Centrepin end-float grubscrew and centre-boss screw sizes

[Nobby]

Rapidex, Trudex and the post-War variants, such as Float Queen, Floatcraft and Perfection Flick Em.

Centreboss mounting screws: 7BA x 5/16" ( 7mm)

End-float grub screw: 4BA x 7/32" ( 4.7mm)


Pre-War Perfection Flick Em

End-float grub screw 6BA x 5/32" ( 3.97mm)

My thanks to Watermole+ and Shed Monkey for the sizes. Please reply with your own findings

[LuckyLuca]

Cheers Nobby, good info to have

[Chavender]

later improved model speedia's are also 6ba (steel) ,the earlier ones are bigger but still probably ba threaded (brass) .I would measure the early ones but don't have a thread checker comb tool .keep meaning too get one .i'll see what I can do.

[Nobby]

Yes, I must buy one too, Steve!

[Keston]

I Have a nice old screw pitch gauge and I take it this is the tool you are talking about ?
I measured the grub screw of an Allcocks C815 at 48 threads per inch so 6 BA ? Quite short at .125 (1/8) or 3.2 mm
To check I was doing it properly I also measured post war and pre war flick em reels and got the same BA as the first post with just minor variations in grub screw length.

[Nobby]

Thanks Keston.


I think we may have a problem Steve. I took my Pefection Flick Em grub screws to see if they fitted the Speedias. They didn't.

With Shed Monkey saying the PFE grub screw is 6BA and it not fitting the Speedia I'm drawn to concluding the Speedia possibly isn't 6BA after all. Incidentally, it is the early Speedia that has this small thread...in its 'pill-like' centreboss, not the later one which is a larger size.

I tried the boss mounting screw of a Trudex, 7BA apparently, and that didn't fit either. I'm wondering if Speedias were Whitworth??


So PFE and Aerial C815 should have the same thread...6BA .... can anyone check if they have both reels, please?

[Keston]

I just checked an improved Speedia and it has a 6BA thread the same as the ore war PFE and C815 . It is steel though as Steve said and has a shoulder in it so not sure if that's why you couldn't interchange them .

[Keston]

Grice & Young Avon Royal supreme is 4BA
I tried interchange with the post war Flick em and the grub screw worked fine although the Grice and young grub is much longer so protrudes well above the boss on the Flick em. Oddly though I couldn't get the shorter flick em grub to sit happily and screw into the grice &young .

[Nobby]

I just checked an improved Speedia and it has a 6BA thread the same as the ore war PFE and C815 . It is steel though as Steve said and has a shoulder in it so not sure if that's why you couldn't interchange them .

No it wasn't that...the thread wouldn't even get started...they must have changed the specification.

[Nobby]

Grice & Young Avon Royal supreme is 4BA
I tried interchange with the post war Flick em and the grub screw worked fine although the Grice and young grub is much longer so protrudes well above the boss on the Flick em. Oddly though I couldn't get the shorter flick em grub to sit happily and screw into the grice &young .

I have found that some screws have been expanded by placing a tool in the screw slot and bending the two 'halves' apart. I don't know if this was factory done or by an owner who wanted the screw to grip in the reel more...OK, I suppose, .... it's not an unheard of idea, .... but only if you get that expansion in exactly the right place.

It can be a problem playing about with 60 year old threads.....if they have been damaged, like half the nuts and bolts on the average vintage British motorcycle, you can go mad trying to work out what is going on.......