Vacuum-Compatible Table Clamps


  • Secure Optomechanical Assemblies to Tables and Breadboards
  • Vacuum-Compatible to >10-6 Torr
  • Solid One-Piece Construction

CL2V

Heavy-Duty Variable Height Clamp, 1/4"-20 Tapped

CL3V

Compact Variable Height Clamp, 1/4"-20 Tapped

CL4V

Table Clamp for Tight Space Applications

CL5AV

L-Shaped, Rounded Tip Table Clamp

CL6V

RLA Series Optical Rail Table Clamp

CL8V

For Ø1" and
Ø1.5" Pedestal Posts

Related Items


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Additional Vacuum-Compatible Components

Many of our other optomechanical components can be special ordered for vacuum use. Contact techsales@thorlabs.com for details.

Options

  • Vacuum-Compatible Versions of our Table Clamps
  • CL2V: Heavy-Duty Clamp with Adjustable Height
    CL3V: Compact Clamp with Adjustable Height
  • CL4V: Compact Clamp for Tight Spaces
  • CL5AV: General-Purpose Clamp
  • CL6V: Wedged for Use with Dovetail Optical Rails
  • CL8V: Table Clamp for Ø1" and Ø1.5" Pedestal Posts

Thorlabs' Vacuum-Compatible Table Clamps are useful when constructing optomechanical assemblies. The design of our clamps helps to reduce an assembly's setup time by adapting complex layouts to any mounting hole pattern. Each clamp is suitable for securing bases and other optomechanical components with thicknesses in the ranges specified in the table below. These clamps are used with 1/4"-20 (M6) cap screws and washers, vacuum-compatible versions of which are available here. All clamps are sold in packs of 5.

Vacuum Compatibility Information
Our vacuum-compatible optomechanics are wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. They are compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table below). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

We also offer other optomechanical components which may be used in vacuum applications, such as Ø1/2" and Ø1" Post Systems. We also offer Unanodized Aluminum Breadboards, which may be used in vacuum applications after undergoing cleaning and processing by the end user.

Specs Item #
CL2V(/M) CL3V(/M) CL4V CL5AV CL6V CL8V
Component Thickness Minimum Variablea Variablea 0.02" (0.5 mm) 0" 0" 0"
Maximum 0.25" (6.4 mm) 0.80" (20.3 mm) 0.25" (6.4 mm) 0.30" (7.6 mm)
Vacuum Specifications
Vacuum Compatibility as Packagedb >10-6 Torr
Materials 6061-T6 Aluminum
Preparation and Packaging Wiped with Alcohol and Double Vacuum-Bagged
Aluminum Outgassing Rate at 20 °C 7.6 x 10-9 Torr-Liters/s/cm2
  • The thickness of components that can be used with this clamp depends on the length of the screws used to secure the clamp.
  • 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.

Insights into Best Lab Practices

Scroll down to read about a few things we consider when setting up lab equipment.

  • Clamping Forks: Tip for Maximizing the Holding Force
  • Optical Tables: Clamping Forks and Distortion of the Table's Surface

Click here for more insights into lab practices we follow.

 

Clamping Forks: Tip for Maximizing the Holding Force

Clamping force applied by the CL2 clamping fork
Click to Enlarge

Figure 2: More than half the total applied force (FTotal) holds the object, since L1 > L2. The height of the left leg of this CL2 clamp is variable to compensate for the object's height. This allows the clamp's top surface and the mounting surface to be made parallel.**
Clamping force applied by the CLA5 clamping fork
Click to Enlarge

Figure 1: Less than half the total applied force (FTotal) holds the object, since L1 < L2. The clamp illustrated above is the CL5A.

Clamped objects can be fairly easy to move when the torqued screw in the clamp's slot is positioned too far from the object. Correct positioning of the screw protects clamped objects from being knocked out of position.

To maximize the clamping force, position the screw as close as possible to the object.**

This works since clamps like CL5A and CL2 (Figures 1 and 2, respectively) divide the torqued screw's applied force (FTotal) between two points.

Clamping force F2 is applied to the object. The value of F2 is a percentage of FTotal and depends on L1 and L2, as described below. The remainder (F1) of the total force is applied through the opposite end of the clamp.

The following equations can be used to calculate the two applied forces.

Force Applied to
Object:
Force Applied to
Other Contact Point:

These equations show that the clamping force on the object increases as the distance between the object and screw decreases. The force supplied by the torqued screw is evenly divided between F1 and F2 when L1 and L2 are equal.

**Note that maximizing the clamping force also requires both the top surface of the clamp and the area it contacts on the object to be parallel with the mounting surface, as depicted in Figures 1 and 2.

If the tangent at the interface between the clamp and object is not parallel to the mounting surface, the force applied to the object will be divided between pressing it into and pushing it across the mounting surface. The force directed along the mounting surface may, or may not, be sufficient to translate the object.

To accommodate different object heights, clamps like the CL2 have one threaded, variable-length leg, which is shown on the left in Figure 2. The number of threads between the clamp and mounting surface should be adjusted to compensate for the height of the object and to keep the clamp's top surface level with the table.   

Date of Last Edit: Dec. 4, 2019

 

Optical Tables: Clamping Forks and Distortion of the Table's Surface

Optical table composite construction
Click to Enlarge

Figure 3: The construction of a Nexus table / breadboard includes a (1) top skin, (2) bottom skin, (3) side finishing trim, (4) side panels, and (5) honeycomb core. The stainless steel top and bottom skins are 5 mm thick.

Clamping forks are more rigid than the mounting surface of composite optical tables. It might be expected that the spine of the clamping fork would bend with the force exerted by the screw as the torque is increased. Instead, the screw will pull the skin of the table up and out of flat before the clamping fork deforms. Due to this, clamping forks should be used with care when securing components to optical tables. Clamping arms, which are discussed in the following, are alternatives to clamping forks that are less likely to deform the table's mounting surface.

Optical Table Construction
Optical tables and breadboards with composite construction (Figure 3) are designed to be rigid while providing vibration damping. The 5 mm thick, stainless steel top skin is manufactured to be flat, but a localized force can deform it. When the top skin is deformed, optical components will not sit flat, and optical system alignment and performance can be negatively affected.

Clamping Forks
Standard clamping forks are installed with one edge placed on the table's surface and the opposite edge on the object (Figure 4). Between these two edges, there is clearance between the bottom of the clamp and the surface of the table. This bridge makes it possible to use a single screw to both secure the clamp to the table and exert a holding force on the object.

When the clamp is secured by torqueing the screw, the screw pulls up on the top skin of the table (Figure 5).

As the torque on the screw increases, the top skin of the table rises. Not only does pulling up on the table surface risk permanently damaging the table, this can also disturb the alignment of the optical component the clamp is being used to secure. By lifting the table's skin, the mounting surface under the clamped object tilts.

Clamping arms do not create a bridge over the mounting surface
Click to Enlarge

Figure 6: The POLARIS-CA1/M clamping arm has a slot that accepts a mounting screw, a separate screw that applies a clamping force to an installed post, and identical top and bottom surfaces. Since a nearly continuous track around the surface of the clamping arm is in contact with the mounting surface, clamping arms cause negligible bridging effects.
Clamping fork pulling up on and deforming mounting surface of optical table
Click to Enlarge

Figure 5: Torqueing the screw creates a force that pulls up on the table's top skin. The lifted skin tilts the mounting surface and can induce angular deviation of the object. This effect is exaggerated in the above image for illustrative purposes.
Bridge created by clamping fork
Click to Enlarge

Figure 4: A standard clamping fork, such as the CL5A, contacts the table along only one edge. The opposite edge is in contact with the object to be secured. A bridge forms between the two. The screw that applies the clamping force is not shown.

Clamping Arms
Clamping arms, such as the POLARIS-CA1/M, shown in Figure 6, are designed to secure a post while minimally deforming the mounting surface.

The clamping arm in Figure 6 differs from clamping forks in two significant ways. One is the surface area that makes contact with the optical table, which is highlighted in red, and the other is the method used to secure the post.

The area in contact with the optical table makes a nearly continuous loop around the base of the clamp. The contact area is flat and flush with the table when the clamp is installed. The only break in the loop is a narrow slot in the vise used to grip the post. 

This design uses two screws, instead of the clamping fork's single screw. One screw (not shown) secures the clamp to the table, and the other (indicated) is tightened to grip the post. Since one screw is not required to perform both tasks, it is not necessary for this clamping arm to form a bridge between the clamped object and the optical table.

Although the contact area is a loop, and not a solid surface, this clamp causes negligible distortion of the mounting surface. This is due to the open area inside the contact surface being narrow and surrounded by the sides of the clamp, which resist the force pulling up on the table.

Date of Last Edit: Dec. 4, 2019


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Heavy-Duty Vacuum-Compatible Table Clamp with Adjustable Height

CL2 Cross Section
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CL2V(/M) Cross-Sectional View

The CL2V(/M) heavy-duty table clamp is a vacuum-compatible version of our CL2(/M). It uses two cap screws: one in the 1/4"-20 (M6) tapped hole to adapt the clamp to virtually any height and another in the slotted hole to secure the clamp to the table. The extra-long design increases the force exerted on the optomechanic being held.

The thickness of optomechanical components that can be used with the CL2V(/M) clamp depends on the length of the screws used to secure the clamp.

The CL2V(/M) is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL2V(/M) is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
CL2V-P5 Support Documentation
CL2V-P5Customer Inspired! Vacuum-Compatible Heavy-Duty Variable Height Clamp, 1/4"-20 Tapped, 5 Pack
$96.54
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+1 Qty Docs Part Number - Metric Price Available
CL2V/M-P5 Support Documentation
CL2V/M-P5Customer Inspired! Vacuum-Compatible Heavy-Duty Variable Height Clamp, M6 Tapped, 5 Pack
$96.54
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Compact Vacuum-Compatible Table Clamp with Adjustable Height

CL3V Clamping a Breadboard
Click for Details
View Imperial Product List
Item #QtyDescription
Imperial Product List
CL3V-P51Vacuum-Compatible Compact Variable Height Clamp, 1/4"-20 Tapped, 5 Pack
SH25S038V21/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 3/8" Long, 5 Pack
MB4U1Unanodized Aluminum Breadboard, 4" x 4" x 1/2", 1/4"-20 Taps
W25S050V11/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
View Metric Product List
Item #QtyDescription
CL3V/M-P51Vacuum-Compatible Compact Variable Height Clamp, M6 Tapped, 5 Pack
SH6MS102M6 x 1.0 Stainless Steel Cap Screw, 10 mm Long, 25 Pack
MB1015U/M1Unanodized Aluminum Breadboard, 100 mm x 150 mm x 12.7 mm, M6 Taps
W25S050V11/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
CL3V Clamp Holding an
Unanodized Aluminum Breadboard
CL3 Cross Section
Click Details

CL3V(/M) Cross-Sectional View

The CL3V(/M) table clamp is a vacuum-compatible version of our CL3(/M). It uses two cap screws: one in the 1/4"-20 (M6) tapped hole to adapt the clamp to virtually any height and another in the slotted hole to secure the clamp to the table. Its compact design reduces the footprint of the clamp relative to the CL2(/M).

The thickness of optomechanical components that can be used with the CL3V(/M) clamp depends on the length of the screws used to secure the clamp.

The CL3V(/M) is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL3V(/M) is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
CL3V-P5 Support Documentation
CL3V-P5Customer Inspired! Vacuum-Compatible Compact Variable Height Clamp, 1/4"-20 Tapped, 5 Pack
$101.27
Today
+1 Qty Docs Part Number - Metric Price Available
CL3V/M-P5 Support Documentation
CL3V/M-P5Customer Inspired! Vacuum-Compatible Compact Variable Height Clamp, M6 Tapped, 5 Pack
$101.27
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Compact Vacuum-Compatible Table Clamp for Tight Spaces

CL4 Cross Section
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CL4V Cross-Sectional View

The CL4V table clamp is a vacuum-compatible version of the CL4. At 1.38" long and 0.63" wide, it is designed for situations where table space is at a premium. It requires one cap screw and washer to secure.

This clamp can be used with optomechanical components with a thickness up to 0.25".

The CL4V is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL4V is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CL4V-P5 Support Documentation
CL4V-P5Customer Inspired! Vacuum-Compatible Table Clamp, Tight Space Applications, 5 Pack
$57.41
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General-Purpose Vacuum-Compatible Table Clamp

CL5AV Clamping a Base
Click for Details
View Imperial Product List
Item #QtyDescription
CL5AV-P51Vacuum-Compatible Table Clamp, L-Shape, Rounded Lip, 5 Pack
TR3V1Ø1/2" Vacuum-Compatible Optical Post, 8-32 Setscrew, 1/4"-20 Tap, L = 3"
SH25S038V21/4"-20 Vacuum-Compatible Vented Cap Screw, 316 Stainless Steel, 3/8" Long, 5 Pack
BA2V1Mounting Base, 2" x 3" x 3/8", Vacuum Compatible
W25S050V11/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
View Metric Product List
Item #QtyDescription
CL5AV-P51Vacuum-Compatible Table Clamp, L-Shape, Rounded Lip, 5 Pack
TR75V/M1Ø12.7 mm Vacuum-Compatible Optical Post, M4 Setscrew, M6 Tap, L = 75 mm
BA2V/M1Mounting Base, 50 mm x 75 mm x 10 mm, Vacuum Compatible
SH6MS102M6 x 1.0 Stainless Steel Cap Screw, 10 mm Long, 25 Pack
W25S050V11/4" (M6) Vacuum-Compatible Washer, 316 Stainless Steel, 25 Pack
CL5AV Clamp Holding Down a BA2V 3/8" Thick Base
CL5 Cross Section
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CL5AV Cross-Sectional View

The CL5AV table clamp is a vacuum-compatible version of our CL5A. It has a curved lip that allows the clamp to be used with components up to 0.80" thick. At higher clamping angles, the rounded edge remains in contact with the top of the component, rather than pushing against the corner. This maintains a downward force and prevents unwanted horizontal movement on the table. In addition, the bottom of the clamp has a rounded edge with a relief cut to allow for sturdier contact between the clamp and optical table, especially when the clamp is used at a high angle.

The CL5AV is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL5AV is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CL5AV-P5 Support Documentation
CL5AV-P5Customer Inspired! Vacuum-Compatible Table Clamp, L-Shape, Rounded Lip, 5 Pack
$54.35
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Vacuum-Compatible Table Clamp for Construction Rails

CL5 Cross Section
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CL6V Cross-Sectional View

The CL6V clamp features a wedged tip that is specifically designed to fit our dovetail optical rails, allowing a rail to be secured along any direction on a breadboard or optical table. The low-profile clamp has the same height as a dovetail rail, although its presence can restrict the placement of rail carriers. Please note that while the CL6V clamp is designed for use with the dovetail optical rails, that the rails themselves are not vacuum compatible.The CL6 clamp can be used with optomechanical components up to 0.25" thick.

The CL6V is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL6V is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CL6V-P5 Support Documentation
CL6V-P5Customer Inspired! Vacuum-Compatible Table Clamp, RLA Series Optical Rails, 5 Pack
$60.59
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Vacuum-Compatible Table Clamp for Ø1" and Ø1.5" Pedestal Posts

CL8 Cross Section
Click to Enlarge

CL8V Cross-Sectional View

The CL8V pedestal post table clamp is a vacuum-compatible veresion of the CL8. It is designed for use with our Ø1" and Ø1.5" pedestal posts. Its V-shaped tip provides two-point contact with the perimeter of the post and its rounded edge increases the contact area along the optical table or breadboard. It requires one cap screw and washer to secure. Please note that while the CL8V clamp is designed for use with the Ø1" and Ø1.5" pedestal posts, that the posts themselves are not vacuum compatible.

The CL8V clamp can be used with optomechanical components up to 0.30" thick.

The CL8V is wiped with alcohol and prepared for vacuum applications before packaging in a cleanroom environment. It is compatible directly out of the packaging with vacuum environments down to 10-6 Torr. With additional cleaning and processing, it can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table in the Overview tab). The material properties of the aluminum and the cleaning methods completed by the end user should be used to determine the appropriateness of these products and materials in a specific vacuum system.

The CL8V is sold in packs of 5.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
CL8V-P5 Support Documentation
CL8V-P5Customer Inspired! Vacuum-Compatible Ø1" and Ø1.5" Pedestal Post Table Clamp, 5 Pack
$68.24
Today