Hi,

I recently found a nice little green Mickey KM in an antiques store, looks great after a clean and polish, but it needed a back. So I have sourced a back board, but now am having trouble finding a couple of the screws to secure it.

The screws that fit in to the bakelite threads at the top sides of the radio are fine (1/8" I would say), but have had no luck finding the two bottom screws that go into the chassis. (Note these are seperate to the holes that secure the chassis to the case which are also 1/8"). These are a bit smaller, and not sure what size they are either. I had no luck at Bunnings, Masters or Jaycar.

I can post a pic if needed.

Anyone thoughts or suggestions greatly appreciated.

Regards,

Damien

Most likely Whitworth. Try an industrial supplier.

Thanks Redxm,

Do you know what size they are?

Regards,

Damien

Are they metric? or maybe the non-metric used in the USA?
https://en.wikipedia.org/wiki/Unified_Thread_Standard

There would have been very few metric threads used in Australia at that time. Anything with a local or British influence before the early 1970s tended to come with a Whitworth thread and anything with a US influence used either UNC or UNF.

I am not sure of what the Astor Mickeys would have come with but I'd lean towards Whitworth as I've heard others mention it here in the past for other brands.

One way to be sure is to grab a screw off another Mickey, take it to a specialist fastener shop such as Bearfast or Mr Stainless and they will tell you what it is with a quick look and will most likely be able to give you a box of them.

Thanks All,

Yes Brad my first thought was to do that with my KL Mickey, but guess what, the KL Mickey uses standard 1/8" all around. I will have to chase up someone who has one.



Regards,

Damien

Thanks Brad,

Hmmm, my last posted before I finished typing. So to wrap up, thanks Brad too for some places to look for them. I could always take the radio in, and see what they think.

Regards,

Damien

One of the most common screws (metal threads) was actually 5/32" in Australian sets. I think I have bought 1/8" at Bunnings? Some actually used 3/16". Beware some sales drongo's cant tell one thread type from the other, yet work in bolt suppliers? We have one here.

Where a lot of problems occur is from warping, monkeys using self tappers, or screws that are too long. I normally clear the holes with a bottoming tap to ensure all is well. The set of taps is also useful for determining the thread as well.

If you are using screws that small & a fibre back, use washers.

Marc

Thanks Marc,

OK that makes sense, and sounds like good advice. Much appreciated.

Regards,

Damien

Taking a step back. I note Bunnings here has a board with various thread & screw sizes. Might go down that far? But the catch is you need an example.

A metric bolt anywhere near the size of a Whitworth will not screw into it as the thread angle is 60 degrees and WW 55.

US "Dutton" (UNF) thread is also 60 degrees, but they go in Gauge until they get to 1/4" and are not the same diameter as the Logical WW & Metric.

I note on a special bolt in the Grigsby - Grunow here there is a nut missing. I can see me making one for it.

Marc

I will have all screws to fit backboards once again very soon - I have a supplier