Standard Surveying Thread?

[SpurryParticipant @spurry]

[SpurryParticipant @spurry]

Having read through the interesting thread on the Leica specifications, would anyone have a definitive answer to what exactly is a Standard Surveying Thread.

It is used to attach a laser level to a tripod. The most info I can find is that it is 5/8" and 11TPI. The company I purchased the laser from are of the opinion that it is BSW, but cannot say for sure.

As a coincidence 5/8" x 11 TPI is also a standard UNC thread, but obviously a 60 deg compared to the BSW 55 deg.

In the general run of things, it probably does not not make a great deal of difference, and either would probably be suitable, but only one is correct. I am somewhat perplexed with the difficulty in finding the correct spec.

Pete

[John HaineParticipant @johnhaine32865]

I'm not sure this is definitive but it looks like the threads originated in the USA so perhaps more likely to be UNC? If you have an example male thread then a quick test with a thread gauge should tell you.

[DC31kParticipant @dc31k]

Surveying: ISO 12658-2 or DIN 18720.

Photography ISO1222 or DIN 4503-1.

[ShadowParticipant @shadow]

There are about three different normally used tripod thread sizes. 5/8"x11male, a 3 1/2" male thread and a smaller somewhat proprietary about 5/8" fine female thread. For your laser level of fairly recent manufacture I believe is 5/8"x11.

Just for info, older instrument manufacturers used their own thread size so you bought their tripods.if curious a browse at a U.S. manufacturer Chicago Steel Tape should show some current sizes.

[DC31kParticipant @dc31k]

https://www.iso.org/obp/ui/#iso:std:iso:12858:-2:ed-1:v1:en

55 degrees, so old Uncle Joe is bang up to date with GPS on his head.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Shadow on 15/09/2021 14:43:14:

There are about three different normally used tripod thread sizes. 5/8"x11male, a 3 1/2" male thread and a smaller somewhat proprietary about 5/8" fine female thread.

…

I expensively found by importing an adaptor that the USA 3½" thread isn't the same as the UK 3½" tripod thread…

I'm sure part of the problem is that standard threads are intended for fasteners rather than the screw on fittings found on lens, bottle tops, and proprietary attachments. Reasonable to expect nuts and bolts to match a standard, less likely a camera lens or beer bottle will be metric, Whitworth, or anything else quite 'normal'.

Bet I'm not the only one on the forum who occasionally makes non-standard threads to suit the job in hand. Mine are mostly metric 1.0 pitch on non-standard diameters.

Dave

[JasonBModerator @jasonb]

5/8" Whit from when I did surveying at college but expect now it's UNC just a s1/4 & 3/8 Whit camera tripod mounts are now also UNC. With both being quite slack you can use either.

[SpurryParticipant @spurry]

Thanks everyone for all the info. Most useful. So the definitive answer is a 55 degree thread or BSW.

I had bought some 5/8" UNC studding, and corresponding tap, on the gamble it was a UNC thread, as BSW is a bit thin on the ground in modern stuff.

The studding does fit the laser base without a problem, so as Jason commented, either will do.

(I have a couple of tripods, lasers, and adapters but all my measurements were so different, so as not to be much use, hence the search to find out 'exactly' what they should be)

Pete

[John ReeseParticipant @johnreese12848]

I have owned several European surveying instruments. All but one had a 5/8-11 female thread in the base. The other was a proprietary bayonet connection.

[Clive HartlandParticipant @clivehartland94829]

After 60 plus years in the Instrument trade the standard tripod screw was 5/8 x 11 bsw. On some high tech instruments like gyros it was 11/16 UNC which is 11tpi. They are nominly interchangeable as the threads are quite loose. The aviation system is 11/16 x 11 UNC, where gyros are used to align weapon systems, But, Submarine systems use 5/8 x 11 for mounting the alignment systems. As the Theodolites were used in non vertical positions they had tighter/stiffer vertical axis.

Kern us their own mounting system as some of the British older type Theodolites. Using a large diameter thread and a screw plate on the tripod.

[CirclipParticipant @circlip]

Another forum (MM) has it standardised on 5/8 x 11 BSW or UNC

Regards Ian.

[Oily RagParticipant @oilyrag]

Posted by SOD:-

I'm sure part of the problem is that standard threads are intended for fasteners rather than the screw on fittings found on lens, bottle tops, and proprietary attachments.

According to my thread 'bible' (P.A.Sidders – Guide to World Screw Threads – ISBN 0-89381-1092-9) there is a welter of standards for threads covering 'fittings' other than straight forward fasteners. For example, the 'German Bottle Closure Thread series', the 'British Bottle Closure Thread – Glass and Plastic containers', the Cordeaux thread for telegraph insulators, Water Well casing threads, Fire Hose Coupling threads, Edison Screw thread for Lamps, and a real odd one the 'British Water Tap shank rope thread'. These all being of non Whitworth form. Miscellaneous Whit forms are listed as – Condenser tube glands, Oil Drum plugs, Endoscope Lamp housings, Microscope Objectives and nose pieces, Oil Switchgear (?), Optical Instruments (Fine motion and Adjustment), Optical Instruments (metal tubes, cells and fittings), Camera Lens fitting flanges (R.P.S Standards) and finally Electrical Conduit Thread!

I remember that many moons ago when working at Alfred Herberts there was a tooling job for either India or Malaysia (but could have been China) where they wanted to manufacture water taps, the shank of the tap was the aforementioned 'British Water Tap shank rope thread' – we found the standard to this was a very early BS number (something like BS14 or so) dating from the earliest days of the BSI.

Martin

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