Is 3/16" machine screw equivalent to a #10? (2024)

dibbons said:

I need a tap to repair some damaged female threads that take a #10-32 machine screw. The employee at Home Depot helped me, but picked out a 3/16"-32 tap (Triumph brand). I had no idea these two items were the same. Can anyone verify this for me before I open the package? Thank you.

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Not the same

I've never heard of a 3/16" thread, under 1/4" they use the numbers...

Tap Chart UNC/UNF Threads - provides tap sizes, drill sizes, pitch, (threads per inch) basic major diameter, basic effective diameter, basic minor diameter of external threads, and basic minor diameter of internal threads for UNC/UNF threads

Daves69 said:

Take it back.

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What did I say???

krazykuda said:

What did I say???

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dibbons said:

Redfish seems to be saying they are "almost" the same, but he did not say take it back for some reason. According to my looking up #10 = .190" and 3/16 (doing the math) = .1875"

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I wouldn't take it back because of the few thousands difference. I would use it.
Even the correct tap or die is available in several types and grades. Send the wife shopping? Cut threads, formed threads, major, minor, pitch diameter tolerances, it can get very technical. The machinist hand book contains 100% of the related info ( and its a thick book! ) Add one of those and a few hundred dollars in measuring instruments to her shopping list? LOL
It would be nice to know where/what/when such a small bolt warrants soooo much concern.
Working on airplane engine or landing gear?

dibbons said:

I need a tap to repair some damaged female threads that take a #10-32 machine screw. The employee at Home Depot helped me, but picked out a 3/16"-32 tap (Triumph brand). I had no idea these two items were the same. Can anyone verify this for me before I open the package? Thank you.

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I just re-read the op's first sentence. You need a rethreader or a thread chaser. You may be asking for trouble using a tap to clean threads.

A tap will work fine for that, and I wouldn't worry about the difference in size, hand tapping will ream it out more than that, regardless.

That said, don't even think about this if it's a Chinese tap.

I've never seen a 3/16 tap, and it's kinda scary.

jos51700 said:

A tap will work fine for that, and I wouldn't worry about the difference in size, hand tapping will ream it out more than that, regardless.

That said, don't even think about this if it's a Chinese tap.

I've never seen a 3/16 tap, and it's kinda scary.

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Roger that! Good luck @dibbons and report back the results.

jos51700 said:

A tap will work fine for that, and I wouldn't worry about the difference in size, hand tapping will ream it out more than that, regardless.

That said, don't even think about this if it's a Chinese tap.

I've never seen a 3/16 tap, and it's kinda scary.

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The exact same #10 tap might be marked 3/16 inch for Lowes or Home Depot since the carpenter and most of those others mentioned in my previous post rely on a inch tape measure.
We can buy end wrenches marked both 5/16" and 8MM, 3/16" and 10MM, 3/4" and 19MM. None of those are exactly the same either.

RedFish said:

The exact same #10 tap might be marked 3/16 inch for Lowes or Home Depot since the carpenter and most of those others mentioned in my previous post rely on a inch tape measure.
We can buy end wrenches marked both 5/16" and 8MM, 3/16" and 10MM, 3/4" and 19MM. None of those are exactly the same either.

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I don't doubt it, it's just weird to me. I've seen wrenches marked 5/16" on one side and 8mm on the other but never taps

This screw and the threads it fits into are very important, they fit the factory style backlight louvers for a BBody and are hand made by Mike of Dayclona fame. During pre-fitting everything went together fine, now on installation day one screw is refusing to enter it's little threaded hole.

RedFish said:

( NOBODY will have the number size drills in stock )..

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Grainger or Production Tool Supply may have a set with them...

krazykuda said:

Grainger or Production Tool Supply may have a set with them...

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OK, Nobody in my neck of the woods. I'm sure the correct #10 tap can be found in a major city too.
Many of us are limited to Lowes, Home Depot, Ace/True Value, without a journey to the larger town.
If Harbor Freight has number drills, that's news to me. When I needed drills less than 1/16" ( .0625 ) I had to buy them online. Harbor Freight did not have. Nobody in my neck of the woods.

As for this no start thread.. I would first know for sure the start thread of the screw is not the problem. I've had this issue before with cheap mass produced hardware. ell I bought 3 knobs for cabinet doors and on of those screws had NO THREADS, still smooth shank like a clevis pin. Talk about pizzed off, boy was I ever. Anyway... Most times just chamfer that screw end a tad more would do.
If the female thread is the issue I would use the tap in hand to correct the first few threads. That's me though. You do what you feel is best. Good luck with it.

Bolt Depot - Machine Screw Diameter Table