1.8mm pitch is close to 14tpi, 1/2" BSP is 20.995 OD so could be that

Jason just beat me to it – BSP 1/2". common in tube or pipe work. Noel. I got the bronze medal

Edited By noel shelley on 17/09/2023 13:58:34

It looks like an American feeder that we have, so likely to be made to Imperial dimensions, rather than Metric dimension..

1/2 BSP is 0.825 (20.955 mm ) OD with a core of 0.734" (18.644 ) and is 14 tpi.

American pipe threads usually differ from BSP by 1 pitch, but in this case both are 14 tpi. but will be 60 degree rather than 55 degree Whit form.

So a wild guess suggests 1/2 NPS as close to your measurements (1/2 NPS is 0.840" (21.36 mm) OD, with a core diameter of 0.747 – 0.759" (18.97 – 19.23 mm  )

Howard

Edited By Howard Lewis on 17/09/2023 14:52:48

It might be worth measuring other dimensions if there is a concern that US threads may be used. If the rest of the product is metric, the thread is more likely to be BSP / G, the "metric" standard.

Brian G

Any manufacturing facility will try to work to standard threads, for costv reasons, unless aiming to capture a niche in the aftermarket.

So a non standard thgread will only be used for a very good reason (Exclusivity being one )

If the feeder is of American origin, *As are some sold in UK ) the thread is most likely to be 1/2 NSP.

If it is UK manfactured, might well be 1/2 BSP. Both are 14 tpi, but different thread form. So one may screw into the other.

Probably won't matter too much, since no sealing or great tensile loads involved.

If Continental might well be what they call Gas, (Or Gaz ) but actually BSP.

The main thing is to be able to secure the feeder to post withot fear of it falling off, or spinning in the wind.

Howard

Edited By Howard Lewis on 18/09/2023 13:22:40

Fully agree, on this spendid forum, with load of very techincal help, things are very often over thought sometimes?

My referance to Gripfill, have a look on Screwfix or wherever, to my my mind was a realistic solution, especially with ragging up the pole. As I said, to me there are far more important things to do than whittle about what the tread is, its a support for a bird feeder, plastic or ali, we dont know. As usual we are asked to find a solution without the full facts, its still a bird feeder support.

Pete

If someone produces a table of bird feeder threads and other useful standards like watering can rose tapers, outside tap connector threads (there are at least three) and pea netting mesh sizes, we could produce a pull out for MEW.

Neil

Clearly, Ed’s intention is to erect his bird feeder on a pole.

The need to measure and therefore determine whether thread pitch, profile, and diameters, conform with a particular (engineering) standard is understandable. It offers a simple solution to the perceived home workshop limitations and available tools. Howard’s point too is also valid as far as ‘design economy’ is concerned.

This however, is where things come unstuck and why I couldn’t resist a bit of superficial nit-picking. After all it’s ‘only’ plastic not an exotic material, so who cares?

Well, after years in TS often analysing a plethora of design-related product failures, I do for one!

Fully respecting Ed’s plastic ‘bird-feeder-on-a-pole’ issue, my comments are more a message for readers led into the impression that engineering standards are equally applicable to plastics. That is not necessarily true!

Choosing an off-the-shelf mechanical engineering standard can invite failure. Thus we see yet another product assigned into the bl***y plastic category.

While looking up suitable thread standards for plastics materials, and especially responding to Neil’s suggestion, take a squiz at this one.

DIN 6063-1 – Threads, mainly for plastic containers – Part 1: Buttress threads, dimensions.

**LINK**

At least that’ll be a start.

Good luck to all who sail in her.

Sam

I am not sure that it matters what the thead is, Ed has measured the internal size and the pitch can be carefully counted, thread form can be estimated? So there is enough information to start screwing until a nice fit is achieved to my mind?

We are not needing high precision engineering and with a bit of glue the job would be a good un….or could it be a 3D printing project?

Pete

Is pull out a suitable phrase when talking about threads?

Sam,

Looking at Ed's images, the feeder looks (to me anyway) to be die-cast rather than plastic.