SM2-Compatible Rotation Mounts

Mount Ø2" (Ø50.8 mm) Optics or SM2 (Ø2.035"-40) Lens Tubes
360° Continuous Rotation

LC1AR

Swivel Mount for
60 mm Cage Systems

RSP2

Ø2" Rotation Mount

LCRM2A

Ø2" Rotation Mount for
60 mm Cage Systems

KS2RS

Ø2" Kinematic Rotation Mount

Related Items

SM2 Lens Tubes

60 mm Cage System XY Translation Mounts

Cage Systems

Lab Safety

Right Angle Prisms

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Overview
Threading Specs
Feedback
Rotation Mounts and Stages

Quick Links
High-Precision Rotation Mount	Continuous Rotation Mount
Continuous Rotation Mount with Adjustable Zero	Ø1" Nested Optic Mount
Ø2" Kinematic Rotation Mount	6-Axis Kinematic Optic Mount
60 mm Cage Rotation Mount	60 mm Cage Rotation Mount, ±8° Fine Rotation Adjustment
Swivel Mounts/Plates for 60 mm Cage Systems

Features

Rotation Mounts with Internal SM2 (2.035"-40) Threads
Compatible with SM2-Threaded Components
Engraved Scale

This page has a compilation of rotation mounts that feature internal SM2 (2.035"-40) threads and can mount Ø2" (Ø50.8 mm) optics, SM2 lens tubes, or other SM2-threaded components. Each mount allows for 360° rotation of an optic, SM2-threaded component, or platform.

Thorlabs introduced the SM Thread Standards to ensure compatibility over a broad range of product lines. SM-threaded components offer a simple and efficient solution for building optomechanical structures. Our SM-threaded products, including lens tubes and cage system components, fixed and kinematic mounts, irises and diaphragms, provide flexibility when constructing complex optical systems. Please see the Threading Specs tab for more information on Thorlabs' SM thread standards.

Thorlabs also has similar compilations of SM-threaded rotation mounts for Ø1/2" (Ø12.7 mm) and Ø1" (Ø25.4 mm) optics. For our entire selection of rotation mounts, please see the Rotation Mounts and Stages tab.

Click to Enlarge

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"

Posted Comments:

Wolfgang Lakata (posted 2021-04-21 07:53:10.97)

Dear Sir or Madame, a cage-mounting system for gratings would be really helpful with easy adjustable angles for the grating and the reflected beam in order to build a spectrograph. Best regards, Wolfgang Lakata

YLohia (posted 2021-04-29 01:44:00.0)

Hello Wolfgang, thank you for your feedback. We will consider offering parts specifically for such applications in the future. That being said, we currently offer the C3A Jointed Cage Assembly Rod / Swivel Connector that can be used with CYCP 30 mm Cage Mount for Cylindrical Lenses (or other rectangular optics) for a similar effect.

Rotation Mount and Stage Selection Guide

Thorlabs offers a wide variety of manual and motorized rotation mounts and stages. Rotation mounts are designed with an inner bore to mount a Ø1/2", Ø1", or Ø2" optic, while rotation stages are designed with mounting taps to attach a variety of components or systems. Motorized options are powered by a DC Servo motor, 2 phase stepper motor, piezo inertia motor, or an Elliptec™ resonant piezo motor. Each offers 360° of continuous rotation.

Manual Rotation Mounts

Rotation Mounts for Ø1/2" Optics
Item #	MRM05(/M)	RSP05(/M)	CRM05	PRM05(/M)^a	SRM05	KS05RS	CT104
Click Photo to Enlarge
Features	Mini Series	Standard	External SM1 (1.035"-40) Threads	Micrometer	16 mm Cage-Compatible	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Compatible with 30 mm Cage Translation Stages and 1/4" Translation Stages^b
Additional Details

This mount is available in the PRM05GL5 bundle, which includes the PRM05 rotation mount with the SM05PM5 polarizing prism mount.
The CT104 is complatible with the 1/4" translation stages using our MS103(/M) adapter plate.
The CT104 is compatible with the CT1A(/M) cage translation stage, which is designed for use with 30 mm cage systems.

Rotation Mounts for Ø1" Optics
Item #	RSP1(/M)	LRM1	RSP1D(/M)	DLM1(/M)	CLR1(/M)	RSP1X15(/M)	RSP1X225(/M)	PRM1(/M)^a
Click Photo to Enlarge
Features	Standard	External SM1 (1.035"-40) Threads	Adjustable Zero	Two Independently Rotating Carriages	Rotates Optic Within Fixed Lens Tube System	Continuous 360° Rotation or 15° Increments	Continuous 360° Rotation or 22.5° Increments	Micrometer
Additional Details

This mount is available in the PRM1GL10 bundle, which includes the PRM1 rotation mount with the SM1PM10 polarizing prism mount.

Rotation Mounts for Ø1" Optics
Item #	LM1-A & LM1-B(/M)	CRM1T(/M)	CRM1LT(/M)	CRM1PT(/M)	KS1RS	K6XS
Click Photo to Enlarge
Features	Optic Carriage Rotates Within Mounting Ring	30 mm Cage-Compatible^a	30 mm Cage-Compatible for Thick Optics^a	30 mm Cage-Compatible with Micrometer^a	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Six-Axis Kinematic Mount^a
Additional Details

This mount also features four 4-40 (M3) holes on the rotation dial for use with the K6A1(/M) prism platform.

Rotation Mounts for Ø2" Optics
Item #	RSP2(/M)	RSP2D(/M)	PRM2(/M)	LM2-A & LM2-B(/M)	LCRM2A(/M)	KS2RS	K6X2
Click Photo to Enlarge
Features	Standard	Adjustable Zero	Micrometer	Optic Carriage Rotates Within Mounting Ring	60 mm Cage-Compatible	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Six-Axis Kinematic Mount
Additional Details

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous		Coarse: Manual, 360° Continuous; Fine: ±7° Micrometer	Manual, 360° Continuous
Optic Mounting	Internally SM2-Threaded Carriage			Internal SM2 Threads in LM2-A	Internally SM2-Threaded Carriage
Maximum Accepted Optic Thickness	0.51" (13 mm)	0.54" (13.7 mm)	0.48" (12.2 mm)	0.46" (11.7 mm)	0.52" (13.2 mm)	0.47" (12 mm)	0.53" (13.4 mm)
Post Mounting	8-32 (M4) Tap			8-32 (M4) Tap in LM2-B	8-32 (M4) Tap	Four Counterbores for 8-32 (M4) Cap Screws	Six Counterbores for 8-32 (M4) Cap Screws
Cage System Compatibility	N/A		Four 4-40 (M3) Taps on Rotation Dial with 60 mm Spacing	N/A	Four Bores for Ø6 mm Cage Rods with 60 mm Spacing	N/A	N/A

Manual Rotation Stages

Manual Rotation Stages
Item #	RP005(/M)	PR005(/M)	MSRP01(/M)	RP01(/M)	RP03(/M)	QRP02(/M)
Click Photo to Enlarge
Features	Standard					Two Hard Stops
Additional Details

Manual Rotation Stages
Item #	XRNR1(/M)	XRR1(/M)	PR01(/M)	CR1(/M)	XYR1(/M)	OCT-XYR1(/M)
Click Photo to Enlarge
Features	Fine Rotation Adjuster and 2" Wide Dovetail Quick Connect	Fine Rotation Adjuster and 3" Wide Dovetail Quick Connect	Fine Rotation Adjuster and SM1-Threaded Central Aperture	Fine Pitch Worm Gear	Rotation and 1/2" Linear XY Translation
Additional Details

The stage profile is higher when it is mounted using the screw slots rather than stacked on another stage or accessory with mating dovetails.
The OCT-XYR1(/M) stage includes the XYR1A solid sample plate. This plate can be detached from the stage to reveal the same mounting features present on the XYR1(/M) stage.

Motorized Rotation Mounts and Stages

Motorized Rotation Mounts and Stages with Central Clear Apertures
Item #	DDR25(/M)	PDR1C(/M)	PDR1(/M)	PDR1V(/M)	PDXR1(/M)
Click Photo to Enlarge
Features	Compatible with SM05 Lens Tubes, 16 mm Cage System, & 30 mm Cage System	Compatible with 16 mm Cage System	Compatible with SM05 Lens Tubes & 30 mm Cage System	Vacuum-Compatible; Also Compatible with SM05 Lens Tubes & 30 mm Cage System	Compatible with SM05 Lens Tubes & 30 mm Cage System
Additional Details

Motorized Rotation Mounts and Stages with Central Clear Apertures
Item #	K10CR1(/M)	PRM1Z8(/M)^a	DDR100(/M)	ELL14	HDR50(/M)
Click Photo to Enlarge
Features	Compatible with SM1 Lens Tubes & 30 mm Cage System		Compatible with SM1 Lens Tubes, 16 mm Cage System, 30 mm Cage System	Compatible with SM1 Lens Tubes, Open Frame Design for OEM Applications	Compatible with SM2 Lens Tubes
Additional Details

This stage is available in the KPRMTE(/M), which includes the PRMTZ8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.

Motorized Rotation Mounts and Stages with Tapped Platforms
Item #	PRMTZ8(/M)^a	ELL18(/M)^b
Click Photo to Enlarge
Features	Tapped Mounting Platform for Mounting Prisms or Other Optics	Tapped Mounting Platform, Open Frame Design for OEM Applications
Additional Details

This stage is available in the KPRM1E(/M), which includes the PRMT1Z8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.
This stage is available in the ELL18K(/M), which includes an interface board, mounting brackets, and connectors for PC control.

High-Precision Rotation Mount for Ø2.00" Optics

High-Precision Rotation Mount for Ø2.00in Optics

Zoom

Two Inch Rotation Mount Mechanical Drawing

Click for Details

Accepts Ø2" (Ø50.8 mm) Optics up to 0.48" (12.2 mm) Thick
360° Continuous Coarse Rotation
Direct Read 1° Graduations Engraved on Rotation Dial Face
±7° of Micrometer-Driven Fine Rotation when Locked
Vernier Scale with 5 arcmin Resolution
Compatible with our SM2 Lens Tubes and 60 mm Cage System
One SM2RR Retaining Ring Included
Bottom-Located 8-32 (M4) Tapped Hole for Post Mounting

The PRM2(/M) high-precision rotation mount for Ø2" optics combines 360° of continuous coarse manual rotation with precise, backlash-free micrometer adjustment. The SM2-threaded (2.035"-40) inner bore accepts Ø2" optics up to 0.48" (12.2 mm) thick as well as any of our SM2-threaded components. Optics are secured with one SM2RR retaining ring (included with each mount).

The rotation dial face features a laser-engraved scale marked at 1° increments and can be rotated manually using the knurled outer surface (see drawing to the right). The thumbscrew, located on the lower right side of the mount, locks the dial face and engages the micrometer for fine adjustment. When locked, the micrometer provides ±7° of rotation at approximately 2.4 arcmin per micrometer division. This rotation mount also features a 0.05" hex setscrew on both sides that can lock both the fine and coarse rotational movement. If replacement setscrews are needed, we offer SS4B025 brass setscrews, which use a 0.05" (1.3 mm) hex.

The PRM2(/M) is also compatible with our 60 mm cage system. The cage system can be mounted to the unit using ER cage assembly rods attached to the four 4-40 tapped holes located on the rotation dial face or the four 4-40 tapped holes located on the back side of the mount. The cage system attached to the back of the mount does not rotate.

Continuous Rotation Mount for Ø2" Optics

Continuous Rotation Mount for Ø2in Optics

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Mount Ø2" Optics up to 0.51" (13 mm) Thick
Compatible with SM2 Lens Tubes
One SM2RR Retaining Ring Included
Bottom-Located 8-32 (M4) Tapped Hole for Post Mounting

The RSP2(/M) Continuous Rotation Mount utilizes two precision bearings for smooth rotation. The aperture features internal SM2 (2.035"-40) threading and accepts Ø2" optics up to 0.51" (13 mm) thick as well as any SM2-threaded component. Secure the optic using the included SM2RR retaining ring.

The mount has a knurled edge for rotation. A 360° laser-engraved scale marked at 2° increments allows for precise, repeatable positioning and fine angular adjustment. A top-located setscrew can be tightened with a 5/64" (2.0 mm) hex key or balldriver to lock the rotation of the mount.

Continuous Rotation Mount for Ø2" Optics with Adjustable Zero

Continuous Rotation Mount for Ø2in Optics with Adjustable Zero

Zoom

This animation shows the movable scale of the RSP2D Mount being rotated to align with the fast axis of a wave plate.

Mount Ø2" Optics up to 0.54" (13.7 mm) Thick
Dial Face can be Rotated Independently of Mounted Optics
5 arcmin Vernier Scale
Compatible with SM2 Lens Tubes
One SM2RR Retaining Ring Included
Bottom-Located 8-32 (M4) Tapped Hole for Post Mounting

The RSP2D(/M) Ø2" Continuous Rotation Mount offers the same features as the RSP2 featured above but also incorporates a rotatable dial that can be used, for example, to align a wave plate's optical axis after mounting. Like the RSP2(/M) above, this mount utilizes two precision bearings for smooth, backlash-free rotation. The aperture is threaded with our internal SM2 threading (2.035"-40) and accepts Ø2" optics up to 0.54" (13.7 mm) thick. Secure the optic's position using the included SM2RR retaining ring. The SM2 threading also provides a means to connect SM2 lens tubes and other Thorlabs components to the mount.

This mount has a 360° laser-engraved scale marked at 2° increments to allow for precise, repeatable positioning and fine angular adjustment. The front dial scale can be unlocked and rotated using a 5/64" (2.0 mm) hex key so that the scale can be aligned to the axis of an optic for calibration purposes. A top-located setscrew can be tightened with a 5/64" (2.0 mm) hex key or balldriver to lock the rotation of the mount.

Nested Rotation Mount for Ø2" Optics

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Mount Ø2" Optics Up to 0.46" (11.7 mm) Thick
Optic Carriage (LM2-A) and Mounting Ring (LM2-B or LM2-B/M) Sold Separately
Rotating Optic Carriage is Interchangeable for Quick Swapping
SM2-Threaded Optic Bore in Rotating Optic Carriage
Post Mountable via 8-32 (M4) Tap
Laser Engraved Scale with Graduations Every 2°, Labeled Every 20°

The LM2-A optic carriage can be nested inside of the LM2-B (LM2-B/M) mounting ring and offers 360° of continuous rotation for Ø2" optics. The optic bore of each carriage features internal SM2 (2.035"-40) threading and can hold an optic up to 0.46" (11.7 mm) thick with the included SM2RR retaining ring an optic in an SM2-threaded housing. The carriage attaches to the main body of the mount using a thumbscrew. To remove the carriage from the mount, simply loosen the thumbscrew. Extra LM2-A interchangeable rotating carriages are available to allow optics to be swapped out quickly at easily.

Each carriage has a 360° laser-engraved scale marked at 2° increments for precise, repeatable positioning. The top-located thumbscrew can be tightened to lock the rotation of the optic carriage and, along with the double bore on the mount, maintains a stable, three-point contact to hold the optic carriage. When the LM2-A is properly fastened in the LM2-B by the thumbscrew, the optic axis is 1.45" (36.8 mm for the LM2-B/M) above the top of the post.

Ø2" Kinematic Rotation Mount

Zoom

Combines Kinematic Angular Adjustment with Rotation in One Mount
Two 1/4"-80 Lockable Stainless Steel Adjusters with Removable Knobs and Brass Bushings for Smooth Adjustments
Four #8 (M4) Counterbored Mounting Holes Allow Left-Handed or Right-Handed Orientations
Engraved Rotation Scale with 2° Graduations Provides 360° Rotation
SM2-Threaded (2.035"-40) Rotation Ring with Locking Screw

The KS2RS is designed to hold Ø2" (50.8 mm) optics in situations where it is necessary to control the tip/tilt position as well as the rotation of the optic. This mount is ideal for polarization optics such as linear polarizers or wave plates. In addition, our mounted dove prisms with SM2 threading may also be mounted in the KS2RS to change the orientation of the rotated image. The KS2RS features an SM2-threaded bore capable of mounting Ø2" optics up to 0.47" (12.0 mm) thick using the included SM2RR retaining ring. Additionally, SM2 lens tubes may be threaded onto the mount to accomodate thicker optics.

Thorlabs' Kinematic Rotation Mounts combine the features of our Precision Kinematic Mirror Mounts and Manual Rotation Mounts, providing continuous 360° rotational adjustment and ±4° kinematic tip/tilt adjustment. These mounts are therefore ideal for holding optics with rotational asymmetry, such as polarization optics or round cylindrical lenses.

The rotation of the mount may be locked in position with a locking screw. The locking screw is activated using a 5/64" (2 mm) hex key. The kinematic adjustment is provided by two 1/4"-80 adjusters with brass bushings to provide smooth adjustment. Each adjuster may be locked with a locking screw using a 5/64" (2 mm) hex key.

Please note that while this mount is designed to hold Ø2" optics, the mount uses the same form factor as the KS3 Ø3" mirror mount in order to incorporate the rotation ring.

If higher adjustment resolution or control is desired, the 1/4"-80 adjusters used in these mounts can be switched with DAS110 or DM22 Differential Adjusters.

6-Axis Kinematic Mount for Ø2" Optics

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6-Axis kinematic mount usage. Note that while this animation shows the K6XS
mount for Ø1" optics, the operation of the K6X2 is analogous.

Six Adjustment Axes with Locks
- Kinematic Pitch/Yaw: ±2° at 3.6 mrad/rev
- X and Y Translation: ±2 mm at 254 µm/rev
- Z Translation^a: ±0.13" (±3.2 mm) at 318 µm/rev
- Continuous 360° Roll Control with 1° Graduations
Independent X, Y, and Roll Adjustment
SM2-Threaded Bore for Ø2" (50 mm) Optics up to 0.53" (13.4 mm) Thick
Six #8 (M4) Counterbores for Post Mounting

The K6X2 6-Axis Kinematic Optic Mount is designed as a general-purpose, high-precision positioner. The optic cell can be translated along or rotated about 6 axes, and each axis has a locking screw for stability. The mount uses 1/4"-80 adjuster screws for pitch, yaw, and z-axis adjustment, and 3/16"-100 adjuster screws for x- and y-axis adjustment.

The translating cell has SM2 (2.035"-40) threading for attaching Ø2" lens tubes or mounting Ø2" (50 mm) optics up to 0.53" (13.4 mm) thick using the included SM2RR Retaining Ring, which can be tightened using an SPW604 Spanner Wrench (sold separately). In testing, the X and Y axes of the K6X2 caused less than ±35 µm of crosstalk. If higher adjustment resolution is desired for pitch, yaw, or z-translation, the three 1/4"-80 adjusters can be replaced with DAS110 Differential Adjusters.

For more information on our 6-axis kinematic mounts, including versions for Ø1/2" and Ø1" optics, see our full web presentation.

Z-axis translation is accomplished by turning all three tip/tilt adjusters equally in the same direction.

60 mm Cage Rotation Mount

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Mounts Ø2" (Ø50.8 mm) Optics or SM2-Threaded Components
Ø48.3 mm Clear Aperture
360° of Continuous Rotation
1° Engraved Graduations on Dial, Labeled Every 10°
Setscrew Locking Mechanism
SM2-Compatible Rotation Carriage
8-32 (M4 x 0.7) Hole for Post Mounting

The LCRM2A(/M) Rotation Mount is designed to mount Ø2" (50.8 mm) optics up to 0.52" (13.2 mm) thick in an SM2-threaded (2.035"-40) rotation carriage. The optic is secured using the included SM2RR retaining ring (the SPW604 spanner wrench is ideal for tightening this retaining ring). For thicker optics, any of our SM2 series of lens tubes can be threaded into the carriage. The smooth rotation mechanism allows for precise positioning of the rotation carriage. The mount is compatible with the 60 mm cage system and can be mounted on a Ø1/2" optical post using the 8-32 (M4 x 0.7) tapped mounting hole on the bottom side of the rotation mount.

60 mm Cage Rotation Mount, ±8° Fine Rotation Adjustment

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The LCP16R2 rotation mount in a 60 mm cage system with two LCP34 cage plates.

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This mount offers 360° of coarse rotation via the rotation ring and ±8° of fine rotation via the threaded adjuster. The coarse and fine rotation are independent of each other and both positions can be locked using the respective 5/64" (2 mm) hex locking screws.

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The LCP16R2 mount includes an LCP16RP2 SM2-threaded rotation ring that can be removed (left) and replaced with an LCP16RP1 SM1-threaded rotation ring (right).

Mount Ø2" (Ø50.8 mm) Optics or SM2-Threaded Components
Ø1.90" (Ø48.3 mm) Clear Aperture
±8° of Fine Rotation; 360° of Manual Coarse Rotation
1° Engraved Graduations, Labeled Every 2° up to ±8°
Setscrew Locking Mechanism
Suitable for Cantilevered Loads up to 0.5 ft-lbs (0.68 N•m) Torque
Included LCP16RP2 Removable Rotation Ring
One 8-32 (M4 x 0.7) Hole for Post Mounting

Thorlabs' LCP16R2(/M) 60 mm Cage System Rotation Mount with SM2 Threads provides ±8° of fine and 360° of coarse rotation angle adjustment for SM2-threaded components integrated with a 60 mm cage system. A nylon-tipped setscrew secures the included LCP16RP2 rotation ring; this setscrew can be loosened using a 5/64" (2 mm) hex key to allow for 360° of manual rotation (see the image to the right). Once this screw is tightened, fine rotation adjustment is achieved via a 3/16"-100 threaded adjuster. A fine adjustment scale engraved on the top of the mount has graduations every 1° with a range of ±8°.

This mount features four through holes for ER cage rods that are compatible with Thorlabs' 60 mm cage system or cameras that use this hole pattern, such as our scientific CCD cameras. The removable rotation ring on the front of the mount has 0.40" (10.1 mm) deep internal SM2 (2.035"-40) threads, allowing Ø2" (Ø50.8 mm) optics, Ø2" lens tubes, or other externally SM2-threaded components to be integrated with the rotation mount. Internally C-mount threaded components, such as Thorlabs' USB C-Mount CCD, Quantalux^® sCMOS, or Kiralux™ CMOS cameras, can be attached to the rotation ring using an SM2A55 adapter.

Users can switch out the included SM2-threaded LCP16RP2 rotation ring with the SM1-threaded LCP16RP1 rotation ring to integrate SM1-threaded components into the LCP16R2(/M) mount; see the image to the right. We also offer the LCP16RP2 rotation ring separately in case a replacement is needed. To switch the rotation ring in a mount, loosen the side-located setscrew using a 5/64" (2 mm) hex key and replace the rotation ring with the desired one.

We also have available an SM1-threaded 60 mm cage system rotation mount.

Swivel Mounts/Plates for 60 mm Cage Systems

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±90° Angular Displacement Between Two 60 mm Cage Plates
Platform with 0.93" (23.6 mm) Vertical Height Adjustment
Independently Lockable Plates and Mounting Platform
Generous Array of Mounting Holes on Platform

The LC1AR(/M) Swivel Mount is ideal for building spectrometers or other prism- and grating-based systems that require arbitrary angular alignment. The swivel plates are internally threaded for compatibility with our SM2 (2.035"-40) Series of Lens Tubes. In addition, the plates and mounting platform of the LC1AR(/M) mount are independently lockable.

The pedestal can rotate through a full 360° and provides 0.93" (23.6 mm) of vertical height adjustment. To aid in alignment, there is an engraved scale with 2° increments below the pedestal. The platform has an array of threaded holes, making it easy to mount a variety of optical elements, such as prisms and gratings, using our PM3(/M) or PM4(/M) clamping arms. See the drawing to the right for more details.

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous			Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°	Manual, 360° Continuous
Optic Mounting	Internally SM05-Threaded Carriage
Maximum Accepted Optic Thickness	0.23" (5.8 mm)	0.23" (5.8 mm)	0.26" (6.5 mm)	0.23" (5.9 mm)	0.24" (6.0 mm)	0.41" (10.4 mm)	0.29" (7.3 mm)
Post Mounting	4-40 (M3) Stud	8-32 (M4) Tap	None	8-32 (M4) Tap	None	Two Counterbores for 8-32 (M4) Cap Screws	Two Counterbores for 4-40 (M3) Cap Screws
Cage System Compatibility	N/A				Four Bores for ∅4 mm Cage Rods with 16 mm Spacing	N/A	N/A^c

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous					Manual, Continuous: 360°; Discrete: 15°	Manual, Continuous: 360°; Discrete: 22.5°	Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°
Optic Mounting	Internally SM1-Threaded Carriage
Maximum Accepted Optic Thickness	0.47" (11.9 mm)	0.34" (8.6 mm)	0.51" (12.9 mm)	0.25" (6.4 mm)	0.27" (6.8 mm)	0.50" (12.7 mm)	0.50" (12.7 mm)	0.50" (12.7 mm)
Post Mounting	8-32 (M4) Tap	N/A	8-32 (M4) Tap
Cage System Compatibility	N/A							Four 4-40 (M3) Taps on Rotation Dial with 30 mm Spacing

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous			Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°	Manual, 360° Continuous
Optic Mounting	Internal SM1 Threads in LM1-A	Internally SM1-Threaded Carriage	Double-Bore with Setscrew	Internally SM1-Threaded Carriage
Accepted Optic Thickness	Max: 0.37" (9.4 mm)	Max: 0.37" (9.4 mm)	Min: 0.31" (7.9 mm)	Max: 0.37" (9.4 mm)	Max: 0.47" (11.9 mm)	Max: 0.55" (14 mm)
Post Mounting	8-32 (M4) Tap in LM1-B	8-32 (M4) Tap			Six Counterbores for 8-32 (M4) Cap Screws
Cage System Compatibility	N/A	Four Bores for ∅6 mm Cage Rods with 30 mm Spacing			N/A

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous
Mounting Platform
Diameter	Ø1.00" (Ø25.4 mm)	Ø1.00" (Ø25.4 mm)	Ø1.40" (Ø35.6 mm)	Ø2.07" (Ø52.8 mm)	Ø4.29" (Ø109.0 mm)	Ø2.00" (Ø50.8 mm)
Height	0.67" (17.0 mm)	0.75" (19.1 mm)	0.51" (13.1 mm)	0.63" (16.1 mm)	0.70" (17.8 mm)	1.00" (25.4 mm)
Taps	Six 4-40 (M3) One 1/4"-20 (M6)	One 8-32 (M4) Eight 4-40 (M3)	Four 4-40 (M3) One 8-32 (M4)	Four 8-32 (M4) One 1/4"-20 (M6)	Eight 6-32 (M4) Sixteen 8-32 (M4) Thirteen 1/4"-20 (M6)	Four 6-32 (M4) Four 8-32 (M4) Five 1/4"-20 (M6)
Additional Holes	Two Ø0.13" (Ø3.2 mm) Holes for FiberBench Accessories	-	Four Clearance Holes for 4-40 (M3) Cap Screws	-	-	-
Platform Adapter Plate(s)	-	-	-	-	-	-
Base
Dimensions	1.50" x 1.50" (38.1 x 38.1 mm)	1.50" x 1.50" (38.1 x 38.1 mm)	1.78" x 1.40" (45.2 x 35.6 mm)	2.45" x 2.45" (62.2 x 62.2 mm)	4.65" x 4.65" (118.1 x 118.1 mm)	2.55" x 2.55" (64.8 x 64.8 mm)
Mounting Holes	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 4-40 (M3) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Counterbores for 1/4"-20 (M6) Cap Screws
Side Taps for Vertical Mounting	-	-	One 4-40 (M3)	One 8-32 (M4)	Three 8-32 (M4)	-
Cage System Compatibility	N/A

Rotation Drive Mechanism and Adjustment Range	Manual: 360° Continuous; Fine: Adjuster Screw, ±5°	Manual: 360° Continuous; Fine: Adjuster Screw, ±5°	Manual: 360° Continuous; Fine: Micrometer, ±5°	Worm Gear, 360° Continuous	Manual, 360° Continuous with 1/2" (13 mm) Linear Travel Along X and Y Axes with Micrometer
Mounting Platform
Diameter	Ø2.21" (Ø56.0 mm)	Ø3.19" (Ø81.0 mm)	Ø2.70" (Ø68.6 mm)	Ø1.70" (Ø43.2 mm)	Ø4.18" (Ø106.0 mm)	Ø4.04" (Ø102.5 mm)
Height	On Breadboard: 0.91" (23.0 mm)^a Dovetail Stacked: 0.83" (21.0 mm)	On Breadboard: 0.91" (23.0 mm)^a Dovetail Stacked: 0.83" (21.1 mm)	1.00" (25.3 mm)	1.00" (25.4 mm)	1.00" (25.4 mm)	1.65" (41.8 mm)
Taps	Thirteen 1/4"-20 (M6) Four 8-32 (M4) Four 6-32 (M4)	Thirteen 1/4"-20 (M6) Four 8-32 (M4) Four 6-32 (M4)	Four 4-40 (M3) Ten 6-32 (M4) Six 1/4"-20 (M6)	Four 4-40 (M3) Eight 6-32 (M4) Four 8-32 (M4)	Eight 4-40 (M3) Twelve 8-32 (M4) Sixteen 1/4"-20 (M6)	-^b
Additional Holes	-	-	Ø0.94" (Ø23.9 mm) Clear Aperture with SM1 Threading	-	Ø0.90" (Ø22.9 mm) Clear Aperture with SM1 Threading	-^b
Platform Adapter Plate(s)	-	-	PR01A(/M) CRA30(/M)	CR1A(/M)	XYR1A	-^b
Base
Dimensions	3.35" x 2.52" (85.0 mm x 63.9 mm)	4.33" x 3.58" (110.0 mm x 91.0 mm)	2.75" x 3.50" (69.9 x 88.9 mm)	2.76" x 2.10" (70.1 x 53.4 mm)	5.50" x 4.42" (139.7 x 112.3 mm) (Not Including Micrometers)
Mounting Holes	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Two Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws
Side Taps for Vertical Mounting	-	-	Two 1/4"-20 (M6)	-	-
Cage System Compatibility	-	N/A	Four 4-40 Taps on Top Surface for 30 mm Cage System	N/A	Four 4-40 Taps on Top Surface for 30 mm Cage System Four 4-40 Taps on Top Surface for 60 mm Cage System Four 4-40 Taps on Bottom Surface for 60 mm Cage System	-^b

Motor Type	Brushless DC Servo	Piezo Inertia Drive
Rotation Adjustment Range	360° Continuous
Rotating Platform/Carriage
Diameter	1.14" (29.0 mm)	1.10" (28.0 mm)	1.34" (34.0 mm)	1.96" (49.7 mm)
Height	1.12" (28.5 mm)	0.71" (18.0 mm)		0.91" (23.0 mm)
Threaded Mounting Holes	Four 4-40 with 16 mm Spacing	Four 8-32 (M4 x 0.7), Four 4-40 with 16 mm Spacing	Four 8-32 (M4 x 0.7)	Four 8-32 (M4 x 0.7), Four 4-40 with 30 mm Spacing Four 2-56 (M2 x 0.4)
Center Aperture	SM05 Internal Threads, 1.2" (28.5 mm) Deep	Ø4.9 mm Clear Aperture with 1/4"-20 (M6 x 1.0) Internal Threads, Thru	Ø9.0 mm Clear Aperture with SM05 Internal Threads, 2.5 mm Deep	Ø9.0 mm Clear Aperture with SM05 Internal Threads, 3.5 mm Deep
Speed (Max)	1800°/s	100°/s	20°/s	30°/s
Base
Dimensions	2.19" x 2.19" (55.6 mm x 55.6 mm)	1.18" x 1.18" (30 mm x 30 mm)	1.57" x 1.57" (40.0 mm x 40.0 mm)	2.20" x 2.20" (56.0 mm x 56.0 mm)
Bottom Surface Mounting Features	-	Two #2 (M2) Slots	Two 8-32 (M4 x 0.7) Holes	Two #8 (M4) Counterbores Two 8-32 (M4 x 0.7) Holes
Side Holes for Vertical Mounting	Four 8-32 (M4 x 0.7) Eight 4-40	Three 8-32 (M4 x 0.7)	One 8-32 (M4 x 0.7), Two Sides	One 8-32 (M4 x 0.7)
Cage System Compatibility	Four 4-40 Holes on Back Side with 16 mm Spacing, Four 4-40 Taps on Front Side with 30 mm Spacing	-	Ø6 mm Holes for ER Cage Rods with 30 mm Spacing	Four 4-40 Taps on Rotating Platform with 30 mm Spacing

Motor Type	2 Phase Stepper Motor with Worm Gear	DC Servo	Brushless DC Servo	Piezo Resonant Motor	2 Phase Stepper Motor with Worm Gear
Rotation Adjustment Range	360° Continuous
Rotating Platform/Carriage
Diameter	1.81" (46.0 mm)	1.97" (50.0 mm)	4.37" (111.0 mm)	-	3.86" (98.0 mm)
Height	0.84" (21.5 mm)	0.91" (23.0 mm)	1.57" (39.9 mm)	0.59" (15.1 mm)	1.73" (44.0 mm)
Threaded Mounting Holes	Six 4-40 (M3)	Four 6-32 (M4), Four 8-32 (M4), Four 4-40 with 30 mm Spacing	Eight 8-32 (M4), Four 1/4"-20 (M6), Four 4-40 with 16 mm Spacing, Four 4-40 with 30 mm Spacing	-	Four 8-32 (M4)
Center Aperture	SM1 Internal Threads, 0.84" (21.5 mm) Deep	SM1 Internal Threads, 0.91" (23.0 mm) Deep	SM1 Internal Threads, 0.82" (21.0 mm) Deep	SM1 Internal Threads, 0.58" (14.7 mm) Deep	Ø50.0 mm Clear Aperture with SM1 Internal Threads, 6.9 mm Deep
Speed (Max)	10°/s	25°/s	1080°/s	430°/s	50°/s
Platform Adapter Plate(s)	K10CR1A2(/M)	PRM1SP1(/M)	NR360SP9(/M) NR360SP4(/M)	-	NR360SP9(/M) NR360SP8 NR360SP4(/M)
Base
Dimensions	4.21" x 2.60" (107.0 mm x 66.0 mm)	5.18" x 3.26" (131.5 mm x 82.8 mm)	4.53" x 4.53" (115 mm x 115 mm)	2.60" x 3.25" (66.0 mm x 82.5 mm)	7.46" x 4.55" (189.4 mm x 115.5 mm)
Stage Adapter Plates	K10CR1A1 K10CR1A3	PRM1SP2 PRM1SP3	-	-	NR360SP2(/M) NR360SP5(/M)
Bottom Surface Mounting Holes	-	Two 1/4" (M6) Counterbores	Four 1/4" (M6) Clearance Holes	-	Four 1/4" (M6) Counterbores
Side Holes for Vertical Mounting	Three 8-32 (M4)	Four 8-32 (M4)	Eight 1/4"-20 (M6)	-	Six 1/4"-20 (M6)
Cage System Compatibility	Four 4-40 Holes on Each Side with 30 mm Spacing	-	Four 4-40 Holes on Back Side with 30 mm Spacing	60 mm Cage using Four Ø0.12" (3.0 mm) Holes for 4-40 Screws, 30 mm Cage using SR025 Cage Rods to Adapt to ER Cage Rods	-