Undercut interpratation per TBL 6.1

Date 06-01-2007 21:49

I'm trying to understand this and having a little difficulty, probably because any undercut, to me, is unacceptable. Now, my opinion aside, for a statically loaded non tubular connection, 1" plate, table 6.1, 7(A) says that undercut "shall not exceed" 1/16" for any length of weld. Does this mean that for a 1" plate, any undercut, as long as its under 1/16", is acceptable? I would have a better grasp of the meaning if, at the begining of the paragraph it said "All material, regardless of thickness", but that isn't how it reads.
This is extremely ambiguous and makes it difficult to argue code-anybody have some insight they'd like to share?

By JA

Date 06-02-2007 13:14

believe it or not , i was wondering the same thing.......???????????????????????

now just sit back and wait........

By CWI555

Date 06-02-2007 20:05

I believe the intent is shown in the first sentence. Materials < 1" it's 1/32 max with the exception of
1/16" for any accumulated length up to 2" in any 12".

That means even for materials < 1" some length of <= 1/16" undercut is allowed, and when the plate is >= 1"
thickness range, any length of undercut <= 1/16" is allowed.

I don't see what is ambiguous about it. If you wish to discuss the matter with any given person, use logical test.

< 1" ? = up to 2" 1/16" in 12" of weld and 10" of 1/32" in the same 12". Else, if => 1"? =< 1/16" any length of weld.

It doesn't say all material regardless of thickness because that is not the intent.

Regards,
Gerald

By thirdeye (***)

Date 06-02-2007 20:19

waynekoe

Does this mean that for a 1" plate, any undercut, as long as its under 1/16", is acceptable?

Yes. Actually, undercut 1/16" deep would be acceptable as well.

~thirdeye~

By js55

Date 06-04-2007 18:08

In my manuals I have restricted undercut to 0 simply because there really is no reason for it to extist. It is just to easy to remedy. AND, it will be the first thing a customer sees. That and porosity which I also limit to 0 (by VT).
But from a code standpoint, it is important that they maintain a philosophy of mechanical viability and not visual aesthetics. This minimalist thinking I agree with.

By waynekoe (**)

Date 06-04-2007 19:21

I believe that my confusion was in the defination of a primary structural member, or, what constitutes a primary member, and boils down to my rejection of certain shop welded items. Thanks for the input.

By jon20013 (*****)

Date 06-04-2007 20:52

I believe depth of undercutting is dependent on the type of loading the structure will see in operations.