Products Home / Optical Systems / Objective Lenses, Scan Lenses, and Tube Lenses / Microscope Objective Accessories / Microscope Objective Threading AdaptersMicroscope Objective Threading Adapters
- Integrate Objectives with Industry-Standard Threads into Nosepieces with M32 x 0.75 or SM2 Threads
- Options Compatible with Thorlabs’ Bergamo® and Cerna® Microscope Systems
M32RMSS
External M32 x 0.75 Threads
and Internal RMS Threads
M32M34S
External M32 x 0.75 Threads
and Internal M34 x 1.0 Threads
CSN100
M32M25S
N40X-PF
M32M25S Adapter Connecting a Nikon Objective to a Cerna Nosepiece
M2M40S
External SM2 Threads and Internal M40 x 0.706 Threads
Related Items
Please Wait
| Item # | Internal Threads | External Threads |
|---|---|---|
| M32RMSS | RMS (0.800"-36) | M32 x 0.75 |
| M32M25S | M25 x 0.75a | |
| M32SM1S | SM1 (1.035"-40) | |
| M32M26S | M26 x 0.706 | |
| M32M27S | M27 x 0.75 | |
| M32M271S | M27 x 1.0 | |
| M32M32S | M32 x 0.75 | |
| M32M34S | M34 x 1.0b | |
| M32M40S | M40 x 0.706 | |
| M2M32S | M32 x 0.75 | SM2 (2.035"-40) |
| M2M34S | M34 x 1.0b | |
| M2M40S | M40 x 0.706 |
Features
- Externally M32 x 0.75-Threaded Adapters Compatible with Bergamo® and Cerna® Microscope Systems
- Externally SM2-Threaded Adapters Compatible with the CSA2100 Cerna Mounting Arm
- Internal Threading Compatible with Olympus, Nikon, Zeiss, and Leica Objectives
- Lip Prevents Over-Threading into Microscope Nosepieces
- Solid Brass Construction
These Brass Microscope Adapters can mate an externally threaded microscope objective to an internally M32 x 0.75- or SM2-threaded nosepiece. The design includes a flange to prevent over-threading the adapter or the objective into a microscope nosepiece, keeping the objective at the proper position and preventing damage to the optics inside the housing. In addition, the brass construction is harder than aluminum which reduces thread binding. The M32M32S adapter was created since many M32 x 0.75 threaded nosepieces have recessed threads. Due to the large diameter of some objectives, such as the TL10X-2P, a smaller diameter mount is needed to properly load in certain mating pieces. Each adapter has spanner wrench holes or slots for compatibility with our SPW801 Adjustable Spanner Wrench to help thread the adapters into a microscope nosepiece.
To view our entire line of thread adapters, please see our Interactive Adapters Selection Guide.
| Item # | Typical Application | External Threads | Internal Threads | |
|---|---|---|---|---|
| M32RMSS |  |
Integrate RMS Objective with M32 x 0.75 Mount | M32 x 0.75 | RMS (0.800"-36) |
| M32M25S |  |
Integrate M25 x 0.75 Objective with M32 x 0.75 Mount | M32 x 0.75 | M25 x 0.75 |
| M32SM1S |  |
Integrate SM1 Lens Tube with M32 x 0.75 Mount | M32 x 0.75 | SM1 (1.035"-40) |
| M32M26S |  |
Integrate M26 x 0.706 Objective with M32 x 0.75 Mount | M32 x 0.75 | M26 x 0.706 |
| M32M27S |  |
Integrate M27 x 0.75 Objective with M32 x 0.75 Mount | M32 x 0.75 | M27 x 0.75 |
| M32M271S |  |
Integrate M27 x 1.0 Objective with M32 x 0.75 Mount | M32 x 0.75 | M27 x 1.0 |
| M32M32S |  |
Integrate Large Diameter M32 x 0.75 Objective with Recessed M32 x 0.75 Mount | M32 x 0.75 | M32 x 0.75 |
| M32M34S |  |
Integrate M34 x 1.0 Objective with M32 x 0.75 Mount | M32 x 0.75 | M34 x 1.0 |
| M32M40S |  |
Integrate M40 x 0.706 Objective with M32 x 0.75 Mount | M32 x 0.75 | M40 x 0.706 |
| M2M32S |  |
Integrate M32 x 0.75 Objective with SM2 Mount | SM2 (2.035"-40) | M32 x 0.75 |
| M2M34S |  |
Integrate M34 x 1.0 Objective with SM2 Mount | SM2 (2.035"-40) | M34 x 1.0 |
| M2M40S |  |
Integrate M40 x 0.706 Objective with SM2 Mount | SM2 (2.035"-40) | M40 x 0.706 |
Thorlabs' Threading Specifications
Threading specifications are given below for our adapters so that you can machine mating components to suit your application. Please note that other manufacturers may have different tolerances for these threads. For other thread specifications that are not listed here, please contact Tech Support.
| RMS Threading | |||
|---|---|---|---|
| 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" |
| M25 x 0.75 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 24.977 mm | Min Major Diameter | 25.000 mm |
| Min Major Diameter | 24.837 mm | Min Pitch Diameter | 24.513 mm |
| Max Pitch Diameter | 24.49 mm | Max Pitch Diameter | 24.659 mm |
| Min Pitch Diameter | 24.379 mm | Min Minor Diameter (and 83.3% of thread) | 24.188 mm |
| Max Minor Diameter | 24.165 mm | Max Minor Diameter (and 64.9% of thread) | 24.378 mm |
| SM1 Threading | |||
|---|---|---|---|
| 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" |
| M26 x 0.706 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 25.977 mm | Min Major Diameter | 26.0 mm |
| Min Major Diameter | 25.838 mm | Min Pitch Diameter | 25.541 mm |
| Max Pitch Diameter | 25.519 mm | Max Pitch Diameter | 25.685 mm |
| Min Pitch Diameter | 25.41 mm | Min Minor Diameter (and 83.3% of thread) | 25.236 mm |
| Max Minor Diameter | 25.213 mm | Max Minor Diameter (and 64.9% of thread) | 25.417 mm |
| M27 x 0.75 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 26.977 mm | Min Major Diameter | 27.000 mm |
| Min Major Diameter | 26.837 mm | Min Pitch Diameter | 26.513 mm |
| Max Pitch Diameter | 26.49 mm | Max Pitch Diameter | 26.660 mm |
| Min Pitch Diameter | 26.378 mm | Min Minor Diameter (and 83.3% of thread) | 26.188 mm |
| Max Minor Diameter | 26.165 mm | Max Minor Diameter (and 64.9% of thread) | 26.378 mm |
| M27 x 1.0 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 26.95 mm | Min Major Diameter | 27.0 mm |
| Min Major Diameter | 26.58 mm | Min Pitch Diameter | 26.35 mm |
| Max Pitch Diameter | 25.0 mm | Max Pitch Diameter | 26.52 mm |
| Min Pitch Diameter | 24.8 mm | Min Minor Diameter (and 83.3% of thread) | 25.917 mm |
| Max Minor Diameter | 23.704 mm | Max Minor Diameter (and 64.9% of thread) | 26.153 mm |
| M32 x 0.75 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 31.977 mm | Min Major Diameter | 32.000 mm |
| Min Major Diameter | 31.837 mm | Min Pitch Diameter | 31.513 mm |
| Max Pitch Diameter | 31.49 mm | Max Pitch Diameter | 31.663 mm |
| Min Pitch Diameter | 31.376 mm | Min Minor Diameter (and 83.3% of thread) | 31.188 mm |
| Max Minor Diameter | 31.165 mm | Max Minor Diameter (and 64.9% of thread) | 31.378 mm |
| M34 x 1.0 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 33.974 mm | Min Major Diameter | 34.000 mm |
| Min Major Diameter | 33.794 mm | Min Pitch Diameter | 33.350 mm |
| Max Pitch Diameter | 33.324 mm | Max Pitch Diameter | 33.520 mm |
| Min Pitch Diameter | 33.199 mm | Min Minor Diameter (and 83.3% of thread) | 32.917 mm |
| Max Minor Diameter | 32.891 mm | Max Minor Diameter (and 64.9% of thread) | 33.153 mm |
| M40 x 0.706 Threading | |||
|---|---|---|---|
| External Thread | Internal Thread | ||
| Max Major Diameter | 39.969 mm | Min Major Diameter | 40.000 mm |
| Min Major Diameter | 39.830 mm | Min Pitch Diameter | 39.542 mm |
| Max Pitch Diameter | 39.511 mm | Max Pitch Diameter | 39.670 mm |
| Min Pitch Diameter | 39.414 mm | Min Minor Diameter (and 83.3% of thread) | 39.236 mm |
| Max Minor Diameter | 39.206 mm | Max Minor Diameter (and 64.9% of thread) | 39.405 mm |
| SM2 Threading | |||
|---|---|---|---|
| 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" |
| Posted Comments: | |
Levin Hafa
(posted 2023-02-13 11:36:14.023) Hi, Is it possible to receive a quote for an M34 external M25 internal adapter?
Best regards
Levin Hafa Devin Porter
(posted 2022-03-07 20:37:54.29) I have a nikon objective (M25 x 0.75 threading) that I am trying to use with a zeiss axiovert microscope (turret threading appears to be about 25 mm). Is there an adapter that we can use?
Thanks,
Devin cdolbashian
(posted 2022-03-15 09:43:13.0) Thank you for reaching out to us Devin. Threading in microscopy is often very specific to the model of the microscope and corresponding objective turret used. I have reached out to you to discuss the particular model of Zeiss Axiovert, and the objective threading therein. It is likely we do have a threading adapter for you although we first need to correctly identify the threading used on your microscope. SANDEEP MISHRA
(posted 2021-08-03 16:02:35.0) I want to use Olympus W20.32x0.706 (RMS) Objective to Nikon Microscope. Nikon objective have M25x0.75 thread.
Please suggest the adapter for the same.
Thanks YLohia
(posted 2021-08-05 01:22:09.0) Hello, thank you for contacting Thorlabs. Unfortunately, we currently do not offer an internal RMS to external M25 x 0.75 thread adapter. We will consider looking into offering such an item in the future. Andres Medina
(posted 2020-09-15 17:54:32.807) Hello. I'm looking for an adapter of 0.75 inch diameter to 1.0 inch diameter. The idea is to use Nikon objectives in a Zeiss microscope. Can you help me to decide which option is better?
Thanks,
Best regards,
Andres Medina YLohia
(posted 2020-09-18 02:28:21.0) Hello Andres, thank you for contacting Thorlabs. Based on our direct discussion, in order to convert the M25 x 0.75 threads of the objective to the RMS threads of the microscope, you will need the RMSA2 adapter. Tobias Noebauer
(posted 2020-08-31 21:00:44.693) We keep having issues with this adapter getting stuck in a microscope objective thread. I think this is because of the two d=0.06in holes that go through the flange ring (the face with the markings). These holes have sharp edges on the opposite side of the flange ring, which get pressed against the microscope housing when the adapter is fastened. These sharp edges create extra friction that can get the adapter stuck quite firmly. Not even the spanner wrench tool can help in these situations, we have to use WD-40 and some special pliers. I would suggest not to drill these holes all the way through the flange ring but leave them blind. Thank you! YLohia
(posted 2020-09-01 04:30:15.0) Hello Tobias, thank you for your feedback. We're always looking for ways to improve our products, so any thoughts on such matters are always appreciated. I have posted your suggestions on our internal engineering forum for further consideration. |
Additional Microscope Objective Accessories
 Microscope Thread Adapters |