The difference between Stud and Stud bolt. -( is it really correct to ask for "Stud Bolt"

[kulasera]

thread292-328339

Based on the above thread there were various answers given to differentiate the stud and stud bolt.

But if you engross clearly you can understand that the term "stud Bolt" defines that the requirement is either stud or Bolt is acceptable.

Since we already know the difference between the stud and bolt, I don’t what to define it again.

Because of the similarity in the mechanical properties, most of the places either can be used. So the engineer uses to ask for “stud bolt” in order to give choice of his/her requirement.

There are places where you cannot use bolts and you have to ask for stud. So in this case he/she will be asking "Stud"

But if you check the dimensional standard for Imperial Bolt and Stud, it’s entirely different - for Bolt it is ASME B18.2.1. For stud it is ASME B18.31.2 and hence the requirement should be very precise.

If anybody is having discrepancies in my comments, you are welcome to correct my statement.

Thanks
Kulasera

 

[LittleInch]

ASME B 16.5 (flange spec) defines them as "Machine bolt with nuts" (i.e. a bolt which includes a nut as a single item and one free rotating nut) or "Stud Bolt with nuts", i.e. a threaded stud with two free nuts. You are correct, the dimensions are different so you do need to decide which one you intend to use.

Most free flanges and flanged equipment I have seen use stud bolts. This is so that you can insert / remove the stud from either end and also that any damage or cracking of the interface between the flat end of the machine bolt end and the shaft is not present when you use two nuts. Often company specifications will ask for stud bolts to be used only.

Hence stud bolt means stud bolt, not either / or.

The dimensions and sizes are specified as a minimum in ASME B 16.5 for flanges.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[kulasera]

Thanks for explaining the difference between Stud Bolt & Bolt,

But when you refer the standard you have mentioned ASME B16.5 which is giving the recommended size (Stud Bolt Dia. and Length) of the Stud bolt to be used for the flange set.

When you deal with the vendors if we mention B16.5 he is correcting, that the dimensional standard for Stud Bolt is B18.31.2 and asking me to update the master data accordingly and I do also agree with him.

Because, there are some situation that the same studs can be used for some other purpose and hence mentioning the correct standard is more suitable than mentioning the recommended standard.

I appreciate your comments in this regards

Thanks
kulasera

 

[LittleInch]

Dimensional standard 18.31.2 refers to the actual studbolt itself (pitch, chamfer etc), but minimum length (many people add 10mm to give a spare thread), size (diam) and number per flange comes from ASME 16.5.

Just to confuse everything, in reality many people refer to "machine bolts" as just "bolts", but "stud bolts" should be called "stud bolts" to make sure you get what you really want.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way