Machined Thread in 6" Fasteners?
Machined Thread in 6" Fasteners?
(OP)
Hello All
Is it mandatory that the threads in a Stud (6" Dia) is required to be only rolled. Is Machining in CNC machine (Lathe)by cutting tool permitted.
If the manufacturer suggests machining then is it OK.
Is there any prohibition in ANSI/ASME B 1.1 or B 18.2 in this regard.
The Studs are being used in ASME Sec VIII Div 2 vessels and Div 1 Vessels.
Is it mandatory that the threads in a Stud (6" Dia) is required to be only rolled. Is Machining in CNC machine (Lathe)by cutting tool permitted.
If the manufacturer suggests machining then is it OK.
Is there any prohibition in ANSI/ASME B 1.1 or B 18.2 in this regard.
The Studs are being used in ASME Sec VIII Div 2 vessels and Div 1 Vessels.





RE: Machined Thread in 6" Fasteners?
From the supply side currently all studs of this size are called out as single point threads. Not all are 60°point as there are some special thread profiles called out by certain end users.
The largest stud currently available with rolled threads is 4" and it an expensive special.
Just a little reminder that you are in a new world when it come to properly tighteneing fasteners of this diameter.
RE: Machined Thread in 6" Fasteners?
high tensile steel bars 10 Metres long. Awesome sight, 700 kgs+ per stud! - client is using the studs in a bridge construction and the follow up may be M125 -6mm pitch!
So it can be done.
RE: Machined Thread in 6" Fasteners?
None of the B 18.2 series deals with studs.
IFI-136 appears to allow either rolled or "threads produced by other methods" in some sections. However, in the section dealing with threads for "Pressure-Temperature Piping" the method of manufacture is not discussed. That section also refers to ASME B16.5, which I do not have ready access to.