Lug nut size for SRL311

[Stan R]

Hello, I've lost a few lug nuts (no jokes please) and I'm having trouble discovering the correct size to replace them with. Some of these discussions have mentioned 7/16", I was under the impression they were 12 mm, so my quandary, what is the correct size and threads per inch or millimeter?? Raz in Indy, 70SRL311

[Fairlady66]

Might seem simple, but heck thats me, I think I would pull one off and take it down and have it matched up.

[It's a D-A-T-S-U-N]

Original lug nuts are 7/16"-20RH thread
Should be readily available @ the auto parts store, as I remember this size fit older GM vehicles.

[Stan R]

Might seem simple, but heck thats me, I think I would pull one off and take it down and have it matched up.

Thanks for the comment, I did take it to the local NAPA and they even had a small board set up to sample your bolt or nut for comparison . The 7/16 was a little sloppy as was the 12mm 1.5, they did not have a 1.25 pitch and at that time I was unaware of that pitch even being an option. I could only tell that those did not feel right. I even purchased a couple 12mm 1.5 pitch lug nuts and tried then out, felt a little loose and when it got to the really tight point it just slipped! Argh. I've now ordered some 1.25 pitch 12mm's and hope they fit correctly. Thanks for all the responses! Raz in Indy

[MTyler]

Should be 7/16-20, Do you have a pitch gauge?

[Stan R]

Should be 7/16-20, Do you have a pitch gauge?

No I don't have a pitch gauge...I was told 7/16 is for earlier cars, I'm not sure what year went to metric but was informed that my 70 is 12mm x 1.25 pitch. I'll find out any day now when the lug-nuts I ordered arrive, for sure the 12mm 1.5 pitch thread is wrong for my vehicle, as I said earlier they bite a little then spin, not good. I tried the 7/16 at the NAPA store and it felt loose, I could feel shake in the threads of the test bolt with one of my original lugs on it. I also took a spare lug bolt an it had the same effect when inserted into a 7/16 nut. So here I sit with my hobbled Dats waiting for my next order, hope its not on slow a boat from China. BTW- this is for Western mags so standard lugs won't work. Thanks for your input. Stan in Indy

[shifty]

I know that my '69 is 7/16's. I haven't heard before that they changed them for '70, but I could be wrong. Also possible that the wheel studs are messed up.

[Stan R]

I know that my '69 is 7/16's. I haven't heard before that they changed them for '70, but I could be wrong. Also possible that the wheel studs are messed up.

I'll post a note for the size they finally turn out to be. I'm probably running around in some sort of weird circle and will eventually come back around to the 7/16" and find out that my wheel studs are just wore out or something like that. That's usually how it works for me, it just can't ever be the first thing I try. Guess that's part of owning old cars.
Later! Stan in Indy

[Stan R]

I know that my '69 is 7/16's. I haven't heard before that they changed them for '70, but I could be wrong. Also possible that the wheel studs are messed up.

I'll post a note for the size they finally turn out to be. I'm probably running around in some sort of weird circle and will eventually come back around to the 7/16" and find out that my wheel studs are just wore out or something like that. That's usually how it works for me, it just can't ever be the first thing I try. Guess that's part of owning old cars.
Later! Stan in Indy

I guess I should have listened to the majority of people and not just the first person that responded to my inquiry. I won't mention his/her name, something like "DatsunDude" told me that the size was 12mm x 1.25 pitch. Well, after trying and buying a number of lugs that size and other metric sizes I finally found the correct size...7/16x20...argh. Thanks for everyone's inputs. Stan in Indy