M16 Threading

[Jayesh Shah]

Sir,
I am Machining a Nozzle for my Customer which have Threading on Side of M16 Internal Threading on
5different Places.
At the time of Enquiry Client have only Mention M16 Threading .
We have Supply the Product and now they are saying they required Threading According to G0 & No-Go
As it is Internal Thread we did use Tapping to do Threading .
So my Question is it Compulsory that client have to Inform Threading according to Go & No-go as they have not Mention Earlier .
If not then please Provide the Solution to Do Threading according to NO-GO

 

[3DDave]

Go and No-Go are two gages that are used to see if the thread has the correct pitch diameter. It is the least effort method to verify the thread is correct. I don't know what your contract says about inspecting and verifying the part.

 

[Tmoose]

Did the drawing call out a particular thread class, like something G or H ? It should have.
What is the thread class their GO/No Go gages will accept ?
Thread plug gages can only be used for the specific thread and tolerance stated on the gauge.
Normal tapped hole tolerance is ISO 2 (6H) .


Tapping hole tolerances
Tolerance class, tap​ Tolerance, internal thread (nut) Application​
ISO​ DIN​ ANSI/BS

ISO 1​ 4 H 3 B​ 4 H​ 5 H​ ​ ​ ​ Fit without allowance​
ISO 2​ 6H​ 2B​ 4 G​ 5 G​ 6 H​ ​ ​ Normal fit​​
ISO 3 6 G​ 1B​ ​ ​ 6 G​ 7 H​ 8 H​ it with large allowance​
-​ 7 G​ -​ ​ ​ ​ 7 G​ 8 G​ Loose fit for following treatment or coating​