10mm Wide Nut with 1/4-20 Thread

[sbosecker]

I think the thread title says it all...






I have at least a dozen 1/4"-20 nuts in my fastener collection that need a 10 mm wrench to tighten them. The second picture is a brand new 1/2" long 1/4-20 bolt (7/16" head) with the said nut screwed onto it.

What's up with that?

Has anyone seen this sort of FrankenNut before?

I discovered these oddities today when I raided my fastener cabinet to put together a project. (Post 2703 on this PAGE.)


Scott

 

[LXCam]

Are you positive it's not 3/8"?

I've seen SAE one size reduced heads many times which is why I suspect...

 

[bdbecker]

Some 1/4" fasteners use 3/8" wrenches. 3/8" = 9.53mm.

https://www.engineeringtoolbox.com/us-bolt-head-wrench-size-d_1457.html

 

[GRB]

I keep 1/4-20 nuts on hand with 3/8" and 1/2" as well as the USS standard 7/16" across the flats.

10mm is less than 0.020" larger than 3/8".

 

[sbosecker]

Are you positive it's not 3/8"?

Quite positive.


Best regards,

Scott

 

[Show7d3]

Years ago I bought a cheap bolt assortment and the 1/4-20 x 1" bolts have a 10mm head on them . Do you want some oddball bolts to go with your hybrid nuts?

 

[bubinga]

Years ago I bought a cheap bolt assortment and the 1/4-20 x 1" bolts have a 10mm head on them . Do you want some oddball bolts to go with your hybrid nuts?

Yes, I've seen all sorts of odd ball size drive.

Sent from my MotoG3 using Tapatalk

 

[bubinga]

I keep 1/4-20 nuts on hand with 3/8" and 1/2" as well as the USS standard 7/16" across the flats.

10mm is less than 0.020" larger than 3/8".

Yeah, maybe 3/8" with a sloppy tolerance.

Sent from my MotoG3 using Tapatalk

 

[APEowner]

Is it possible that the nuts are actually M6 x 0.75?

 

[PFSard]

Is it possible that the nuts are actually M6 x 0.75?

That was my first thought also. Here's a chart for the curious.

Pitch Conversions
Threads per inch, Pitch in inches, Pitch in mm
https://www.newmantools.com/tech/pitchconversions.htm

 

[sbosecker]

Is it possible that the nuts are actually M6 x 0.75?

That was my first thought also. Here's a chart for the curious.

Pitch Conversions
Threads per inch, Pitch in inches, Pitch in mm
https://www.newmantools.com/tech/pitchconversions.htm

OK...

If I'm reading that chart correctly I'd need to find a M6-1.25 (1.27 conversion) bolt to check out these odd nuts?

What say you?

I think M6-1.0 is the "standard"

Best regards,

Scott

 

[GRB]

Sounds like they aren't really 1/4x20 but actually M6x1.25

 

[sbosecker]

Sounds like they aren't really 1/4x20 but actually M6x1.25

GRB

Forgive me if the following comes off as bellicose but I don't know how else to ask the question...

Are you speculating that it is a M6-1.25 nut or have you personally seen a M6-1.25 nut threaded onto a 1/4-20 bolt?


Best regards,

Scott

 

[bigguns69]

Yes 1/4-20 will work with the metric equivalent. Fixed a lot of motorcycles when in a jam, this way. It is probably a metric fastener.

 

[rockwithjason]

the blanks fell into the wrong bin at the factory

 

[danielbuck]

sometimes odd stuff happens and slips through the cracks.

I remember once at an ace hardware they had a box of grade 8 1/2-20 bolts that would not thread on to any 1/2-20 nut. I returned the bolts only to realize in the store that the entire box of bolts was that way. The next box was fine.

 

[sbosecker]

A couple of weeks ago I ordered a couple of M6-1.25 machine screws to test the "It's A Metric Nut Theory".







They finally arrived today. It is worth pointing out that these screws - or the updated part number CCBB-2PB - are advertised as having M6-1.25 threads in multiple locations on the internet.


I opened the package and tried threading one of the mystery nuts onto one of these machine screws. I really thought it was going to work but the nut threaded onto the screw and then stopped...

...right at the same position it had stopped threading onto the M6-1.0 screw.

At first I was thinking, "Well, that's that I guess. It's a 1/4-20 thread and not metric." Then I realized how weird it was that it stopped threading onto the screws at the same place as the M6-1.0 screw.





I got my metric thread gage out and...

...for Pete's sake. These screws aren't a 1.25 pitch; they're a 1.0 pitch. No wonder they stopped threading at the same place as the M6-1.0 screws I had already tested the nut with.


Back to looking for another M6-1.25 screw to test the "It's A Metric Nut" theory.


Scott

 

[plinker]

I've run into some hardware that is 1/4 thread with a 10mm hex, mostly with some semi truck accessories (plastic fenders, IIRC) and cheap build it yourself type stuff.

 

[DFB]

Can't you like just go to a decent local hardware store or a tractor supply they usually have boxed inventory with assorted sizes. Makes life easy just as long as someone hasn't mixed up the parts in the little compartments.


Maybe I didn't read thru this well enough but if two nuts stopped at the same place on 2 different bolts my first thought would be is there a problem with nut's thread. Too bad you don't seem to have access to a thread chaser kit or tap and die set to easily assess the internal thread.

On a side note with "odd" fasteners I have one each the plastic boxes of assorted fasteners, nuts and bolts from the Harbor Frieght that I gleaned off my tool table and opened up to repair some pop up canopies, seems the fasteners often times fall out on people from transport or constant opening and closing. Anyhow I went to these boxes to see what I could discern with the different threads to relate to this post but was no 6 x1.25, just 8x1.25. But after looking thru them a bit then it turns out the heads on the #8 machine screws really didn't match anything. 11/32's was the closest fit but the tolerance was so loose still didn't seem right and probably would just barely work.

At least the thin heads mostly match all the cheapo fasteners you usually get with those different China products like carts and stuff you have to assemble

Keep us all in the loop with what you figure out

 

[vavet]

It is possible to have a sae thread and metric threads, or vice versa. Anything is possible with enough money or sufficient quantities.
I think it’s a cruel and unusual truck to play on the person who will eventually work on a given device.
I’ve seen it on bowling equipment where the equipment design hasn’t changed much in many decades, but it’s now a globally marketed piece of equipment. Sae tools are not readily available in all countries, so they keep using the same threads, but use a metric head.

 

[Millwrong]

They're M6X1.25 nuts... They'll thread onto a 1/4-20 fastener all day!

 

[Millwrong]

Back to looking for another M6-1.25 screw to test the "It's A Metric Nut" theory.


Scott

Just go to your vehicle and take out the first bolt you see with a 10mm hex on it, it'll be a M6X1.25....

 

[Kwikasfaki]

Have some 1/8 BSP (British std pipe thread) grease *******, "Zerks" with 10MM hex on them. Normally 3/16 Whitworth!