Welding Tips and Tricks

Hey guys,

I have a welding certification coming up in a couple of weeks with my employer. The first part of the

test will be 3/8 plate 60 degree including angle, 1/4 backing plate with 1/8" root opening, in the vertical up position.

My test instructors are pre-tacking all of the test pieces for us, and I was wondering if the 1/8" root opening was

allowable per code. Anytime I have ever seen this test done, it has always had a 1/4" root opening.

Welcome to the forum calebgee.

The root gap is supposed to be 1/4" if the groove angle is 45*, or 3/8" if the groove angle is 30* and 1/2" if the groove angle is 20*. 60* groove angle (30* bevel angle) and 1/8" root opening is commonly used for open root welds but usually with a 1/8" root face (land).

With that narrow opening I would weld the root pass with a 3/32" electrode if it is allowed.

All the D1.1 backer bar tests I have taken have had a 1/4" root gap so I also find that one a bit odd.

Thanks for the replies everybody, I start testing next Monday. Seems to be that with a 60* included angle, 1/8" root opening seems to be the norm. This is only one test out of many that I will be taking next week. I'll keep everybody posted.

calebgee wrote:Thanks for the replies everybody, I start testing next Monday. Seems to be that with a 60* included angle, 1/8" root opening seems to be the norm. This is only one test out of many that I will be taking next week. I'll keep everybody posted.

I looked up the specs on a D1.1 in the 3G SMAW. I was going to take a pic but not allowed per copyright. It specifically shows a 1/4" root opening. I am not saying that the 1/8" is completely wrong, but I would be afraid of lack of fusion or possible slag entrapment. I agree on the 3/32" rod for a root, think this is your best bet. I just took a D1.1 in MIG and had the 1/4" root with backer. It is true that most pipe gaps are 1/8", but this is open also. The best of luck on the test and get us some pictures of your success!
-Jonathan

Theres no variance in that 1/4" eh? Most of the specs I've seen are like 1/8" gap plus or minus anywhere from a 1/32 to a 1/16". But that's pipe not plate :/

kermdawg wrote:Theres no variance in that 1/4" eh? Most of the specs I've seen are like 1/8" gap plus or minus anywhere from a 1/32 to a 1/16". But that's pipe not plate :/

I will have to look again tomorrow to be sure on the variance. I would think it could very at least 1/32"-1/6".
-Jonathan

There is no variance listed in the code book because it has a backing bar. Open root welding leaves some room for the welder to adjust things to their preference such as root face and root gap.

I looked, it is 1/4" and no mention of variance, just to back up lazerbeam. I still don't understand why they choose 1/8" but I guess it does not matter as long as you pass.
-Jonathan

I suppose the caveat here, is this may be a qualification test for a WPS based on AWS D1.1, rather than an actual certification.

The other option is the guy who wrote the qualification parameters was working from (faulty) memory.

I'd have to dig more than I care to, to discover the variances allowed in WPSs that still meet D1.1. Even when D1.1 was my governing code, I only "qualified" (tested), and did what "they" said do. I did not "certify", so all I knew of the code at the time was what was expected in my particular test.

Steve S

Otto Nobedder wrote:I suppose the caveat here, is this may be a qualification test for a WPS based on AWS D1.1, rather than an actual certification.

The other option is the guy who wrote the qualification parameters was working from (faulty) memory.

I'd have to dig more than I care to, to discover the variances allowed in WPSs that still meet D1.1. Even when D1.1 was my governing code, I only "qualified" (tested), and did what "they" said do. I did not "certify", so all I knew of the code at the time was what was expected in my particular test.

Steve S

You bring up a good point between "qualified" and "certified" Otto. You can be qualified to do something, but not certified. You can be certified to do something, but not qualified. It's the rare craftsman that is both these days.