The H designation is kind of strange. If you include it in your WPS, you have to use only filler metal that meets or exceeds the diffusable hydrogen limit of H4.

H4 has the following diffusable limit of 4mL of H2 per 100g of deposited weld metal (as you stated).

Unless the filler metal manufacturer puts that designation on the label of MTR, it is not certified to meet that designation.

If you have access to ASME Section II part C, there is some info in SFA 5.1 that addresses this.

The short answer is "No", if the H4 designation is not added, the diffusable hydrogen may be as high as 8.

The -1 designation refers to improved notch toughness and ductility properties.

Charles

Charles certainly answered your question.

I just had a comment about - "you talked to your suppliers...clueless..."

Is is just me or are the welding supply houses falling a bit short in tech oriented people these days? I have also used the words 'supplier" and "clueless" in the same sentance. Dating myself here but I remember calling my supplier(s) needing some 3/32" dia. E110T5K4. He would start rattling off all the different brands he had, tell me what gas to use..who is using what, "so and so" likes this brand...all the different features...etc, etc. Now when I call I get a long pause...then the person finally asks "ahhh do you have a part number?" i say "no...i just need 200 pounds of ANY E110T5K4 wire in 3/32" or 1/16" I don't care right now....do you have any?" A long pause, then "If you do not have the part number, I'll have to have someone call you back...AND I get the tone that i am stupid, because i do not have a part number!!"

I am sure that there are some really sharp sales people out there...and my hat is off to those houses that can keep the good sales guys/gals. It just seems to me that they are getting fewer and fewer.

Having said all that...if you need a copy of the SFA 5.1 pages that Chuck recommended above post me a fax # it is the least I can do to let me vent off your topic.