FAQ: Screw Threads we use

Here are summaries and links to discussions for Frequently Asked Questions.

Moderators: ChrisR, Chris S., Pau, rjlittlefield

ChrisR
Site Admin
Posts: 8546
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

FAQ: Screw Threads we use

Post by ChrisR »

I believe this list is correct as far as it goes.
I know there are more, and will add as I hear of them.
Suggestion - advise edits needed by PM, or this forum "thread" will grow forever :)
Admin - please edit.

With thanks to many contributors =D>

Lens and Objective mounting threads:

Code: Select all

0.8" x 36tpi         RMS microscope objectives Includes many Finite objectives (except eg Nikon  BDs;, 
                     and some Nikon Infinites including CF and BE.             
25mm x 0.5mm         Schneider enlarging lenses 
25mm x 0.75mm        Nikon CFI60 Infinite microscope objectives, 
1" x 32tpi           C mount (32 tpi = 0.794mm) 
1.035" x 40tpi       (40 tpi = 0.635 mm) ThorLabs SM1 lens tube system for 1" diameter optics. Many adapters available, to objective etc, threads.   
26mm x 36tpi         Mitutoyo infinity microscope objectives (36 tpi = 0.706mm) 
26mm x 36tpi         Olympus neo splan/dplan infinity metallurgical objectives
26mm x 0.75mm        Nikon BD 210mm finite objectives,  Nikon LU Infinites, and others 
26mm x 0.75mm        Nikon Measurement Microscopes (MM40 and others)
27mm x 0.75mm        Nikon BD infinity objectives 
27mm x 0.75mm        Zeiss Infinity Microscope Objectives
28mm x 0.5mm         Schneider enlarging lenses 
28mm x 0.75mm        Some Reichert Microscope Objectives
29.5mm x 0.5mm       Schneider M-Componon 28mm f/4, M-Componon 50mm f/4, M-Componon 80mm f/4                  (?)
30mm x 0.5mm         Schneider enlarging lenses 
30.5mm x 0.5mm       Schneider enlarging lenses 
32mm x 0.75mm        Nikon LU BD Plan series of large industrial objectives 
32.5mm x 0.5mm       Some Enlarger lenses eg Schneider (eg135mm f/5.6) Rodenstock, early Nikon EL (eg 80, 105). 
                     Some Nikon EL came with adapter to 39mm 
35mm x 0.5mm         Schneider enlarging lenses 
39.0mm x 0.75mm      Schneider MAKRO-SYMMAR HM 180mm f/5.6 
39mm x 26tpi         Leica lens mount. The Enlarger lens standard. Often quoted as 1mm (26 tpi = 0.977mm) 
40mm x 36TPI         Mitutoyo BD Plan APO Microscope Objectives (36 tpi = 0.706mm)
40mm x 0.75mm        Leitz eg Photar Symmar eg 50mm f/2.8 
42mm x 0.75mm        T2 standard mount 
42mm x 1mm           "M42" Pentax/Praktika lens mount, a common standard 
43mm x 0.75mm        Schneider enlarging lenses 
45mm x 0.75mm        mount for 75mm, 95mm, and 105mm Printing-Nikkors, 
                     also used on the adapters and extensions for the Rodenstock Modular Focus Unit.
50mm x 0.75mm        Schneider enlarging lenses 
50mm x 1.0mm           Leica / Wild Heerbrugg M3B, M3C, M3Z, MS5, MZ6, MZ7.5, MZ9.5
52mm x 1.0mm            Leica Stereo Zoom S4E, S6, S6D, S6E, S6T, S8APO
55mm x 0.75mm        Schneider enlarging lenses 
66mm x 0.75mm        Schneider enlarging lenses 
77mm x 0.75mm        Schneider enlarging lenses 
90mm x 1mm           Schneider enlarging lenses

Note "Mxx" is considered equivalent here to "xxmm"
eg M42 == 42mm
Filter threads: generally 0.75mm pitch at 43mm diameter and larger, 0.5mm pitch at 40.5mm diameter and smaller. Exceptions occur in the smaller diameters and some diameters are available in both.
See eg Hoya Catalogue P17

Enlarging lens filter threads, used eg for reversing: Pitch 0.5mm or 0.75mm, shown where known.

Code: Select all


30.5mm
   Rodenstock
      Rodagon  28mm, 35mm, 
      Rogonar-S  28mm, 35mm
   Schneider  
      Old Style Componon *, 28mm, 35mm, 50mm, 60mm, 80mm, 105mm
      Xenon 40mm f/2.8 

34.5mm
   Nikon - check, there are two styles of El Nikkors
      El-Nikkor 50mm F/4
      EL-Nikkor 75mm f/4
      EL-Nikkor 80mm f/5.6
      EL-Nikkor 105mm f/5.6 

35.5mm 
   Schneider 
      Comparon 105mm
      Componar C105mm
      Componon WA60mm

40.5mm x 0.5mm
   Nikon
      El-Nikkor 50mm f2.8 & N, 
      El-Nikkor 63mm f2.8 & N, 
      El-Nikkor 75mm f5.6 & N,  ??
      El-Nikkor 105mm f5.6 & N 
   Rodenstock, 
      Rodagon 35mm, 50mm, 75mm, 80mm, 105mm, 
   Schneider 
      Comparon 135mm f/5.6 
   Yashica 40mm f3.5

43mm  x 0.75mm    
   Nikon
      El-Nikkor 135mm f/5.6 and others
   Rodenstock, 
      Rogonar-S, 50mm, 60mm, 75mm, 90mm, 105mm, 
      Rodagon 50mm, 60mm, 80mm, 105mm, 135mm
      Rodagon-WA, 40mm, 60mm, 80mm, 
      Rodagon-G, 50mm, 105mm, 
      Apo Rodagon-N, 50mm, 80mm, 90mm, 105mm, 
      Apo Rodagon-D, 1:1 75mm f/4, 2:1 75mm f/4.5
   Schneider
      Comparon 50mm, 75mm
      Componon New Style 50mm, 60mm, 75mm, 105mm
      Componon-S 50mm, 80mm, 100mm*
      Componon WA 40mm
      HM Apo Componon 40mm f/2.8, 45mm f/4, 50mm f/2.8 
   Computar/Kowa
      DL 50mm f/2.8 
      DL 50mm f/2.8 
      DL 55mm f/1.9 
      Varifocal 50-90 
      DL 135mm f/5.6 
      DL 65mm f/3.5 
      DL 80mm f/4.5 
      DL 90mm f/4.5 
      DL 105mm f/4.5

49mm
   Rodenstock 
      Rodagon-G 150mm
   Schneider
      Componon-S 135mm, 150mm

52mm x 0.75mm     135mm Schneider Componon-S
                  Computar DL 30mm f/2.8 
62mm x 0.75mm     150mm Schneider Componon-S
67mm x 0.75mm     Computar Varifocal 105-150
72mm x 0.75mm     180mm Schneider Componon-S
82mm x 0.75mm     210mm Schneider Componon-S
100mm x 1mm       240mm Schneider Componon-S
110mm x 1mm       300mm Schneider Componon-S

Notes:
"Old" and "New" style Schneider lenes are known to occur with different filter threads
Rodenstock Rodagon 28mm and 35mm, and Omegaron 25mm f/4 lenses have no filter threads on some (later?) versions

---


Minolta
Rokkor
25mm f/3.5 tba
30mm MC f/2.8 No filter thread
50mm MC f/2.8 ?
50mm f/4 ?
75mm f/4.5 ?

Copal Shutter mounts:

Code: Select all

COPAL spec.         #0	         #1	         #3	         #3s
front thread        M29.5-0.5    M40-0.75    M58-0.75    M56-0.75
back thread	    M29.5-0.5    M36-0.75    M58-0.75    M56-0.75
overall thickness   20 mm        20 mm       32 mm       28.6 mm
front to iris       10.2 mm      10.75 mm    17.7 mm     16.25 mm
mount thread        M32.5-0.5    M39-0.75    M62-0.75    M61-0.75
lensboard hole      34.6 mm      41.6 mm     65 mm       64.1 mm
iris dia            24 mm        30 mm       45 mm       45 mm


Lens register distances, and some thread sizes:
http://www.graphics.cornell.edu/~westin ... ister.html

An important macro lens listing:
http://www.macrolenses.de/objektive.php

A forum discussion of Nikon and Mitutoyo M26 objective mounting threads:
http://photomacrography.net/forum/viewtopic.php?t=12404

A "Big list of Enlarger Lenses" - many of the above are on this list but some aren't.
http://photocornucopia.com/1061.html

Note:
1" means one inch, tpi means Threads Per Inch (pitch)
One inch = 25.4mm
Last edited by ChrisR on Sat Mar 04, 2017 5:53 am, edited 59 times in total.

ChrisLilley
Posts: 674
Joined: Sat May 01, 2010 6:12 am
Location: Nice, France (I'm British)

Post by ChrisLilley »

True Leica thread-mount (LTM) is 39 mm in width and has a thread of 26 turns-per-inch Whitworth, approximately 0.977 mm.
http://en.wikipedia.org/wiki/M39_lens_mount

RogelioMoreno
Posts: 2962
Joined: Fri Nov 20, 2009 11:24 am
Location: Panama

Post by RogelioMoreno »

25mm x 0.75mm - Nikon CFI60 LU EPI series
32mm x 0.75mm - Nikon CFI60 LU BD series

Rogelio

ChrisR
Site Admin
Posts: 8546
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

I have a Nikon infinity rms objective or two. Not sure when they changed. Anyone?

RogelioMoreno
Posts: 2962
Joined: Fri Nov 20, 2009 11:24 am
Location: Panama

Post by RogelioMoreno »

ChrisR wrote:I have a Nikon infinity rms objective or two. Not sure when they changed. Anyone?
The old 45mm parfocal infinity EPI series are rms and the infinity BD series are 27mm.
The new 60mm parfocal (CFI60) are 25mm; but the BD series are 32mm.

Rogelio

pgk
Posts: 46
Joined: Sat May 15, 2010 11:37 am

Post by pgk »

FWIW - Leitz produced some Photars (such as the 50mm f/2.8 ) with an M40 x 0.75 thread mount.
Paul

Blame
Posts: 342
Joined: Fri May 14, 2010 11:56 am

Post by Blame »

Don't filter threads generally have 0.75mm pitch?

SONYNUT
Posts: 635
Joined: Sat Jan 22, 2011 2:27 pm
Location: Minnesota USA

Post by SONYNUT »

..............................................................................
Just shoot it......

rjlittlefield
Site Admin
Posts: 20853
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Re: Threads we use

Post by rjlittlefield »

ChrisR wrote:26mm x 0.75mm Nikon BD 210mm finite objectives, Mitutoyo and others (Have seen 36tpi quoted, which would be 0.70mm)
In every reference I can find, Mitutoyo threads are consistently listed as M26 x 36TPI or M26 x 0.706. Those are different ways of specifying the same thread.

In contrast, my Nikon objectives measure M25, M26, and M27 x 0.75 mm (except for the old RMS threads which are 0.8 in x 36 TPI).

It looks to me that the Nikon M26 and Mitutoyo M26 threads are fundamentally incompatible, although in some adapters the threads may fit loose enough to work either way.

Can somebody who has both types of objectives run a direct comparison to confirm this?

--Rik

ChrisR
Site Admin
Posts: 8546
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

I have both.
You're probably right. All lenses fit all adapters without apparent issues so far. Perhaps there are so few turns it doesn't give a problem. I'll see if I can measure them - not sure how!

rjlittlefield
Site Admin
Posts: 20853
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Post by rjlittlefield »

ChrisR wrote:I'll see if I can measure them - not sure how!
Direct comparison should be good enough. Just use the threads on a known objective as if they were a thread gauge. My guess that an RMS objective will mate tightly with the Mitutoyo, but the Nikon M25, M26, M27 won't quite match up.

--Rik

ChrisLilley
Posts: 674
Joined: Sat May 01, 2010 6:12 am
Location: Nice, France (I'm British)

Re: Threads we use

Post by ChrisLilley »

rjlittlefield wrote: In every reference I can find, Mitutoyo threads are consistently listed as M26 x 36TPI or M26 x 0.706. Those are different ways of specifying the same thread.

In contrast, my Nikon objectives measure M25, M26, and M27 x 0.75 mm (except for the old RMS threads which are 0.8 in x 36 TPI).

It looks to me that the Nikon M26 and Mitutoyo M26 threads are fundamentally incompatible, although in some adapters the threads may fit loose enough to work either way.

And thus I would much rather the table give the actual measurements in the units as specified, even if these mix imperial and metric units. Approximations can always be listed in the notes.

So Leica LTM is 39mm x 26tpi, not 39mm x 1mm although as Rik notes some imprecision may still allow a fit if nly a couple of threads are engaged. Similarly, I would prefer to see Mitutoyo listed as 26mm x 36tpi, as specified.

ChrisR
Site Admin
Posts: 8546
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

My guess that an RMS objective will mate tightly with the Mitutoyo, but the Nikon M25, M26, M27 won't quite match up.

Hard to tell just eyeballing the couple of threads which can be brought together, but I think you're right, so I've amended the table.

Adaptors don't always(!) seem too critical, for example a Mitutoyo screws into a C mount quite happily

Thats 26 x 0.706 into 25.4 x 0.794


Chris L - noted, thanks.
Last edited by ChrisR on Sun Feb 10, 2013 12:44 pm, edited 2 times in total.

ChrisLilley
Posts: 674
Joined: Sat May 01, 2010 6:12 am
Location: Nice, France (I'm British)

Post by ChrisLilley »

ChrisR wrote: Chris L - noted, thanks.
Thanks for the update, Chris.

rjlittlefield
Site Admin
Posts: 20853
Joined: Tue Aug 01, 2006 8:34 am
Location: Richland, Washington State, USA
Contact:

Re: Threads we use

Post by rjlittlefield »

ChrisLilley wrote:
rjlittlefield wrote: In every reference I can find, Mitutoyo threads are consistently listed as M26 x 36TPI or M26 x 0.706. Those are different ways of specifying the same thread.

In contrast, my Nikon objectives measure M25, M26, and M27 x 0.75 mm (except for the old RMS threads which are 0.8 in x 36 TPI).

It looks to me that the Nikon M26 and Mitutoyo M26 threads are fundamentally incompatible, although in some adapters the threads may fit loose enough to work either way.
And thus I would much rather the table give the actual measurements in the units as specified, even if these mix imperial and metric units. Approximations can always be listed in the notes.
My concern is for accuracy. I only care a little if the Mitutoyo thread is listed as M26 x 36TPI or M26 x 0.706. (Edmund Optics lists it both ways, on different pages.) But when somebody asks me offline or comes to our site wanting to figure out what adapter to buy, or even more, what adapter to manufacture, I think it's kind of important that they get the right numbers and know where confusion and incompatibility might arise.

There have already been two instances I know about where somebody tried screwing a Mitutoyo objective into a Nikon M26 adapter and was surprised to find that it didn't fit. I think now we understand how that might happen, even if (especially if) the adapter is accurately manufactured to spec. I've measured the Nikon's myself and I'm pretty confident they really are pitch 0.75 mm. I'm still hoping that somebody can make an independent physical measurement on a Mitutoyo, just because I'm such a skeptical guy.

--Rik

Post Reply Previous topicNext topic