Correct Fastener ID
 

Can anybody please tell me the correct terminology for one of these? I need to find some as mine are rotten.

Right-hand thread machine screw with a left-hand thread wood screw. These are used to mount my speaker out of my Ekco radio.

Regards
Poppydog

Re: Correct Fastener ID
 

Not something I have come across. The closest is some types of decking screw that have a portion of left-hand thread adjacent the head, but the other end is ordinary have right hand woodscew thead.
You may find that the original screws will clean up nicely with a circular wire brush on a bench grinder or an electric drill such as a Dremel.

Re: Correct Fastener ID
 

Something like these :)

https://www.tubesandmore.com/product...unting-studnut

Cheers Mike T

Re: Correct Fastener ID
 

Wilmslow audio supplied them when I built speakers.

David

Re: Correct Fastener ID
 

I must be missing something!
Unless you intend regularly removing and replacing the speaker, what advantage do they have over straight-through machine screws?

Re: Correct Fastener ID
 

Something like this may be adaptable :

https://www.kjfaudio.com/product/hex...r-wood-type-e/

Re: Correct Fastener ID
 

If you can't find replacements, try leaving the rusty screws in phosphoric acid for an hour.

It will remove/loosen/convert the rust. You may need to use an old toothbrush or scourer to remove some deposits. The results can be impressive.

Some people use citric, oxalic and acetic acid.

Re: Correct Fastener ID
 

Citric acid is quite safe (lemon juice), as is acetic acid (vinegar).
Oxalic acid is very good at removing rust stains. But be careful with oxalic acid, it is poisonous. It is present in rhubarb leaves and, to some extent, rhubarb stems, too. It is the reason why rhubarb shouldn't be cooked in aluminium saucepans; it dissolves the aluminium, but it does leave the pan looking beautifully shiny!
Colin.

Re: Correct Fastener ID
 

Hi!

Speed and ease of insertion!

The larger shoulder with the LH screw thread enables the screws to be driven in anticlockwise with a power tool until the head is flush with, or slightly sunk into, the surface of the baffle-board, they then have the advantage of staying in place whilst the LS drive unit is secured to the rear of the baffle with nuts and washers, something a conventional countersunk machine-screw doesn't have!

Unfortunately I haven't been able to identify a name for them either - self-retaining wood bolts perhaps?

Chris Williams

Re: Correct Fastener ID
 

Thanks for all the replies and the links, unfortunately I can't seem to find the sizes I want. On mine the wood screw thread on a couple them has rotted and they have lost their "grip" so I have ended up having to carefully remove the speaker cloth to get them out. For now I have wound some very thin wire around the remaining woodscrew thread, put a small dollop of epoxy on them and wound them in as best I can, they seem to be holding. Not a class repair :-] but what else can I do? As said in a previous thread, this isn't the greatest example of an Ekco radio.

Surprised nobody on here knows the correct terminology for them though??

Regards
Poppydog

Re: Correct Fastener ID
 

They must have had a name once, but it would probably have been more cabinet maker trade oriented, so not so well known. Maybe as bland as "blind or single sided speaker mounting post" or some-such, or even just a pattern number.

Re: Correct Fastener ID
 

RS used to do them about 30 years ago (not any more though) and called them 'Speaker Screws' (including the quotes) in the catalogue. So no proper name there either.

Re: Correct Fastener ID
 

All parts still have them Amp screws - speaker mounting screw (12) with wood and machine thread (lock nuts included)
Part number 2253409
Bob

Re: Correct Fastener ID
 

I appreciate the advantages for production, but what I meant (and should have said) is why not replace them with ordinary machine screws? Authenticity, or something not quite so obvious?

Re: Correct Fastener ID
 

Hi Poppydog,
I'm sure I've got a few of those in my miscellaneous screws box. I seem to remember they came from a record player I stripped down some 35 years ago!! You are welcome to them if I still have them. Unfortunately, I won't be near said screw box for another month if you can wait that long?

Cheers
Nick

Re: Correct Fastener ID
 

Hello Nick, I ended up re-using the old ones (see post 10). Thanks for the offer though:).
regards poppydog