, and see the table to the upper right for the diameter of each plastic retaining ring relative to our standard retaining rings.
Zoom| Stainless Steel Retaining Ring |
Clear Aperture | Standard Retaining Ring |
Clear Aperture |
|---|---|---|---|
| POLARIS-SM05RR | Ø0.43" (Ø10.9 mm) | SM05RR | Ø0.44" (Ø11.0 mm) |
| POLARIS-SM1RR | Ø0.90" (Ø22.9 mm) | SM1RR | Ø0.90" (Ø22.9 mm) |
| POLARIS-SM2RR | Ø1.90" (Ø48.3 mm) | SM2RR | Ø1.90" (Ø48.3 mm) |
- SM05-, SM1-, and SM2-Threaded Stainless Steel Retaining Rings
- Ideal for Use With Our SM-Threaded Polaris Mirror Mounts
These stainless steel SM05, SM1, and SM2 retaining rings have identical thread specifications when compared to our standard SM05 (item # SM05RR), SM1 (item # SM1RR), and SM2 (item # SM2RR) retaining rings. They are designed for use with our SM-threaded Polaris mirror mounts. The matched material (stainless steel) helps reduce thermal hysteresis by having a matched coefficient of thermal expansion (CTE) to the Polaris mount. Please refer to the table below for compatible spanner wrench options, and see the table to the upper right for the diameter of each stainless steel retaining ring relative to our standard retaining rings.
| Item # | Thread | Thickness | Thread Specs | Compatible Spanner Wrench |
Compatible Optic Mounts |
|---|---|---|---|---|---|
| POLARIS-SM05RR | SM05 (0.535"-40) | 0.07" (1.7 mm) | |
SPW603 or SPW801 | Any Internally SM05-Threaded Mount |
| POLARIS-SM1RR | SM1 (1.035"-40) | 0.08" (2.0 mm) | |
SPW606, SPW602, or SPW801 | Any Internally SM1-Threaded Mount |
| POLARIS-SM2RR | SM2 (2.035"-40) | 0.10" (2.5 mm) | |
SPW604 or SPW801 | Any Internally SM2-Threaded Mount |
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