FAIL of the day

Quote:

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Originally Posted by 408.Luke

first off i think i know how to drill and tape a hole every one has there off days, second i did use a smaller bit..... and thirdly i need the hole gone lol notice how the second one i made worked fine

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you may know how to drill and tape, but you forgot how to spell tap..........:point: just f'n with ya, bud

:lol:

I has a fews funny thingies to say but since my FIL's manufacturing and machine shop died in Oct along with my secondary income I stays mouth shutted on this un.

pm me then im up for some constructive criticism :lol:

Sorry Luke. My comment above was more directed to the other guy trying to explain things that may not have been needed to be explained.

Not a problem nathan

Quote:

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Originally Posted by GasGuzzler

Sorry Luke. My comment above was more directed to the other guy trying to explain things that may not have been needed to be explained.

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I must be in deep doo doo. :cowl:

I was just trying to help. :sorry:

If we are talking about a 3/8 NPT tap this is what I understand.

The correct drill size is .5676" close to 9/16" .5625" but that is for "steel, wrought iron, or brass " . I looked but could not find what is called out for aluminum.
[Machinery's Handbook 26 ]. That is why I use a smaller drill bit because aluminum is so soft.

If it is a NPS or NPSF [straight threads ]then you would use a 37/64" drill.

A NPT thread seals on the threads, not on the shoulder of the fitting. It looks like the fitting is too deep and setting on it's shoulder. If --it tightened up right at that point you would have the strongest fit.

3/8" NPT should have .240" of threads engagement by hand tightening with another .1667" or about 3 turns with a wrench. I understand that with a thin cover it would be easy to go too deep and resting on the shoulder before the threads got tight.

It just looks like the tap was run in too deep on the second hole. On the first hole --- I hate that drill wobble.

Tell me where I am wrong I am not too old too learn.
:beerchug:

none of that is wrong just sayin i know what im doin

and now it gets interesting....:popcorn:

Quote:

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Originally Posted by metalchips

I must be in deep doo doo. :cowl:

I was just trying to help. :sorry:

If we are talking about a 3/8 NPT tap this is what I understand.

The correct drill size is .5676" close to 9/16" .5625" but that is for "steel, wrought iron, or brass " . I looked but could not find what is called out for aluminum.
[Machinery's Handbook 26 ]. That is why I use a smaller drill bit because aluminum is so soft.

If it is a NPS or NPSF [straight threads ]then you would use a 37/64" drill.

A NPT thread seals on the threads, not on the shoulder of the fitting. It looks like the fitting is too deep and setting on it's shoulder. If --it tightened up right at that point you would have the strongest fit.

3/8" NPT should have .240" of threads engagement by hand tightening with another .1667" or about 3 turns with a wrench. I understand that with a thin cover it would be easy to go too deep and resting on the shoulder before the threads got tight.

It just looks like the tap was run in too deep on the second hole. On the first hole --- I hate that drill wobble.

Tell me where I am wrong I am not too old too learn.
:beerchug:

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ignore em,hes slightly ocd :LOL: jfwy GG