Ø1" Lens Tubes

Lens Tubes Accept Ø1" (25.4 mm) Optics
SM1 Thread Standard Used Throughout Thorlabs' Product Line
Designed for Use with Our 30 mm Cage Systems

SM1M10

Internal Threads

SM1S20

External Threads

SM1L05V

Internal and External Threads

SM1L40

Internal and External Threads

SM1L10E

Internal Threads, Optic Retention Lip

SM1L30C

Slotted Lens Tube
(Optic Not Included)

Easily Interfaces with Other Lens
Tube Sizes

SM05

SM1

SM2

SM3

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OVERVIEW

Ø1" Shortcuts
Lens Tube Couplers SM Thread Adapters Lens Tube Mounts End Caps Kinematic Mounts Fixed Lens Mounts Rotational Mounts Translation Mounts

Additional Lens Tube Sizes
Ø1/2" Ø30 mm Ø1.5" Ø2" Ø3"

Features

Variety of Lens Tubes in Lengths from 0.30" (7.6 mm) to 4.00" (101.6 mm)

Standard Lens Tubes
Lens Tubes without External Threading
Lens Tubes with Optic Retention and No External Threading
Lens Tube Spacers without Internal Threading
Slotted Lens Tubes for Access to Optics without Disassembly

Extension Tube for Optics with Long Focal Lengths
Wide Range of SM1 (1.035"-40) Compatible Optomechanical Components
Compatible with Our 30 mm Cage Systems
Vacuum-Compatible Options Available
Lens Tubes Directly Accept Ø1" (Ø25.4 mm) Optics

Lens tubes are ideal for creating compact optical subassemblies with light-tight beam paths. The Ø1" lens tubes sold here can be used to house one or several optical elements, as shown in the diagram of a beam expander below. In addition to the Ø1" lens tubes featured on this page, Thorlabs also offers Ø1/2", Ø30 mm, Ø1.5", Ø2", and Ø3" versions, each of which is equipped with an SM series thread standard that depends on the tube diameter. Vacuum-compatible versions of our Ø1/2" and Ø1" stackable lens tubes are available from stock; customers can request vacuum-compatible lens tubes at other lengths and diameters by contacting Tech Support.

Optics are separated and secured by retaining rings at the desired depth within the lens tube using a compatible SM1 spanner wrench, sold below. Each of the lens tubes on this page come with one or two compatible SM-threaded retaining rings with the exception of the internally unthreaded lens tube spacers (Item #'s beginning with SM1S). In addition, Thorlabs offers stress-free and plastic retaining rings for optics which require reduced stress on our Retaining Rings page.

Click to Enlarge
When an engraved lens tube is attached to another lens tube, the engraving of the connected end is no longer visible.

Lens Tube Compatible Products
Thread Adapters	Terminated Fiber Adapters	Fixed Fiber Collimator Adapters	Kinematic Fiber Collimator Adapters	LED Mounts	LD Mounts	Aspheric Lens Mounts	Irises, Apertures, and Shutters	Alignment Tools

Hide Threading Specs

THREADING SPECS

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Threading Specifications

The following is a general overview of screw threading. For more details regarding specifications and dimensions, please consult the Machinery's Handbook, available for purchase at many bookstores.

Features of a Thread
A thread consists of three repeating features: a crest, flank, and root (see drawing to the right). Except in special cases, threads have symmetrical sides inclined at equal angles when a vertical line is drawn through the center of a crest or root. The distance between corresponding points on adjacent threads is known as the pitch of the thread. The flank angle is defined as the angle the flank makes with a perpendicular ray drawn from the screw axis. Unless otherwise stated, threads have a flank angle of 30°, resulting in a total angle between flanks of 60°. Each feature is shown in the diagram to the right.

The major diameter is taken from the crests of a thread while the minor diameter is taken from the roots. For most screws, crests and roots do not terminate at a sharp point, so crest and root truncation values are included in the definitions of major and minor diameter. The pitch diameter is approximately halfway between the major and minor diameters.

Thread Form
A thread form is a set of rules that define the features' scale relative to one another. Common thread forms include the Unified Screw Thread Form, used in the United States of America and measured in imperial units, and the ISO Metric Screw Thread Form, used in many parts of the world and measured with the International System of Units. There are many thread forms in the Unified screw thread standard designated by either UN, which defines a flat root contour, or UNR, which defines a round root contour. These can be further described by appending more letters. For example, an extremely fine thread with a flat root contour is designated UNEF. Those forms which are not standardized by the Unified screw thread system are designated UNS.

Thread Series
Most screws are identified by their thread series. Thread series are denoted by the major diameter and density of threads. Unified threads specify density in threads per inch, while Metric threads specify the thread pitch. For example, in the Unified nomenclature, a 1/4"-20 cap screw has a 1/4" diameter barrel and the pitch is 20 threads per inch (TPI). In metric nomenclature, an M4 x 0.7 cap screw has a 4 mm barrel and the pitch is 1 thread per 0.7 mm. The term M4 x 0.7 is often shortened to just M4.

Unified Thread Class Tolerancing
Location	Loose	Optimal	Strict
Internal	1B	2B	3B
External	1A	2A	3A

Metric Thread Tolerance Positions
Location	Loose	Optimal	Strict
Internal	-	G	H
External	e or f	g	h

Metric Thread Tolerance Grades
Dimension	Location	Tolerance Grades^a
Minor Diameter	Internal	4, 5, 6, 7, 8
Major Diameter	External	4, 6, 8
Pitch Diameter	Internal	4, 5, 6, 7, 8
Pitch Diameter	External	3, 4, 5, 6, 7, 8, 9

The tolerance becomes looser as the grade increases. The underlined grades are used with normal lengths of thread engagement.

Thread Class
The tolerances and allowances on a thread series are given by a thread class. Unified thread classes are alphanumeric identifiers starting with a number from 1 through 3, where 1 is the loosest tolerance and 3 is the tightest, and either A for external threading or B for internal threading.

Metric threads have a slightly more complex tolerancing method that uses tolerancing grades, designated by a number 3 through 9; and tolerancing positions, which use letters e through h. Grades provide a measure of the tolerance itself: the smaller the number, the tighter the tolerance. Positions denote the distance of the tolerance from the pitch diameter. Uppercase positioning letters indicate internal threads while lowercase positioning letters indicate external threads.

Quoting from the Machinery's Handbook, 29th Edition, p. 1885: "To designate the tolerance class, the grade and position of the pitch diameter is shown first followed by that for the major diameter in the case of the external thread or that for the minor diameter in the case of the internal thread, thus 4g6g for an external thread and 5H6H for an internal thread. If the two grades and positions are identical, it is not necessary to repeat the symbols, thus 4g, alone, stands for 4g4g and 5H, alone, stands for 5H5H."

Thorlabs' SM Series Threads
Threading specifications for our SM threads, utilized in our lens tube and cage system components, are given below so that you can machine mating components to suit your application. Most SM series threads utilize a non-standard Unified thread form, indicated by the letters UNS, with a 30° flank angle and a thread class of 2A and 2B. The exception is our SM30 series thread, which is a Metric thread form with a 30° flank angle and a tolerance of 6H/6g. We also offer products with C-Mount and RMS threads, and the specifications for these threads are given below for reference. Please note that other manufacturers may have different tolerances for C-Mount and RMS 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, M30.5 x 0.5 – 6H/6g		Internal Thread, M30.5 x 0.5 – 6H/6g
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" Lens Tubes
External Thread, 4.035"-40 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"

Hide Ø1" Stackable Lens Tubes

Ø1" Stackable Lens Tubes

Stackable Design Enables Multi-Element Optical Systems
SM1-Threaded (1.035"-40) Bore Accepts Ø1" (Ø25.4 mm) Optics
Compatible with Our 30 mm Cage Systems
0.30", 0.50", 1.00", and 2.00" Lengths Available in Packs of 5

These stackable Ø1" lens tubes provide a fast and easy means for building compact optical assemblies. Their stackable design and direct interfacing with any SM1-threaded (1.035"-40) components provide flexibility for complex optomechanical assemblies. One SM1RR Retaining Ring is included with each lens tube.

For convenience, four of our most popular SM1 lens tube sizes are also available in packs of 5. Each pack of 5 includes one retaining ring per lens tube for a total of five rings.

Item #	L	Internal Thread Depth
SM1L03	0.33" (8.4 mm)	0.30" (7.6 mm)
SM1L05	0.53" (13.5 mm)	0.50" (12.7 mm)
SM1L10	1.03" (26.2 mm)	1.00" (25.4 mm)
SM1L15	1.53" (38.9 mm)	1.50" (38.1 mm)
SM1L20	2.03" (51.6 mm)	2.00" (50.8 mm)
SM1L25	2.53" (64.3 mm)	2.50" (63.5 mm)
SM1L30	3.03" (77.0 mm)	3.00" (76.2 mm)
SM1L35	3.53" (89.7 mm)	3.50" (88.9 mm)
SM1L40	4.03" (102.4 mm)	4.00" (101.6 mm)

Alternatives	Ø1/2", Ø30 mm, Ø1.5", Ø2", and Ø3" Stackable Lens Tubes

Part Number	Description	Price	Availability
SM1L03	SM1 Lens Tube, 0.30" Thread Depth, One Retaining Ring Included	$13.15	Today
SM1L03-P5	SM1 Lens Tube, 0.30" Thread Depth, SM1RR Retaining Ring, 5 Pack	$62.45	Today
SM1L05	SM1 Lens Tube, 0.50" Thread Depth, One Retaining Ring Included	$13.62	Today
SM1L05-P5	SM1 Lens Tube, 0.50" Thread Depth, SM1RR Retaining Ring, 5 Pack	$64.67	Today
SM1L10	SM1 Lens Tube, 1.00" Thread Depth, One Retaining Ring Included	$15.41	Today
SM1L10-P5	SM1 Lens Tube, 1.00" Thread Depth, SM1RR Retaining Ring, 5 Pack	$73.22	Today
SM1L15	SM1 Lens Tube, 1.50" Thread Depth, One Retaining Ring Included	$16.98	Today
SM1L20	SM1 Lens Tube, 2.00" Thread Depth, One Retaining Ring Included	$17.85	Today
SM1L20-P5	SM1 Lens Tube, 2.00" Thread Depth, SM1RR Retaining Ring, 5 Pack	$84.79	Today
SM1L25	SM1 Lens Tube, 2.50" Thread Depth, One Retaining Ring Included	$22.83	Today
SM1L30	SM1 Lens Tube, 3.00" Thread Depth, One Retaining Ring Included	$29.23	Today
SM1L35	SM1 Lens Tube, 3.50" Thread Depth, One Retaining Ring Included	$40.54	Today
SM1L40	SM1 Lens Tube, 4.00" Thread Depth, One Retaining Ring Included	$49.64	Today

Hide Vacuum-Compatible Ø1" Stackable Lens Tubes

Vacuum-Compatible Ø1" Stackable Lens Tubes

Vacuum Specifications
Vacuum Compatibility as Packaged^a	>10^-6 Torr
Materials	6061-T6 Aluminum
Preparation and Packaging	Chemically Cleaned and Double Vacuum-Bagged
Aluminum Outgassing Rate at 20 °C	7.6 x 10^-9 Torr-Liters/s/cm²

This is the pressure at which these components can be used with no additional processing. They can be used at even lower pressures with additional cleaning and processing.

Stackable Design Enables Multi-Element Optical Systems
SM1-Threaded (1.035"-40) Bore Accepts Ø1" (Ø25.4 mm) Optics
Compatible with SM1-Threaded Vacuum Components
0.30", 0.50", and 1.00" Lengths Available

These stackable Ø1" lens tubes provide a fast and easy means for building compact optical assemblies. Their stackable design and direct interfacing with any SM1-threaded (1.035"-40) components provide flexibility for complex optomechanical assemblies. Made from 6061-T6 aluminum, these lens tubes are vacuum compatible down to 10^-6 Torr. One SM1RRV Vacuum-Compatible Retaining Ring is included with each lens tube.

These vacuum-compatible lens tubes feature venting channels along the internal threading and at the ends of each tube. These channels allow air trapped between mounted optics an easy means of escape during pumpdown.

Click to Enlarge
Vents along the threading and at the ends of these tubes provide a free path for air to escape when under vacuum.

Item #	L	Internal Thread Depth
SM1L03V	0.33" (8.4 mm)	0.30" (7.6 mm)
SM1L05V	0.53" (13.5 mm)	0.50" (12.7 mm)
SM1L10V	1.03" (26.2 mm)	1.00" (25.4 mm)

Alternatives	Ø1/2" Vacuum-Compatible Stackable Lens Tube

Part Number	Description	Price	Availability
SM1L03V	Vacuum-Compatible SM1 Lens Tube, 0.30" Thread Depth, One Retaining Ring Included	$42.97	Today
SM1L05V	Vacuum-Compatible SM1 Lens Tube, 0.50" Thread Depth, One Retaining Ring Included	$43.54	Today
SM1L10V	Vacuum-Compatible SM1 Lens Tube, 1.00" Thread Depth, One Retaining Ring Included	$48.89	Today

Hide Ø1" Lens Tubes Without External Threads

Ø1" Lens Tubes Without External Threads

Unlike Stackable Lens Tubes, Optics can be Accessed from Both Ends
SM1-Threaded (1.035"-40) Bore Accepts Ø1" (Ø25.4 mm) Optics
Use Lens Tube Couplers to Stack Multiple Lens Tubes
Allows Coupling of Two Externally SM1-Threaded Components

Unlike our Ø1" stackable lens tubes featured above, these internally threaded lens tubes do not feature a lip at one end nor do they have external SM1 threading. Therefore, optics housed inside can be accessed from both ends. To join these lens tubes end-to-end, use a Lens Tube Coupler. Two SM1RR Retaining Rings are included with each lens tube.

Alternatives	Ø1/2" and Ø2" Lens Tubes Without External Threads

Part Number	Description	Price	Availability
SM1M05	Customer Inspired! SM1 Lens Tube Without External Threads, 1/2" Long, Two Retaining Rings Included	$15.36	Today
SM1M10	Customer Inspired! SM1 Lens Tube Without External Threads, 1" Long, Two Retaining Rings Included	$16.96	Today
SM1M15	SM1 Lens Tube Without External Threads, 1.5" Long, Two Retaining Rings Included	$19.84	Today
SM1M20	Customer Inspired! SM1 Lens Tube Without External Threads, 2" Long, Two Retaining Rings Included	$19.84	Today
SM1M25	SM1 Lens Tube Without External Threads, 2.5" Long, Two Retaining Rings Included	$21.33	Today
SM1M30	Customer Inspired! SM1 Lens Tube Without External Threads, 3" Long, Two Retaining Rings Included	$21.33	Today
SM1M35	SM1 Lens Tube Without External Threads, 3.5" Long, Two Retaining Rings Included	$34.30	Today

Hide Ø1" Lens Tubes Without External Threads, Optic Retention Lip

Ø1" Lens Tubes Without External Threads, Optic Retention Lip

Item #	L	Thread Depth
SM1L05E	0.54" (13.7 mm)	0.50" (12.7 mm)
SM1L10E	1.04" (26.4 mm)	1.00" (25.4 mm)

Internal SM1 Threading (1.035"-40) with Optic Retention Lip at One End
Quickly Add and Remove Optics from Ø1" Lens Tube Assemblies
1/2" (12.7 mm) and 1" (25.4 mm) Thread Depths Available
Ø0.90" (Ø22.9 mm) Clear Aperture

These lens tubes feature internal SM1 threading on one end and a retaining lip for holding optics on the other. They allow optics to be quickly added to any externally SM1-threaded components. The SM1L05E is 1/2" (12.7 mm) long and can hold optics up to 0.3" (8 mm) thick, while the SM1L10E is 1" (25.4 mm) long and can hold optics up to 0.8" (20 mm) thick. Each segment includes an SM1RR retaining ring for securing the optic into place. The retaining ring provides a clear aperture of Ø0.90" (Ø22.9 mm) through the lens tube.

These lens tubes are engraved with their respective part number at the end, as shown in the image to the left. This engraving is hidden when the lens tubes are combined with other SM1-threaded components.

Part Number	Description	Price	Availability
SM1L05E	Customer Inspired! SM1 Lens Tube Without External Threads, Optic Retention Lip, 1/2" Thread Depth, One Retaining Ring Included	$14.62	Today
SM1L10E	Customer Inspired! SM1 Lens Tube Without External Threads, Optic Retention Lip, 1" Thread Depth, One Retaining Ring Included	$16.74	Today

Hide Ø1" Lens Tube Spacers Without Internal Threads

Ø1" Lens Tube Spacers Without Internal Threads

Use as Spacers Between Lens Tubes
External SM1 Threading (1.035"-40) on Each End
Ø0.95" (Ø24.0 mm) Clear Aperture
Lengths Ranging from 1.0" (25.4 mm) to 3.5" (88.9 mm)

These Lens Tube Spacers are designed to connect two components with internal SM1 threads at a fixed distance. They are internally unthreaded and have a clear aperture of Ø0.95" (Ø24.0 mm).

Please note that due to the fixed thread depth of 0.12" (3.0 mm), the orientation of the attached components will be arbitrary. For full control over the component orientation, Thorlabs offers Lens Tube Couplers with adjustable locking rings.

Part Number	Description	Price	Availability
SM1S10	Customer Inspired! SM1 Lens Tube Spacer, 1" Long	$14.62	Today
SM1S15	SM1 Lens Tube Spacer, 1.5" Long	$16.99	Today
SM1S20	Customer Inspired! SM1 Lens Tube Spacer, 2" Long	$16.99	Today
SM1S25	SM1 Lens Tube Spacer, 2.5" Long	$24.23	Today
SM1S30	Customer Inspired! SM1 Lens Tube Spacer, 3" Long	$24.23	Today
SM1S35	SM1 Lens Tube Spacer, 3.5" Long	$28.03	Today

Hide Ø1" Slotted Lens Tubes

Ø1" Slotted Lens Tubes

Click to Enlarge
The dust cover can be opened or closed by rotating it in either direction.

Easy Access to Optics
Rotatable Slip Shield Protects Optics
Compatible with SM1-Threaded (1.035"-40) Components
Available in 1", 2", and 3" Thread Depths

These stackable Ø1" lens tubes with side slots provide a fast and easy means for building complex optical assemblies and adjusting the optics without disassembling the setup. Optics can be inserted into the tube and locked into position using the included SM1RR retaining rings. Simply thread the first retaining ring to the desired depth, add the optic, and then use a second retaining ring to secure the optic. Optics can be manually adjusted via the side slots without the use of a spanner wrench. The included rotatable slip shield, with an inner diameter of 1.21" (31.0 mm), fits over the lens tube slots to prevent unwanted light from entering the system and to keep the optical setup free from debris.

Item #	L₁	L₂	Internal Thread Depth
SM1L10C	1.03" (26.2 mm)	0.80" (20.3 mm)	1.00" (25.4 mm)
SM1L20C	2.03" (51.6 mm)	1.30" (33.0 mm)	2.00" (50.8 mm)
SM1L30C	3.03" (77.0 mm)	2.30" (58.4 mm)	3.00" (76.2 mm)

Alternatives	Ø1/2" and Ø2" Slotted Lens Tubes

Part Number	Description	Price	Availability
SM1L10C	Customer Inspired! SM1 Slotted Lens Tube, 1" Thread Depth, 2 Retaining Rings Included	$65.87	Today
SM1L20C	SM1 Slotted Lens Tube, 2" Thread Depth, 2 Retaining Rings Included	$72.77	Today
SM1L30C	SM1 Slotted Lens Tube, 3" Thread Depth, 2 Retaining Rings Included	$79.00	Today

Hide Ø1" Extension Tubes

Ø1" Extension Tubes

Extra-Long 6" (152.4 mm) Tube for Optics with Large Focal Lengths
1.00" (25.4 mm) Long, SM1-Threaded (1.035"-40) Bore Accepts Ø1" (Ø25.4 mm) Optics
Compatible with 30 mm Cage Systems

The SM1E60 6" Long Extension Tube is designed to enable longer distances between optical components in lens tube systems that utilize lenses with large focal lengths. This tube features thicker walls than our standard lens tubes while maintaining the same outer diameter, which leads to greater rigidity.

Alternatives	Ø2" Extension Tubes

Part Number	Description	Price	Availability
SM1E60	SM1 Extension Tube, 6" Long, 1" Thread Depth, One Retaining Ring Included	$53.47	Today

Hide Ø1" Retaining Rings and Spanner Wrenches

Ø1" Retaining Rings and Spanner Wrenches

Retaining Ring Specs
Item #	Material	Feature	Thickness	Inner Diameter
SM1RR	Black Anodized Aluminum	Standard	0.08" (2.0 mm)	0.90" (22.9 mm)
SM1RRV	Unanodized Aluminum	Vacuum Compatible^a	0.08" (2.0 mm)	0.90" (22.9 mm)
SM1LTRR	Black Anodized Aluminum	Rubber O-Ring for Stress-Free Mounting	0.16" (3.9 mm)	0.82" (20.7 mm)
SM1RRC	Black Anodized Aluminum	5 mm Thick for High-Curvature Lenses	0.20" (5.0 mm)	0.90" (22.9 mm)
SM1PRR	Plastic	Non-Marring	0.11" (2.8 mm)	0.80" (20.3 mm)
POLARIS-SM1RR	Stainless Steel	Vacuum Compatible^b	0.08" (2.0 mm)	0.90" (22.9 mm)

>10^-6 Torr Vacuum Compatibility as Packaged; Lower Pressures with Additional Cleaning and Processing
>10^-5 Torr at 25 °C Vacuum Compatibility as Packaged without Bake Out; >10^-9 Torr at 25 °C with Proper Bake Out

Six Types of Retaining Rings for Securing Ø1" Optics
Multiple Hollow Spanner Wrenches Providing Unobstructed Beam Path During Adjustment
SPW801 Adjustable Spanner Wrench Accommodates Diameters from 0.12" (3.0 mm) to 2.89" (73.4 mm)

The SM1RR is our standard anodized aluminum retaining ring that ships with our Ø1" lens tubes as well as many other Thorlabs components and is available individually and in packs of 10. We offer six different SM1-threaded (1.035"-40) retaining rings, shown in the table to the right, which have unique features and can replace an SM1RR retaining ring. Please keep in mind that due to the increased thickness of some retaining rings, the maximum optic thickness that can be housed inside our standard SM1-compatible mounts will be diminished in some cases.

Click to Assemble
Spanner Wrench Usage

Spanner Wrenches
The 1" long SPW606 and the 3.87" long SPW602 have a hollow design that enables retaining rings with inner diameters of 0.90" to be adjusted and installed in our SM01 series of lens tubes without obscuring the beam path, as shown to the right. Their handles are knurled for improved grip. In addition, the SPW602 wrench has graduations along its side to judge lens depth within a lens tube.

Alternatively, the SPW801 Adjustable Spanner Wrench can be used to position any SM1-threaded retaining ring. Please note that the SPW801 wrench can withstand a maximum torque of 80 inch-pounds. We also offer the SPB1 Spanner Bit, which can be used with a standard 1/4" hex driver (sold separately). The SPB1 is included as part of the SPB600 Spanner Wrench Bit Kit.

Alternatives	Ø1/2", Ø2", and Ø3" Fixed Diameter Spanner Wrenches	Ø1/2", Ø1.5", Ø2", and Ø3" Retaining Rings

Part Number	Description	Price	Availability
SM1RR	SM1 Retaining Ring for Ø1" Lens Tubes and Mounts	$4.87	Today
SM1RR-P10	SM1 Retaining Ring for Ø1" Lens Tubes and Mounts, 10 Pack	$43.81	Today
SM1RRV	Customer Inspired! Unanodized Aluminum SM1 Retaining Ring for Ø1" Lens Tubes and Mounts	$12.01	Today
SM1LTRR	SM1 (1.035"-40) Stress-Free Retaining Ring	$26.01	Today
SM1RRC	Extra-Thick SM1 (1.035"-40) Threaded Retaining Ring	$12.24	Today
SM1PRR	Customer Inspired! SM1 (1.035"-40) Plastic Retaining Ring for Ø1" Lens Tubes and Mounts	$6.48	Today
POLARIS-SM1RR	Customer Inspired! Stainless Steel SM1 (1.035"-40) Threaded Retaining Ring	$13.16	Today
SPW606	Customer Inspired! Spanner Wrench for SM1-Threaded Retaining Rings, Length = 1.00"	$31.15	Today
SPW602	Spanner Wrench for SM1-Threaded Retaining Rings, Graduated Scale with 0.02" (0.5 mm) Increments, Length = 3.88"	$31.15	Today
SPW801	Adjustable Spanner Wrench	$114.14	Today
SPW102	Adjustable Spanner Wrench, Replacement Blade Set	$33.20	Today