Okay, I give up. What size is it.

slushee

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I have a full set of Imperial allen keys and 2 full sets of metric ones .. but i cannot find an allen key that will fit the castle nut set screw!!!!!

What size is this little guy?
 
GAH! I just took a tonne of tools home tonight to get this all taken care of, only to be derailed by an odd-balled set screw :rolleyes:

Makes me wish I could walk into Canadian Tire and just keep trying allen keys till I find the one that will work ... prolly not a good idea though ya think?

Hopefully someone can give me the size soon .. until then, I guess I have a few beers in the fridge :dancingbanana:
 
welp, i'm pretty drunk now so I think its best if I wait till tommorrow to run to Canadian Tire :)

Thanks for the response .. I guess i'll have to re-smuggle the tools out of work again tommorrow to get this little project complete heh
 
all the ones i've done have been a 1/16 BUT once your 1/16 allen key gets worn just a bit on it's corners.... it's tit useless. use a dremel cut off wheel and shorten it 1/4 inch and try again.... or get a new allen key.
if all else fails..... a 1/16 allen key with a very tiny dab of epoxy on the end or jb quik weld. once it's set.... wait an hour anyways..... turn the key out.
 
You can be geeky about it....

.....an use allen keys as above and get hot and bothered about it fitting properly......

Or you can just put a flat head screw driver in and call it a day. It's just the castle nut set screw.
 
Yes, you can do that and it will work out very well. The actual allen wrench to use for the Norinco metric castle nut set screw is 1.5mm.

Man, a 1.5 is so sloppy in there if that's what they meant to make it, I am really disappointed in those slave labourers!

I found 1/16 to be a better fit but a torx driver and a hammer best of all.
 
I've just gone back and tried the allen wrench on several norinco flash hiders and the 1.5mm fits very well. It is all I have ever used on these castle nut set screws. I wonder if someone over in Norincoland has switched over to something else? I haven't bought an M305/M15s from the latest shipment.

Just to be sure of the size, I mic'ed my allen wrench at 1.505mm and at .0585".

As a side note, most of the chinese fasteners are of such poor quality that you are always better off to replace them. The metal that they use for these leave alot to be desired.
 
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A file and a small-but-just-a-bit-too-large Allen wrench worked for me. A few strokes on the file, test fit, turn 1/6th and relieve the next side. Eventually you will get the end small enough to get a good grip, and you will have a custom wrench for the next time you need to work on the Norinco castle nut screw.
 
So the allen key spot was stripped after all, but nothing a set of screw extractors couldn't fix!

Now on to the next problem ;)

I walked into Fastenal and plopped this little beauty of a set screw on the counter .. the dude picks it up, takes a few measurments and states "If you hadn't brought this little guy in, I would have laughed and said this thing doesn't exist" ...

So who's got replacement setscrews? :) I'm ultimatly thinking about just re-tapping it to 6-32 and grinding a little dog nose tip on a regular 6-32 set screw....
 
Okay, I give up. a M3.5x0.6 Dog Nose set screw does not exist in North America.

What would you all suggest I retap it to? 6-32? 8-32?
 
find a screw with that pitch and modify it to suit
you may have to anneal the flash hider to be able to re tap it without compounding the problem with a broken tap in tha hole. ;) trust me..... i speak from experience

i ended up sourcing a USGI / M1a castlenut set screw from brownells...... it fit just fine ;) check with them .... they may still have some.

try this ;)
h ttp://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=21408&title=CASTLE%20NUT%20SET%20SCREW
 
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