outer thread AGF Technic-15 sight tunnel

Hi folks,

bit of an obscure one.....

Does anyone know the outer thread spec for the 'sight tunnel' on an AGF Technic-15 sight please?

the part is actually called an 'aperture part number 712' in the component diagram.........

http://www.agf-archery.ch/download/agf-technic-15_english.pdf

I don't mean the inner thread that accepts the sight pin - its the outer one used to move the sight tunnel in and out

thanks in advance
 

geoffretired

Supporter
Supporter
I am guessing that it is M4 but could be 8-32. Normal threads for sight threaded rods.
Is it possible to use one of the M4 screws ( 722) from the distance tube( 721) to check.
M4 and 8-32 are close to each other and can be used in some circumstances.
M4 is easy to source from engineering places, 8-32 is easily sourced from archery shops.
Are you trying to replace the threaded rod 712?
 
thanks Geoff - no not replace i just want to source a locking nut - the sight tunnel moves around a little that's all

tried sorting internal tolerances - no difference

M4 would match the inner thread not the outer - thanks

I know its not standard metric like M6 - an M6 nut is right Dia(ish), but wrong thread - its much finer than that - more like American fine or maybe UNF or sommat

cheers
 

geoffretired

Supporter
Supporter
I didn't notice that the threaded rod has a thread at one end and then a fatter rod carrying through to the adjusting end.
If your part was standard M6 it would have ten teeth per cm. If you count ten teeth and measure; you will know if its thread is finer than that.
There is a fine series in M sizes. M6 fine. Ten teeth on that series will measure 7.5 mm. Perhaps that is what you have.
If you count how many teeth there are on a 1 inch length of that part, there is an M6 equivalent in UNF it is 1/4 - 28 UNF and it has 28 teeth per inch.
There is a UNEF thread that has 32 teeth per inch so a little finer still.
 

geoffretired

Supporter
Supporter
Looking at the part 711 the slide block, that has what looks like a knurled nut on to adjust the windage; is that correct? When the threaded rod goes through that, what prevents the rod from turning while you are adjusting it with the knurled nut?
 
yes Geoff - i just need a locking nut to lock that which will tension the sight tunnel and stop it from wobbling

so I need to know the outer thread - I have asked AGF - they are usually pretty good at responding
 

norfolkngood

New member
It’s an M8x1mm pitch thread, commonly known as M8 fine. You will have great difficulty finding a nut to fit. A 5/16” UNF thread is roughly the same outside diameter but is 24 TPI and your thread is 25.4 TPI ( if converted from metric to imperial). If you can find a 5//16” UNF nut and saw/ file it down to 2mm thick it will probably be close enough.
 

norfolkngood

New member
If you can find an old Yamaha EX plunger button that will be the same thread, somebody must have one and you can use the locknut off that.
I just looked on the bay and you can buy two stainless half nuts for ?1.45 posted, item 221322418610.
 

jonUK76

Member
It?s an M8x1mm pitch thread, commonly known as M8 fine. You will have great difficulty finding a nut to fit. A 5/16? UNF thread is roughly the same outside diameter but is 24 TPI and your thread is 25.4 TPI ( if converted from metric to imperial). If you can find a 5//16? UNF nut and saw/ file it down to 2mm thick it will probably be close enough.
If it's just an M8 x 1mm nut required, then there's a few fastener suppliers on eBay that do them, for example - here

EDIT - Ah I see from subsequent post you found one of them :)
 

Chil

New member
I have the same problem with an AGF sight and knew that if I waited long enough someone would come up with the answer.
 
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