AMS 6931D: What You Need to Know

In December 2017, SAE released an updated and much-needed version of AMS 6931. Before we dig into some major changes in AMS 6931D, let’s take a look at where AMS 6931C left off.

AMS 6931 is a specification for titanium bar, forgings, and forging stock. AMS 6931 is specific to the 6AL-4V alloy.

AMS 6931C covered products up to 6” in diameter or least distance between parallel sides. However, it is commonly requested for products larger than 6” to be certified to AMS 6931. Since larger sizes were not specifically covered in the specification, AMS 6931C left it up to the purchaser and producer to determine what mechanical requirements could be satisfied for any products outside of the range identified in the specification. Usually manufacturers interpreted this as either (1) product manufactured in a size outside of the range of AMS 6931C would be manufactured to meet the properties of the largest size that is covered, or (2) since there are no specific requirements for products outside of the range of the specification, test results would be for information only, and not cause for rejection.

AMS 6931D recognizes that purchasers and end users are looking for assurances of what mechanical properties can be achieved in larger section sizes, by extending the coverage to 10” in diameter or least distance between parallel sides.  Also, while AMS 6931C defined properties for products with a maximum cross-section of 48 square inches, AMS 6931D extends to 79 square inches.  This allows titanium AMS 6931D products in this extended range to be certified without a “for information only” caveat; we now have firm requirements. For products larger than 10” diameter or least distance between parallel sides, and beyond a 79 square inch cross-section, the spec still does mandate the purchaser and producer to agree on the properties. [Read more…]

AMS 4928W: What You Need to Know

In December 2017, SAE released an updated and much-needed version of AMS 4928. Before we dig into some major changes in AMS 4928W, let’s take a look at where AMS 4928V left off.

AMS 4928 is a specification for titanium bar, wire, forgings, flash-welded rings, and drawn shapes. AMS 4928 is specific to the 6AL-4V alloy.

AMS 4928V covered products up to 6” in diameter or least distance between parallel sides. However, it is commonly requested for products larger than 6” to be certified to AMS 4928. Since larger sizes were not specifically covered in the specification, AMS 4928V left it up to the purchaser and producer to determine what mechanical requirements could be satisfied for any products outside of the range identified in the specification. Usually manufacturers interpreted this as either (1) product manufactured in a size outside of the range of AMS 4928V would be manufactured to meet the properties of the largest size that is covered, or (2) since there are no specific requirements for products outside of the range of the specification, test results would be for information only, and not cause for rejection.

AMS 4928W recognizes that purchasers and end users are looking for assurances of what mechanical properties can be achieved in larger section sizes, by extending the coverage to 10” in diameter or least distance between parallel sides.  This allows titanium AMS 4928W products in this extended range to be certified without a “for information only” caveat; we now have firm requirements. For products larger than 10” diameter or least distance between parallel sides, the spec still does mandate the purchaser and producer to agree on the properties. [Read more…]

Understanding Specification MIL-T-9047 – Which Grade Do You Really Need?

MIL-T-9047 is a classic titanium specification covering aircraft quality Titanium and Titanium Alloy Bars (Rolled or Forged) and Reforging Stock.  It was cancelled in 2005 but it is so ingrained in the titanium industry, it seems it will never truly go away. This specification tends to be confusing to users, because it covers so many different types of titanium and different conditions. Rather than calling out an alloy, an old drawing may call out just a Type or a Composition.  We hope the following table will aid you in procuring the right type of titanium for your requirements.

The above table appears in the back of MIL-T-9047G (available for free download at http://quicksearch.dla.mil/qsSearch.aspx), but we like our version better. If you agree, you are welcome to email us at sales@performancetitanium.com and we will gladly share a copy.

Specification MIL-T-9047 was cancelled in February 2005. The last active revision was “G”. In the cancellation notice, future acquisition was directed to SAE AMS-T-9047, which is also now cancelled. If your contract requires use of the superseding specification, refer to this discussion for help.

Since the MIL-T-9047 specification has been used for decades, often times a drawing will call out an old Composition such as MIL-T-9047 Comp 6. Using the table above, we can determine that Comp. 6 is related to the alloy 6Al-4V, and the drawing is pulling from an older revision of the specification, either Revision D or F. It is unusual to procure material whose certifications will still use these older revisions, types and compositions. The certs will most likely display this alloy as 6AL-4V, MIL-T-9047G (the most recent revision of the cancelled specification).  Check with your Sales Rep if you have questions or reach us at Sales@performancetitanium.com.

Understanding MIL/AMS-T-9047 Supersession

In the early 1990’s, US Secretary of Defense, William J. Perry, was at the forefront of military specification reform. Perry encouraged the military to use Non-Government Standards and do away with outdated military specifications, asserting that doing so would reduce government oversight and lower costs.

This reform had a significant effect on one of the most common specifications used in titanium procurement: MIL-T-9047.  This specification covers aircraft quality, commercially pure and alloyed titanium rolled/forged bar, and reforging stock products.

In February 2005, MIL-T-9047G Amendment 2 was cancelled, and superseded by SAE (Society of Automotive Engineers) AMS-T-9047.  AMS-T-9047 was a word-for-word translation of MIL-T-9047G AM.2, with minor editorial and format changes. AMS-T-9047 covered 16 grades of titanium, and multiple conditions, like its predecessor MIL-T-9047 did. SAE noted that the specification was too complex and would be better utilized if each spec and condition was broken out into its own AMS spec. In May 2006, AMS-T-9047A was cancelled and superseded by various specifications.

Many contracts still call out MIL-T-9047 and AMS-T-9047, and they continue to be certified by manufacturers.  If your contract requires use of the superseding specification, refer to the table below pointing to the Superseding Specifications for several material designations within AMS-T-9047.

If you would like help determining which grade or specification you need, give us a call at 888-772-8984 or email sales@performancetitanium.com and we can help.

AS6279 – What You Need to Know

On October 15, 2015, a new specification called AS6279, “Standard Practice for Production, Distribution, and Procurement of Metal Stock” went into effect. AS6279 adds several new responsibilities related to chain of custody, traceability, certifications, record retention, product substitutions, and dimensional limits.

If you supply or purchase materials to specifications such as AMS 4900, AMS 4901, AMS 4911, AMS 4919, AMS 4928, AMS 4930, AMS 4965, AMS 4967, AMS 4971, AMS 4978, AMS 6930, AMS 6931, AMS 6932, AMS 6936, you are affected. Additional specifications will begin to incorporate AS6279 as they are revised.

AS9100/AS9120 Certification: Perhaps the most significant requirement is that producers and distributors of titanium being sold to the above specifications, must be accredited to AS9100 or AS9120, unless otherwise approved by the cognizant engineering organization.

Definition of “Producer”: AS6279 establishes that any organization can become a “Producer” by coordinating manufacturing operations, even if that organization does not perform any processes in-house. An organization authorizing processes that change material gauge, condition, or specification, is a Producer. Producers are responsible for ensuring that material meets all specification requirements for the new dimension, condition, or specification. Producers are required to identify themselves and provide information about manufactured products to MMPDS (Metallic Materials Properties Development and Standardization), which is used to analyze design allowables for aerospace structural designs.

Product Substitutions: It is not appropriate to substitute product forms without authorization from the cognizant engineering organization. Plate and flat bar may look similar, but the inherent product characteristics are different. Organizations must also ensure the thickness or Short Transverse dimension is not cut to achieve desired thickness, without authorization from the cognizant engineering organization.

Chemical Milling: Chemical milling or pickling shall only be used for alpha case removal or pre-penetrant etch, unless approved by cognizant engineering organization.

Ordering Information: Aside from standard ordering information, purchasers must ensure that any relevant requirements are flowed down from the cognizant engineering organization. Include requirements for grain direction, as well as maximum allowable gauge. When the size being ordered exceeds the range covered by the AMS specification, purchasers must flow down any mechanical property requirements or supplemental tests that must be satisfied.

Free introductory training presentations are available at: http://www.sae.org/servlets/works/committeeHome.do?comtID=TEAAMSMGC

AS6279 is available for purchase through SAE International: http://standards.sae.org/as6279/

Understanding MIL/AMS-T-9046 Supersession

In the early 1990’s, US Secretary of Defense, William J. Perry, was at the forefront of military specification reform. Perry encouraged the military to use Non-Government Standards and do away with outdated military specifications, asserting that doing so would reduce government oversight and lower costs.

In September 1999, MIL-T-9046J was cancelled, and superseded by SAE AMS-T-9046. AMS-T-9046 was a word-for-word translation of MIL-T-9046J Amendment 2, with minor editorial and format changes. Unfortunately, AMS-T-9046 still covered nearly 20 grades of titanium and multiple conditions, rendering it somewhat complicated for users. In May 2006, AMS-T-9046 was cancelled as well, referring future procurement for each alloy and condition to a separate AMS specification.

If your contract requires use of the superseding specification, refer to the table below pointing to the Superseding Specifications for several material designations within AMS-T-9046.

Still not sure which grade or specification you need? Give us a call at 888-772-8984 or email sales@performancetitanium.com and we can help.

Understanding Specification MIL-T-9046 – Which Grade Do You Really Need?

Back in 1955, specification MIL-T-9046 was born, covering Titanium Sheet, Strip, and Plate. This specification tends to cause a lot of confusion for clients because it covers nearly 20 different types of titanium, and several conditions within some of the alloys. On top of that, during several revisions of the spec, a new alloy designation code was given to each type. We hope the following table and discussion helps to ensure procurement of the right type of titanium for your requirements.

The above table appears in the back of MIL-T-9046J (available for free download at http://assist.dla.mil), but we like our version better. *If you agree, you are welcome to email us at sales@performancetitanium.com and we will gladly share a copy.

Back to the good stuff. Specification MIL-T-9046 was cancelled in September 1999. Its last active revision was “J”, and the code designations for that revision are featured in the far right column of the above table. In the MIL-T-9046 cancellation notice, future acquisition was directed to SAE AMS-T-9046, which is also now cancelled. If your contract requires use of the superseding specification, refer to this discussion for help.

Since the MIL-T-9046 specification has been used for decades, often times a drawing will call out an old code such as “MIL-T-9046 Type 3 Comp C”. Using the table above, we can determine that “Type 3 Comp C” means the requirement is for 6Al-4V, and the drawing is pulling from an older revision of the specification, either Revision F or H. These days, it is unusual to procure material whose certifications will still use older revisions. Certifications would most likely display this requirement as “MIL-T-9046J AB-1”. Check with your Sales Rep if you have questions.

The code designations for Commercially Pure grades of titanium were established in the most unfortunate fashion. Under MIL-T-9046 Revision J, Commercially Pure Grade 1 titanium would now be referred to as “CP-4”, Commercially Pure Grade 2 titanium became “CP-3”, Commercially Pure Grade 3 titanium became “CP-2” and Commercially Pure Grade 4 titanium became “CP-1”. If you are unsure which grade you require, please contact us for help. Although the names sound similar, the differences between the grades are significant.

PERFORMANCE TITANIUM GROUP: A CUT ABOVE THE REST