
This page features Thorlabs' numerous options for mounting lenses in fixed mounts. Traditional fixed optic mounts (LMR series) are available for 13 discrete optic diameters ranging from Ø1/2" to Ø4", feature internal threading, and come complete with one retaining ring for securing the optic in place. Alternatively, if your application could benefit from a mount that has both internal an external SM threads, choose a member of our LMRxxS series. In either case, the fixed mount features an 8-32 (M4) tapped hole for post mounting. For small optics (i.e., less than Ø10 mm), we offer stainless steel adapters that allow these optics to be mounted in either our SM05-threaded or SM18-threaded mounts. We also offer a line of small optic adapters with external SM1 threading, which can mount optics from Ø5 mm to Ø20 mm in SM1-threaded lens mounts.


| Item # | Optic Diameter | Max Optic Thickness* | Clear Aperture | Optical Height | Included Retaining Ring | Spanner Wrench |
|---|---|---|---|---|---|---|
| LMR05 (/M) | Ø1/2" | 0.21" (5 mm) | Ø0.43" (Ø10.9 mm) | 0.63" (16.0 mm) | SM05RR | SPW603 |
| LMR15 (/M) | Ø15 mm | 0.30" (7.7 mm) | Ø0.50" (Ø12.7 mm) | 0.70" (17.8 mm) | SM15RR | SPW801 |
| LMR18 (/M) | Ø18 mm | 0.29" (7.4 mm) | Ø0.61" (Ø15.5 mm) | 0.75" (19.1 mm) | SM18RR | SPW801 |
| LMR20 (/M) | Ø20 mm | 0.29" (7.4 mm) | Ø0.68" (Ø17.3 mm) | 0.82" (20.8 mm) | SM20RR | SPW801 |
*This specification is true for thin lenses. For lenses with small focal lengths, and hence large lens curvatures, please contact technical support to ensure a proper fit.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMR05 |
Imperial Lens Mount for Ø1/2" Optics |
$14.30 |
Today |
LMR15 |
Lens Mount for Ø15 mm Optics, One Retaining Ring Included |
$20.00 |
Today |
LMR18 |
Imperial Lens Mounting Ring for 18mm Optics |
$22.00 |
Today |
LMR20 |
Lens Mount for Ø20 mm Optics, One Retaining Ring Included |
$24.00 |
Today |
LMR05/M |
Metric Lens Mount For 0.5" Optics |
$14.30 |
Today |
LMR15/M |
Metric, Lens Mount for Ø15 mm Optics, One Retaining Ring Included |
$20.00 |
Today |
LMR18/M |
Metric Lens mounting ring for 18 mm Optics |
$22.00 |
Today |
LMR20/M |
Metric, Lens Mount for Ø20 mm Optics, One Retaining Ring Included |
$24.00 |
Today |
| Item # | Optic Diameter | Max Optic Thickness* | Clear Aperture | Optical Height | Included Retaining Ring | Spanner Wrench |
|---|---|---|---|---|---|---|
| LMR1 (/M) | Ø1" | 0.28" (7.1 mm) | Ø0.90" (Ø23.0mm) | 0.87" (22.1 mm) | SM1RR | SPW602 |
| LMR30 (/M) | Ø30 mm | 0.28" (7.1 mm) | Ø1.10" (Ø28.0 mm) | 1.00" (25.4 mm) | SM30RR | SPW801 |
| LMR1.5 (/M) | Ø1.5" | 0.36" (9.1 mm) | Ø1.40" (Ø35.6 mm) | 1.13" (28.7 mm) | SM1.5RR | SPW801 |
| LMR45 (/M) | Ø45 mm | 0.36" (9.2 mm) | Ø1.67" (Ø42.4 mm) | 1.30" (33.0 mm) | SM45RR | SPW801 |
*This specification is true for thin lenses. For lenses with small focal lengths, and hence large lens curvatures, please contact technical support to ensure a proper fit.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMR1 |
Imperial Lens Mount For 1" Optics |
$15.70 |
Today |
LMR30 |
Imperial Lens Mounting Ring for 30 mm Optics |
$26.50 |
Today |
LMR1.5 |
Imperial Lens Mount For 1.5" Optics |
$22.40 |
Today |
LMR45 |
Lens Mount for Ø45 mm Optics, One Retaining Ring Included |
$30.00 |
Today |
LMR1/M |
Metric Lens Mount For 1" Optics |
$15.70 |
Today |
LMR30/M |
Metric Lens mounting ring for 30 mm Optics |
$26.50 |
Today |
LMR1.5/M |
Metric Lens Mount For 1.5" Optics |
$22.40 |
Today |
LMR45/M |
Metric, Lens Mount for Ø45 mm Optics, One Retaining Ring Included |
$30.00 |
Today |
| Item # | Optic Diameter | Max Optic Thickness* | Clear Aperture | Optical Height | Included Retaining Ring | Spanner Wrench |
|---|---|---|---|---|---|---|
| LMR2 (/M) | Ø2" | 0.36" (9.1 mm) | Ø1.90" (Ø48.5 mm) | 1.35" (34.3 mm) | SM2RR | SPW604 |
| LMR75 (/M) | Ø75 mm | 0.30" (7.6 mm) | Ø2.81" (Ø71.4 mm) | 2.00" (50.8 mm) | SM75RR | SPW801 |
| LMR3 (/M) | Ø3" | 0.36" (9.2 mm) | Ø2.81" (Ø71.4 mm) | 2.00" (50.8 mm) | SM3RR | SPW605 |
| LMR100 (/M) | Ø100 mm | 0.54" (13.7 mm) | Ø3.80" (Ø96.4 mm) | 3.00" (76.2 mm) | SM100RR | |
| LMR4 (/M) | Ø4" | 0.54" (13.7 mm) | Ø3.81" (Ø96.8 mm) | 3.00" (76.2 mm) | SM4RR |
*This specification is true for thin lenses. For lenses with small focal lengths, and hence large lens curvatures, please contact technical support to ensure a proper fit.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMR2 |
Imperial Lens Mount For 2" Optics |
$23.50 |
Today |
LMR75 |
Imperial Lens mounting ring for 75 mm Optics |
$49.00 |
Today |
LMR3 |
Customer Inspired!Lens Mount for Ø3" Optics, One Retaining Ring Included |
$49.00 |
Today |
LMR100 |
Lens Mount for Ø100 mm Optics, One Retaining Ring Included |
$60.00 |
Today |
LMR4 |
Customer Inspired!Lens Mount for Ø4" Optics, One Retaining Ring Included |
$60.00 |
Today |
LMR2/M |
Metric Lens Mount For 2" Optics |
$23.50 |
Today |
LMR75/M |
Metric Lens mounting ring for 75 mm Optics |
$49.00 |
Today |
LMR3/M |
Customer Inspired!Metric, Lens Mount for Ø3" Optics, One Retaining Ring Included |
$49.00 |
Today |
LMR100/M |
Metric, Lens Mount for Ø100 mm Optics, One Retaining Ring Included |
$60.00 |
Today |
LMR4/M |
Customer Inspired!Metric, Lens Mount for Ø4" Optics, One Retaining Ring Included |
$60.00 |
Today |
These fixed lens mounts, which feature internal SM threading on one side and external SM threading on the other, are available for Ø1/2", Ø1", and Ø2" optics. The optic is secured in the mount with the included retaining ring and can be post mounted to a TR-Series Post.
The internal threading is deep enough to hold most unmounted optics, while the external threading is just deep enough to allow for the mounting of lens tubes, irises, or other internally threaded SM components (see picture to the right). Although the functionality of this part can be duplicated by combining two other Thorlabs parts, a lens tube slip ring and a lens tube, these fixed mounts offer significant price reduction, increased convenience, and smaller package size.
| Item # | Optic Diameter | Max Optic Thickness* | Clear Aperture | Optical Height | Included Retaining Ring | Spanner Wrench |
|---|---|---|---|---|---|---|
| LMR05S (/M) | Ø1/2" | 0.21" (5 mm) | Ø0.43" (Ø10.9 mm) | 0.63" (16.0 mm) | SM05RR | SPW603 |
| LMR1S (/M) | Ø1" | 0.28" (7.1 mm) | Ø0.90" (Ø23.0 mm) | 0.87" (22.1 mm) | SM1RR | SPW602 |
| LMR2S (/M) | Ø2" | 0.36" (9.1 mm) | Ø1.90" (Ø48.5 mm) | 1.36" (34.5 mm) | SM2RR | SPW604 |
*This specification is true for thin lenses. For lenses with small focal lengths, and hence large lens curvatures, please contact technical support to ensure a proper fit.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMR05S |
Ø1/2" Lens Mount with Internal and External SM05 Threads |
$23.00 |
Today |
LMR1S |
Customer Inspired!Ø1" Lens Mount with Internal and External SM1 Threads |
$25.00 |
Today |
LMR2S |
Ø2" Lens Mount with Internal and External SM2 Threads |
$29.00 |
Today |
LMR05S/M |
Metric, Ø1/2" Lens Mount with Internal and External SM05 Threads |
$23.00 |
Today |
LMR1S/M |
Customer Inspired!Metric, Ø1" Lens Mount with Internal and External SM1 Threads |
$25.00 |
Today |
LMR2S/M |
Metric, Ø2" Lens Mount with Internal and External SM2 Threads |
$29.00 |
Today |
These SM05, SM1, or SM2-threaded mounting rings feature internal SM threading that extends the full length of the mount without any retaining lip. They are perfect for mounting lens tubes and other mounted optics, and can also be used to hold unmounted optics when used with two retaining rings (sold separately below).
| Item # | Optic Diameter | Max Optic Thickness* | Clear Aperture | Optical Height | Compatible Retaining Ring (Not Included) | Spanner Wrench |
|---|---|---|---|---|---|---|
| SMR05 (/M) | Ø1/2" | 0.16" (4 mm) | Ø0.5" (Ø12.7 mm) | 0.63" (16.0 mm) | SM05RR | SPW603 |
| SMR1 (/M) | Ø1" | 0.24" (6.1 mm) | Ø1.0" (Ø25.4 mm) | 0.87" (22.1 mm) | SM1RR | SPW602 |
| SMR2 (/M) | Ø2" | 0.30" (7.6 mm) | Ø2.0" (Ø50.8 mm) | 1.35" (34.0 mm) | SM2RR | SPW604 |
*This specification is true for thin lenses. For lenses with small focal lengths, and hence large lens curvatures, please contact technical support to ensure a proper fit.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
SMR05 |
SM05 Series Adapter Ring |
$16.00 |
Today |
SMR1 |
SMR1 Mounting Ring for SM1 Series |
$17.00 |
Today |
SMR2 |
SMR2 Mounting Ring for SM2 Series |
$24.00 |
Today |
SMR05/M |
SM05 Series Adapter Ring |
$16.00 |
Today |
SMR1/M |
SMR1 Mounting Ring for SM1 Series (Metric) |
$17.00 |
Today |
SMR2/M |
Metric SMR2 Mounting Ring for SM2 Series |
$24.00 |
Today |
| Item # | Optic Diameter | Clear Aperture | Outer Diameter | Thickness | Compatible Mounts |
|
|---|---|---|---|---|---|---|
| Typ. | Max | |||||
| LMRA5 | Ø5 mm | Ø5.05 mm | Ø3.81 mm (Ø0.150") | Ø12.7 mm (Ø1/2") | 2.16 mm (0.085") | LMR05 Lens Mount SM05 Lens Tubes 16 mm Cage Plates, XY Translator, and Components |
| LMRA6 | Ø6 mm | Ø6.07 | Ø4.82 mm (Ø0.190") | |||
| LMRA6.35 | Ø6.35 mm | Ø6.4 | Ø5.38 mm (Ø0.212") | |||
| LMRA7 | Ø7 mm | Ø7.03 | Ø6.04 mm (Ø0.238") | |||
| LMRA7.4 | Ø7.4 mm | Ø7.41 | Ø6.35 mm (Ø0.250") | |||
| LMRA8 | Ø8 mm | Ø8.02 | Ø6.98 mm (Ø0.275") | |||
| LMRA9 | Ø9 mm | Ø9.01 | Ø7.87 mm (Ø0.310") | |||
| LMRA10 | Ø10 mm | Ø10.03 | Ø8.76 mm (Ø0.345") | Ø18 mm (Ø0.71") | 2.54 mm (0.100") | LMR18 Lens Mount |
The optic adapter is designed to allow the lens to be epoxied into place (NOA61 epoxy recommended); simply place a drop or two of epoxy into each of the epoxy reservoirs in the adapter. Once the optic is secured in the adapter, the new assembly can be held in our LMR05 (LMR18 for LMRA10) mount with the included SM05RR (SM18RR) Retaining Ring.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMRA5 |
LMR05 Adapter for Ø5 mm Optics |
$15.00 |
Today |
LMRA6 |
LMR05 Adapter for Ø6 mm Optics |
$15.00 |
Today |
LMRA6.35 |
LMR05 Adapter for Ø6.35 mm Optics |
$15.00 |
Today |
LMRA7 |
LMR05 Adapter for Ø7.0 mm Optics |
$13.80 |
Today |
LMRA7.4 |
LMR05 Adapter for Ø7.4 mm Optics |
$13.80 |
Today |
LMRA8 |
LMR05 Adapter for Ø8.0 mm Optics |
$15.00 |
Today |
LMRA9 |
LMR05 Adapter for Ø9.0 mm Optics |
$15.00 |
Today |
LMRA10 |
LMR18 Adapter for Ø10.0 mm Optics |
$20.00 |
Today |

These alignment tools can be quickly and easily dropped onto one of our fixed lens holder or lens tubes allowing the user to align a visible beam, using the Ø1 mm through-hole in the center. Once the beam is aligned, the tool can be removed without disturbing the alignment. The plates feature eight 1 mm engraved concentric circles for optimal visual alignment of the beam when used with our LMR series fixed optics mounts and SM series lens mounts.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
LMR1AP |
Customer Inspired!Alignment Plate for LMR1 Mount and SM1 Lens Tubes |
$22.00 |
Today |
LMR2AP |
Customer Inspired!Alignment Plate for LMR2 Mount and SM2 Lens Tubes |
$26.00 |
Today |
These retaining rings are replacements for those that are provided with our fixed lens mounts featured above. We also offer stress-free and plastic retaining rings for our Ø1.0" lens mounts, and retaining rings in additional sizes on our main SM-Threaded Retaining Rings presentation.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
SM05RR |
SM05 Retaining Ring for Ø1/2" Lens Tubes and Mounts |
$4.00 |
Today |
SM15RR |
SM15 Retaining Ring for Ø15 mm Lens Mounts |
$9.50 |
Today |
SM18RR |
SM18 Retaining Ring for Ø18 mm Lens Mounts |
$9.50 |
Today |
SM20RR |
SM20 Retaining Ring for Ø20 mm Lens Mounts |
$9.50 |
Today |
SM1RR |
SM1 Retaining Ring for Ø1" Lens Tubes and Mounts |
$4.50 |
Today |
SM30RR |
SM30 Retaining Ring for Ø30 mm Lens Mounts |
$11.00 |
Today |
SM1.5RR |
SM1.5 Retaining Ring for Ø1.5" Lens Mounts |
$9.50 |
Today |
SM45RR |
SM45 Retaining Ring for Ø45 mm Lens Mounts |
$12.20 |
Today |
SM2RR |
SM2 Retaining Ring for Ø2" Lens Tubes and Mounts |
$6.75 |
Today |
SM75RR |
SM75 Retaining Ring for Ø75 mm Mounts |
$14.30 |
Today |
SM3RR |
SM3 Retaining Ring for Ø3" Lens Tubes and Mounts |
$14.30 |
Today |
SM100RR |
SM100 Retaining Ring for Ø100 mm Mounts |
$16.60 |
Today |
SM4RR |
Customer Inspired!SM4 Retaining Ring for Ø4" Mounts |
$16.60 |
Today |
The hollow construction of these spanner wrenches allows SM-series retaining rings to be installed or adjusted without obscuring the beam path. They include guide flanges that prevent most optical surfaces from being scratched while the wrench is being inserted, and knurled handles that provide improved grip.
As shown to the right, the SPW602 additionally features an engraved depth scale with imperial and metric increments (0.02" and 0.5 mm, respectively), thereby enabling precise positioning of optics.
For retaining rings not covered by our standard spanner wrenches, please see the SPW801 Adjustable Spanner Wrench sold at the bottom of the page. The long blades on the SPW801 also prevent scratches caused by the guide flanges on lenses with high curvature.
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
SPW603 |
SM05 Spanner Wrench, Length = 1" |
$24.00 |
Today |
SPW606 |
Customer Inspired!SM1 Spanner Wrench, Length = 1" |
$26.00 |
Today |
SPW602 |
SM1 Spanner Wrench, Graduated, Length = 3.88" |
$26.00 |
Today |
SPW607 |
Customer Inspired!SM30 Spanner Wrench, Length = 4.35" |
$40.00 |
Today |
SPW604 |
Customer Inspired!SM2 Spanner Wrench, Length = 4.35" |
$43.40 |
Today |
SPW605 |
SM3 Spanner Wrench, Length = 4.35" |
$76.50 |
Today |
Thorlabs' Adjustable Spanner Wrench features a spanning range that is continuously adjustable from 0.12" to 2.89" (3.0 mm to 73.4 mm). It is capable of providing an exact fit for SM-series retaining rings as large as the SM3RR for Ø3" Lens Tubes and Mounts. The diameter spanned by the blades remains centered while the knurled knob is adjusted.
The reversible blades have a flat tip on one end intended for use with retaining rings, and an edge-offset fine point on the opposing end for adapters with holes. The blades extend 1.6" (40.7 mm) from the body of the wrench, helping to avoid scratching of short-focal-length lenses caused by the guide flanges on our standard spanner wrenches. To reverse the blades, a 0.050" (1.3 mm) balldriver or hex key is needed. Replacement blade pairs are available separately.
The SPW801 wrench withstands a maximum torque of 80 inch-pounds (9 N•m).
Part Number |
Description |
Price |
Availability |
|---|---|---|---|
SPW801 |
Adjustable Spanner Wrench |
$95.90 |
Today |
SPW102 |
Adjustable Spanner Wrench, Replacement Blade Set |
$27.90 |
Today |