Post-Manufacturing Conformance Testing

What to do when the manufacturer’s testing does not meet the distributor’s customer specs.

At times, the testing done by the filler metal manufacturer does not meet the needs of a distributor’s customer. This can happen as a result of mismatched specifications and is usually customer driven. Having a good understanding of where gaps in testing requirements exist and how to close that gap can help distributors close the sale.

A welding distributor’s customer needed a conformance test report for a specific heat of welding filler wire that was in the distributor’s stock, but the manufacturer of the wire could only provide a certificate of conformance for the product classification, not for that specific heat. It became clear that there is sometimes a gap between the conformance testing that is performed by the filler metal manufacturers and the material performance specifications that the consumers of welding filler metal need, often with the distributor caught in the middle.

The goal of this article is to help welding filler metal distributors understand some of the key differences between filler metal certification requirements (i.e. AWS A5.xx) and filler metal consumer’s fabrication specification requirements (i.e. AWS D1.1), why there sometimes can be a mismatch, and actions a distributor can take to bridge the gap and close the sale.

Wire Classification

Specifications call out requirements for packaging, spooling and labeling, including the specific classification of the wire.

AWS A5.xx Welding Filler Metal Specifications
There are approximately 30 AWS A5.xx specifications that prescribe manufacturing and testing requirements for classifying welding filler metals and allied materials. Each specification covers a material category like carbon steel, stainless steel, nickel-based alloys or aluminum, and is generally specific to a welding process. The specifications were written by committees made up of both filler metal manufacturers and consumers in an effort to balance the needs of both. The testing requirements and minimum/maximum acceptable values are intended to meet the requirements for general structural applications where a particular filler metal is likely to be used. The testing usually consists of tensile, bend, charpy V notch (CVN), metallurgical analysis, coating moisture, diffusible hydrogen and/or chemical analysis of the welded material or sometimes of the filler metal itself. The specifications also call out requirements for packaging, spooling and labeling, including the specific classification of the wire

Additional Filler Metal Specifications
Some industries and/or countries have their own filler metal specifications, like the Canadian Welding Bureau (CWB), American Bureau of Shipping (ABS), Det Norske Veritas (DNV) and Lloyd’s Register. Military specifications are also written for filler metals that will be used in military applications. For example, MIL-E-24403/A (SH) is for carbon steel flux cored electrodes. These specifications have testing that is generally similar to AWS A5.xx requirements, but can be tailored for a specific application like shipbuilding. In addition, most of these specifications require an auditor to be present during the testing process and have annual re-certification requirements.

While there is no governing body or law in the United States that requires conformance with the filler metal specifications, very few consumers would purchase a product that does not have a certification to one of the standards mentioned above.

Certificate of Conformance – Product Specific vs. Lot Specific
Frequency of testing (i.e., annually, every lot, every heat, etc.) is not called out in the AWS A5.xx specifications. However, other specifications like AWS B2.1 Schedule J require that every lot produced be tested. The wire manufacturer’s quality system ultimately determines the product testing frequency. This means that unless specifically requested, not every heat or lot of filler metal produced will be conformance tested as long as it is manufactured using the same processing conditions and raw materials. A certificate of conformance for the product gives representative test results for the product, but not necessarily for each lot. This can be especially true for products that are made in large volumes, like ER70S-6.

Crack Tip Opening Displacement

Crack Tip Opening Displacement (CTOD) testing is becoming a standard test for many applications used in oil and gas and is not addressed in the AWS A5.xx specifications.

Fabricator Specifications
Fabricator specifications like AWS D1.1, ASME IX and military specifications like NAVSEA S9074-AQ-GIB-010/248 provide weld qualification criteria that will meet or exceed the requirements for a particular fabrication joint design. They generally call out a wire classification that is required, and any required testing is for the joint, the welding process and/or the welder, not for the filler metal.

In addition, individual company specifications will provide additional qualification criteria that use specifications like AWS D1.1 or ASME as a baseline. Generally, the more critical the application, the more stringent the testing requirements will be—including conformance testing of the consumables used in the welding process. An example is Crack Tip Opening Displacement (CTOD) testing for the oil and gas industry. This test is becoming a standard test for many applications used in oil and gas and is not addressed in the AWS A5.xx specifications.

Distributors Caught in the Middle
The problem for distributors is that the filler metal and fabricator specification requirements don’t always match up. Distributors can find themselves in an awkward position of having customers who need a product that has been tested at the heat or lot level but no inventory that matches. This can result in a distributor’s customer looking for test results on a welding wire that has not been produced.

A similar situation can come from dated product. Due to the potential for moisture pickup, sometimes stick electrode, welding flux and cored wire manufacturers will limit their liability by only guaranteeing a product for a certain period of time. This can result in a product losing its certification because it sat on the shelf for too long.

Private labeling can also cause issues. A wholesaler who has product that has been manufactured by someone else and private labeled may want to protect their client information. Thus, the wholesaler may not want to ask the manufacturer of the wire for conformance testing.

The problem for distributors is that the filler metal and fabricator specification requirements don’t always match up.

Post-Manufacturing Conformance Testing
Testing (or re-testing) of the welding filler metal can be performed at any time to prove conformance. All that is needed is the appropriate specification or customer requirements. A commercial testing lab specializing in welding consumable conformance testing can coordinate all of the welding, testing and reporting that is required. When it comes time to have additional conformance testing done on a welding product, there are some things to look for in a testing provider:

• Understanding various filler metal specifications — Performing mechanical testing is tricky business, but the best mechanical test performed incorrectly against a welding specification is worthless. The testing provider should have intimate knowledge of filler metal and fabrication specifications to ensure conformance testing is done correctly.

• Welders capable of passing conformance tests — Not surprisingly, the filler wire specifications can be more rigorous than fabricator specifications. Welder skill (or lack thereof) can wreak havoc on a conformance test. Having welders who routinely perform conformance tests for filler wires can help ensure the testing is done correctly.

• A functioning quality system — At minimum, the testing provider should have ISO 9001 certification. Even better is ISO 17025. ISO 9001 allows the testing provider to write their own procedures for testing which should follow the ASTM or other appropriate testing specifications. ISO 17025 is significantly more stringent and requires the test lab to prove the standard is followed. There are also industry-specific quality requirements like NADCAP for aerospace applications.

• One-stop shop — A testing lab with the capability to perform all of the critical steps required for conformance testing will generally allow for faster results due to the ability to control schedule. At minimum, a testing provider should have machining and mechanical testing capabilities, but an ideal situation would be to have welding, machining, radiographic testing, mechanical testing, metallurgical analysis and chemical analysis capabilities all under one roof.

Engineering expertise — Having knowledgeable engineering staff with expertise in welding and testing can be an invaluable resource when test results are out of specification.

Effect of Welding Parameters on Test Results
It is important to note that consumable selection and welding parameters play a critical role in both filler wire conformance testing and fabricator specification testing. The choice of welding parameters can significantly influence the test results. It is important that any testing be performed at welding parameters representative of those that will be be used during fabrication.

Gases and Welding Distributors Association
Andy Joseph Andy Joseph is director of lab services for Edison Welding Institute (EWI), located in Columbus, Ohio, and on the Web at