Tweet
I got these hiFi speakers which means they had Biwiring so it involves two pairs of binding post contacts for each speaker.
They were from my moms which I set up in 2002 new and a few years ago she had a small problem in her retirement apartment where some contractors came in and moved and cleaned everything and put it back.
Well I got these speakers back and one of them was missing two of the gold plated knurled nuts on the binding posts.
So the normal jumper between the pairs is not making good electrical contact - I don't know how they were playing but it must have happened with the contractors because I surely did not leave it like that.
So I figured the missing knurled nuts could be replaced with regular threaded nuts.
So I looked at it and thought 3/8" so I tried some 3/8" standard 16 tpi nuts and they were about the right size but thre threads locked in about a turn. So a close look, the threads are finer so probably 3/8-24tpi standard fine threads. Metric passed my mind at this point and I thought, 2002, and these Infinity speakers are labeled Made in USA so I figured SAE/ANSI standards.
A while later I have a pair of 3/8-24 nuts from one the blue box store but when I try them on the posts they only go on about 4 turns and lock up.
So I try to get some more nuts from the Orange box store with no luck. I find the drawer and bin where they should be as labeled but the bin is full of everything but nuts. The guy with the apron comes by and says did you find what you need and I explain I need the nuts that should be in this bin and he says, yeah, they are a mess and walks off. Sh*t.
So i order a thread checker from Amazon it comes next day and I check the nuts they are very rough and tight so I use my electric drill driver and run the 3/8"-24 tap I have in my HF set back and forth a couple dozen times with cutting oil and they now spin nice and freely on the 3/8-24 nut checker thread.
So the nuts still lock up after about four turns on the posts. I check the knurled nut from another post on the 3/8-24 nut checker and it threads on almost all the way, maybe 6-7 threads because its not all that long.
So I'm very puzzled.
After another day it dawns on me that maybe its metric after all. I check the knurled nut from the other post and it spins all the way down the M10 x 1 mm thread on my nut/bolt checker.
Yesirree. 24 TPI and 1 mm (which is 25.4 TPI) are so close that quite a few threads go on OK before it jams.
And 10 mm is just .015" more than 3/8" So it almost fits to the point you think something is wrong, not that hey this doesn't fit. I guess in all past metric vs inch fasteners they were never quite so close as to be nonobvious that they were off.
So I got a couple of hex coupling nuts in M10x1 coming that are long enough to actually match the knurled nut length.
I don't usually mix up metric and SAE. So overall I feel pretty stupid.
Fortunately I had the bug midway through this to order this with both metric and SAE:
They were from my moms which I set up in 2002 new and a few years ago she had a small problem in her retirement apartment where some contractors came in and moved and cleaned everything and put it back.
Well I got these speakers back and one of them was missing two of the gold plated knurled nuts on the binding posts.
So the normal jumper between the pairs is not making good electrical contact - I don't know how they were playing but it must have happened with the contractors because I surely did not leave it like that.
So I figured the missing knurled nuts could be replaced with regular threaded nuts.
So I looked at it and thought 3/8" so I tried some 3/8" standard 16 tpi nuts and they were about the right size but thre threads locked in about a turn. So a close look, the threads are finer so probably 3/8-24tpi standard fine threads. Metric passed my mind at this point and I thought, 2002, and these Infinity speakers are labeled Made in USA so I figured SAE/ANSI standards.
A while later I have a pair of 3/8-24 nuts from one the blue box store but when I try them on the posts they only go on about 4 turns and lock up.
So I try to get some more nuts from the Orange box store with no luck. I find the drawer and bin where they should be as labeled but the bin is full of everything but nuts. The guy with the apron comes by and says did you find what you need and I explain I need the nuts that should be in this bin and he says, yeah, they are a mess and walks off. Sh*t.
So i order a thread checker from Amazon it comes next day and I check the nuts they are very rough and tight so I use my electric drill driver and run the 3/8"-24 tap I have in my HF set back and forth a couple dozen times with cutting oil and they now spin nice and freely on the 3/8-24 nut checker thread.
So the nuts still lock up after about four turns on the posts. I check the knurled nut from another post on the 3/8-24 nut checker and it threads on almost all the way, maybe 6-7 threads because its not all that long.
So I'm very puzzled.
After another day it dawns on me that maybe its metric after all. I check the knurled nut from the other post and it spins all the way down the M10 x 1 mm thread on my nut/bolt checker.
Yesirree. 24 TPI and 1 mm (which is 25.4 TPI) are so close that quite a few threads go on OK before it jams.
And 10 mm is just .015" more than 3/8" So it almost fits to the point you think something is wrong, not that hey this doesn't fit. I guess in all past metric vs inch fasteners they were never quite so close as to be nonobvious that they were off.
So I got a couple of hex coupling nuts in M10x1 coming that are long enough to actually match the knurled nut length.
I don't usually mix up metric and SAE. So overall I feel pretty stupid.
Fortunately I had the bug midway through this to order this with both metric and SAE:
Attached Files
Loring in Katy, TX USA