# Answer to a hardware headache 5/16-20 nut?



## Elgin Baylor

Please forgive me if I'm stating the obvious, or if this issue has been beat to death.

While I was working on my vintage balloon tire bike the other day I needed a nut. I thought, no problem, I have an ample supply of misc. hardware. After all it was just a 5/16" nut, right...
After not being able to match it, I pulled out the thread gauge. 5/16-20, no problem, or so I thought. 5/16-18 is standard, but 5/16-20 is an oddball... After some head scratching, I turned to Google. Apparently I'm not the first person to run into this problem. Well, it turns out that an M8 x 1.25 pitch metric nut fits perfectly. These are readily available from McMaster-Carr:
# 90592A022 (Metric Plain Steel Hex Nut, Class 8, M8 Size, 1.25MM Pitch, 13MM W, 6.5MM H, Packs of 100) $4.51
# 91828A410 (Metric 18-8 Stainless Steel Hex Nut, M8 Size, 1.25MM Pitch, 13MM Width, 6.5MM Height, Packs of 50) $9.98
# 94000A039 (Metric 18-8 Stainless Steel Acorn Nut, M8 Size, 1.25MM Pitch, 13MM Width, 15MM Height, Packs of 10) $5.66
I hope this saves someone some time.


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## pelletman

I measured a 5/16-22 thread today on an 1880's Gormully & Jeffrey..  That won't be easy to find a tap or die for..


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## frankster41

*Odd size hardware*

That is where a lathe comes in handy. frankster41


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## Andrew Gorman

I love this 21st Century:
http://drillsandcutters.com/qualtec...special.aspx?gclid=CP-cl5KepbMCFQ6CQgodGg0Acg

5/16"-22 HSS Taper Tap, Special Thread In Stock!


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## Larmo63

*Make them your self....*

Before de-burring....


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## pelletman

Wow, thanks Andrew!  I don't need it but that is a good resource!


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