# Southbend 9 spindle threads



## jocat54 (Mar 26, 2013)

I want to make a thread protector for my SB 9 spindle (1 1/2 x 8) and I am having a senior moment....what size hole should I bore for threading the protector? I tried measuring but not thrilled with the results. All the charts I found so far don't list 1 1/2x8 just 1 1/2x6 or 1 1/2x12. This will be an aluminum protector.....boring the hole is going to take a while, the biggest drill bit I have is 3/4".

Thanks,
John


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## atwatterkent (Mar 26, 2013)

There are formulas for finding the recommended bore but in your case I'd say "measure the ID of the thread on your chuck or faceplate." Another option is to just use your dog driver. It'll do the same job.


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## jocat54 (Mar 26, 2013)

Never mind, I found the formula.
1/ by threads (8)=.125
1.5 minus .125=1.375 hole  (approx 75%)


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