Properties for ASTM A193 B7H?? 1

[Tango635]

Hi folks,

Anyone know if this material is covered in the standard? I have been searching my reference books and internet and find reference to ASTM A193 B7 & B7M, but not B7H? If this is covered, I would be willing to purchase the standard. Just would like to know if it's in there before spending the money.

Thanks for your help.

PS. would appreciate any notes/comments on why it might be recommended over B7.

 

[HgTX]

It doesn't look like B7H has ever been an official ASTM A 193 grade. It wasn't there in 1966, 1986, or 1999, and it isn't there now.

Hg

Eng-Tips policies: faq731-376

 

[rneill]

There is no grade B7H in ASTM A193 so it doesn't exist. In what context did you come across a reference to it ?

 

[Tango635]

My application:
The B7H designation is stamped on the end of some studs that we were going to install on a reactor that has H2S in the process. Instead, we are going with B7M studs. We have had these studs here for a while. Will have to back-track and find out where we got them and maybe supplier can provide some information/specs.

Someone elses application:
Smith Valve's "Alloy Steel API trim 8" gate valve. The gland studs (item 11) are B7H supposedly. See Link....

http://www.smithvalve.com/technical/standard-bills-material.aspx

With your comments that B7H doesn't exist (and I agree with you) I am pretty confident that B7M is the correct material to use so finding out what B7H is, is just a curiosity thing. I appreciate the help guys. Thanks for the info.

 

[rneill]

Pretty sure the B7H on the Smith site is just a typo, but can't explain why the stud would be Stamped B7H since this marking is not consistent with A193.

I would reject these studs and replace with B7M noting that B7M does have lower allowables than typical B7 so you would want to verify the flange design with these.

 

[Tango635]

Well???, I asked for a stud to be brought to me. Could not wait to see this stud of mystery material B7H. It turns out that it is stamped B7 with an HT above it. HT as in Higland Threads, Inc. Link...

http://highlandthreads.com/default.asp?RETURN=True

Still a good catch though. B7M is the correct material to use.

Sorry for the head scratching questions guys. He, he.

 

[rneill]

Do keep in mind the warning that B7 are considered high strength studs whereas B7M are considered intermediate strength studs so you can be changing things and may want to consider a detailed evaluation to confirm this is okay.