Ø1.5" Damped Posts

  • Dynamically Damped Ø1.5" Post Reduces Mechanical Vibrations
  • Nickel-Plated Steel with a Matte Finish
  • Permanent Mounting Base with Four 1/4" (M6) Counterbores

HeNe Laser in C1503
V-Mount on DP14A Post

Application idea

Four 1/4" (M6) Counterbores for Mounting





Related Items

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DP14A Periscope
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View Imperial Product List
Item #QtyDescription
DP14A1Ø1.5" Dynamically Damped Post, 14" Long
C15112Ø1.5" Post Mounting Clamp, 2.50" x 2.50"
POLARIS-K1E2Polaris® Ø1" Mirror Mount, 3 Adjusters, Monolithic Optic Retention
View Metric Product List
Item #QtyDescription
DP14A/M1Ø1.5" Dynamically Damped Post, 14" Long, Metric
C1511/M2Ø1.5" Post Mounting Clamp, 63.5 mm x 63.5 mm, Metric
POLARIS-K1E2Polaris® Ø1" Mirror Mount, 3 Adjusters, Monolithic Optic Retention
Periscope Constructed from a DP14A Damped Post, C1511 Post Clamps, and POLARIS-K1E Mirror Mounts
DP14A Top Cap
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Damped Posts Feature an Engraved Top Cap Indicating the Item # as well as a 1/4"-20 (M6) Tapped Hole


  • Ø1.5" 1026 DOM Carbon Steel Posts Designed to Reduce Vibrations
  • Lead-Free Damping Weight Design for Shorter Damping Times Compared to Solid Stainless Steel Posts
  • 8", 10", 12", and 14" Long Versions Available
  • Nickel-Plated Steel with Matte Finish for Long Life
  • Permanent Mounting Base with Four 1/4" (M6) Counterbores

These Dynamically Damped Ø1.5" Mounting Posts offer a vibration-limiting alternative to long lengths of Ø1.5" solid steel posts. Damped posts are ideal for applications where mechanical vibrations must be limited, such as beam steering and imaging. Ring down testing was performed to compare the damping times for damped carbon steel and solid stainless steel posts (see the Ring Down Test tab for a summary of the test results).

Damped posts are available in four lengths: 8" (203.2 mm), 10" (254.0 mm), 12" (304.8 mm), and 14" (355.6 mm). The damped posts are fabricated from steel with a nickel-plated matte finish and utilize internal damping weights containing no lead. Using an engineered passive vibration dampening design, an internal suspension system allows weights inside the post to move independently from the post's outer body, thus allowing vibrational energy to quickly be absorbed and dissipated. On imperial versions, the permanently attached mounting base has four 1/4" counterbores for breadboards with a 1.00" hole spacing, while the metric versions have M6 counterbores for breadboards with a 25.0 mm hole spacing. The top cap is engraved with the part number for identification. The posts also feature a top-located 1/4"-20 (M6) tapped hole to allow components to be secured to the top of the post.

Item # DP8A(/M) DP10A(/M) DP12A(/M) DP14A(/M)
Damping Timea 20 ms 47 ms 61 ms 73 ms
Resonant Frequency (Theoretical) 780 Hz 435 Hz 300 Hz ~200 Hz
Length 8" (203.2 mm) 10" (254.0 mm) 12" (304.8 mm) 14" (355.6 mm)
Weight 1.56 kg (3.44 lbs) 1.91 kg (4.21 lbs) 2.14 kg (4.72 lbs) 2.4 kg (5.3 lbs)
Top-Located Tapped Hole 1/4"-20 (M6); 0.33" (8.4 mm) Deep
Mounting Permanent Base with Four 1/4" (M6) Counterbores for Breadboards with 1.00" (25.0 mm) Hole Spacing
  • The post was struck with a 13 N force near the top of the post and the damping time (time for vibration amplitude to decrease to 1% of the initial value) was measured. Please see the Ring Down Test tab for details on the testing procedures and results.

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Initial Setup for Ring Down Test of DP10A Damped Post

Ring Down Test

A ring down test is performed on our damped and standard Ø1.5" posts to quantify the time needed to dampen vibrations to a minimum. To do this, a rig is set up (shown in the image to the right) that is designed to strike the test post with approximately 13 N of force (determined by measuring the peak force using a force gauge) by releasing a steel-ball-tipped lever arm that is held at a pre-determined height using a pin. A piezoelectric accelerometer, mounted flush to the top of the test post and aligned with the strike point of the lever arm, measures and records the acceleration of the post due to vibrations as a voltage signal. Because loads mounted to the post increase its vibration damping ability, no additional load is added during testing. Therefore, the results presented below represent the worst-case scenario for vibration damping. 

In each set of test results shown below, both damped and standard posts are tested to compare the damping time (time it takes to reduce the amplitude of vibrations by 99%). For all post lengths tested, the damped posts dissipate the vibrational energy in a significantly shorter time frame than a standard post. See below for graphs from individual test runs.

Ring Down Test Summary (Average Over 5 Tests)
Post Length Damping Time (Damped Posts)a Damping Time (Standard Posts)a
8" (203.2 mm) 20 ms 81 ms
10" (254.0 mm) 47 ms 124 ms
12" (304.8 mm) 61 ms 144 ms
14" (355.6 mm) 73 ms 155 ms
  • Damping time is defined as the time required for the amplitude of the vibrations to reach 1% of the initial value after being struck.

8" (203.2 mm) Long Posts

10" (254.0 mm) Long Posts

12" (304.8 mm) Long Posts

14" (355.6 mm) Long Posts

DP14A SmartPack Packaging
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DP14A Packaging
Smart Pack

Smart Pack Goals

  • Reduce Weight of Packaging
  • Increase Usage of Recyclable Materials
  • Improve Packing Integrity
  • Decrease Shipping Costs

Thorlabs' Smart Pack Initiative is aimed at minimizing waste while providing adequate protection for our products. By eliminating any unnecessary packaging, implementing design changes, and utilizing eco-friendly materials, this initiative seeks to reduce the environmental impact of our
product packaging. 

The updated packaging for the products on this page primarily consists of recycled paper products and weighs 66% less than the original packaging. This weight change results in a 74% reduction in travel-based CO2 emissions per year, based on typical product sales. 

As we move through our product line, we will indicate re-engineered, eco-friendly packaging with our Smart Pack logo, which can be seen above

Posted Comments:
user  (posted 2023-09-12 16:12:37.04)
Can this post be fixed on a breadboard using the standard 1.5" clamping fork?
jdelia  (posted 2023-09-13 08:15:33.0)
Thank you for contacting Thorlabs. The DP- series damped posts would not be compatible with a standard 1.5" clamping fork since the base of the posts is 2.85" in diameter and the 1.5" forks are intended for pedestal bases 1.85" in diameter. We suggest mounting the damped posts on a breadboard by using cap screws with the four 1/4"-20 (M6) counterbored holes on the bottom.
Cang Zhao  (posted 2023-07-12 00:44:26.003)
What is the load capacity?
jdelia  (posted 2023-07-14 01:18:28.0)
Thank you for contacting Thorlabs. We unfortunately have not conducted load capacity tests for our damped posts. We have reached out to you directly to discuss your application further.
Michelle Wu  (posted 2022-10-17 15:23:32.787)
Hello, I'm wondering if you have vibration-damping posts that are shorter. It would be nice if you have one that is 6 or 7 inches tall. If not would you be able to quickly make one? Thanks
jdelia  (posted 2022-10-19 09:11:14.0)
Thank you for contacting Thorlabs. We unfortunately do not offer shorter versions of these posts as stock items. I have reached out to you directly regarding the possibility of providing custom-length damped posts.
user  (posted 2019-06-13 13:06:56.7)
Is it possible to add to the DP14A/M an extension post of 50mm on top (P50/M)?
YLohia  (posted 2019-06-13 04:11:22.0)
Hello, since both have M6 threads, the P50/M can be added to the DP14A/M using an M6 setscrew.
michael.rappaport  (posted 2017-11-15 22:43:21.883)
The 1.5" dia. damped posts are described as follows: --------------------------------- Ø1.5" Stainless Steel Posts Designed to Reduce Vibrations Lead-Free Damping Weight Design for Shorter Damping Times Compared to Solid Stainless Steel Posts 8", 10", 12", and 14" Long Versions Available Nickel-Plated Steel with Matte Finish for Long Life ---------------------------------- Why Ni-plate stainless steel? Are they really stainless steel and if so, what type? Thank you.
nbayconich  (posted 2017-12-14 10:27:49.0)
Thank you for contacting Thorlabs. These posts are actually made of carbon steel 1026 DOM not stainless steel. The nickel plating is meant to prevent corrosion of the steel. We will update our webpage to display the correct steel used in these parts.
jjean  (posted 2017-04-02 16:00:51.247)
Would it be possible to provide a custom version of the DP8A post with mirror finish instead of matte finish? Thanks!
tfrisch  (posted 2017-04-18 04:45:48.0)
Hello, I will reach out to you directly about your application. I would not recommend using a post as an optical mirror.
stump  (posted 2015-11-23 12:53:48.407)
I was thinking of mounting a solid aluminum breadboard on top of 4 DP8A's instead of the standard 1.5 inch posts but wondered if I would still get the desired damping? The measurements (and pictures showing various uses) all use post mounts anchored along the cylinder--not sitting on top. Thank you.
besembeson  (posted 2015-11-25 02:31:41.0)
Response from Bweh at Thorlabs USA: In the configuration you describe, the posts will be locked both at the top and the bottom which presents a more complex rigid system than the configuration we have tested for damping times we show on the website. It would seem you might gain little by using the damped posts in this manner but overall it will be a coupled system that we don't have damping time data for. The resonant frequency will also depend on the size/weight of the breadboard and setup that you have. In our tests, the top end of the posts are free standing.
urbancic  (posted 2015-09-17 12:20:56.087)
Dear Sir or Madam, I'm interested in the Ø1.5" Damped Posts but I was wondering if is possible to get them other custom lengths. Best regards, Jurij
besembeson  (posted 2015-10-05 01:18:15.0)
Response from Bweh at Thorlabs USA: Yes we can provide this. We will follow-up with you.
john.chiaverini  (posted 2014-04-24 09:26:19.37)
What are the masses (or weights on earth) of the DP8A and the DP14A? Thanks. John C.
bsanii  (posted 2013-11-22 11:17:54.79)
We bought the DP14A as a replacement for the DP14, because the base was welded on. Unfortunately we missed that you also removed the 1/4-20 thread on the top of the post, which we need. A couple questions: Can we tap the top of the DP14A, or will that release sand or the like? Alternatively, any strategies for keeping the base attached to the post on the DP14? I was about to buy some locktite. Thanks, Babak
cdaly  (posted 2013-12-04 01:54:46.0)
Response from Chris at Thorlabs: Thank you for your inquiry. There's no reason you cannot tap the bottom of the DP14A. As long as you do not go further than an inch in depth, you will not even make it through the base plate piece. We can provide a custom version of the DP14A with a tap on the top if you would like though. If you would like to epoxy the base on the DP14, I would suggest Loctite 2760.
tcohen  (posted 2012-07-03 10:10:00.0)
Response from Tim at Thorlabs: These posts are sealed with Loctite 2760 on the threads. I have contacted you to further discuss the suitability of this post.
jonathan.newport  (posted 2012-06-27 15:32:10.0)
Are these posts sealed sufficiently to operate in vacuum at ~10^-6 torr? Thanks!
tcohen  (posted 2012-05-22 10:25:00.0)
Response from Tim at Thorlabs: Thank you for your feedback! We are testing this and will provide you with an answer shortly.
user  (posted 2012-05-16 16:25:01.0)
What is the first natural frequency of vibration for the damped post DP14?
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Ø1.5" Damped Posts

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
DP8A Support Documentation
DP8AØ1.5" Dynamically Damped Post, 8" Long
DP10A Support Documentation
DP10AØ1.5" Dynamically Damped Post, 10" Long
DP12A Support Documentation
DP12AØ1.5" Dynamically Damped Post, 12" Long
DP14A Support Documentation
DP14AØ1.5" Dynamically Damped Post, 14" Long
+1 Qty Docs Part Number - Metric Price Available
DP8A/M Support Documentation
DP8A/MØ1.5" Dynamically Damped Post, 8" Long, Metric
DP10A/M Support Documentation
DP10A/MØ1.5" Dynamically Damped Post, 10" Long, Metric
DP12A/M Support Documentation
DP12A/MØ1.5" Dynamically Damped Post, 12" Long, Metric
DP14A/M Support Documentation
DP14A/MØ1.5" Dynamically Damped Post, 14" Long, Metric