The National Nuclear Security Administration (NNSA) announced that it has completed the ‘diamond stamping’ of the new B61-13 nuclear bomb. This means that all requirements of the rigorous certification process have been met.
The U.S. National Nuclear Security Administration (NNSA) announced on June 8, 2026, “diamond stamping” for all canned subassemblies (CSA) of the new B61-13 gravity nuclear bomb. This milestone was achieved “three months ahead of schedule” at the Y12 National Security Complex located in Oak Ridge, Tennessee.
“‘Diamond stamping’ means that the weapon component has met all requirements of NNSA’s rigorous certification process and is of ‘war reserve’ quality and approved for deployment in the U.S. nuclear stockpile,” NNSA explained in a press release. This milestone also comes just over a year after Sandia National Laboratories (SNL) unveiled the first joint test assembly (JTA) of the B61-13 in March 2025 and the first completed bomb device in May 2025, a few months later.
NNSA explained that the CSA component of a modern two-stage thermonuclear weapon includes a second-stage capsule and “other components sealed (canned) within a thin metal container made of stainless steel or aluminum alloy.” This is coupled with the primary stage, which is the nuclear explosive package of the warhead.
🚨NNSA has completed “diamond stamping” of all B61-13 nuclear gravity bomb canister sub-assemblies (CSA) planned for this fiscal year, three months ahead of schedule @y12nsc.
This early milestone highlights our commitment to delivering on President Trump’s national goals… pic.twitter.com/BH90dCktTz
— NNSA (@NNSANews) July 8
The B61-13 has been described as “a modern variant of the B61 nuclear bomb, the longest-lasting and most versatile weapon in the United States’ nuclear stockpile.” The new bomb is designed to “destroy hard and deeply buried targets” and will be certified for delivery to the U.S. Air Force’s strategic bombers, including the new B-21 Raider.
The B61-12 Life Extension Program (LEP) and production of the new B61-13 are being carried out in a manner that does not change the number of nuclear gravity-dropped bombs in the U.S. inventory. As explained in our previous report on the LEP of the B61-12 in January 2025, the B61-13 will replace some of the B61-7s currently in the stockpile, and the number of B61-12s to be produced will be reduced by the number of B61-13s produced.
important milestone
In a press release, NNSA Administrator Brandon Williams said the progress of the B61-13 program demonstrates the nuclear security enterprise’s “ability to respond quickly and accurately to evolving geopolitical requirements.” “Completing the 2026 milestone ahead of schedule is a clear indicator of discipline and operational focus,” Williams said, adding, “It sends a message to our adversaries that our defense remains agile, secure and effective.”
Additionally, a separate update on SNL’s website reported 32 inert weapons flight tests across the nuclear triad. Among them were an “air-launched cruise missile test using the W80” and two B61-13 “Earth Penetrating Weapons” conducted at the Utah Test and Training Range.
It’s unclear whether the B61-13 was also drop tested, although the agency generally cited “flight and ground testing.” Additionally, the mention of the W80 warhead suggests testing of the W80-1 warhead for the AGM-86 air-launched cruise missile (ALCM) or the W80-4 warhead for the AGM-181 Long Range Stand Off (LRSO) missile.
B61-13
The B61-13 uses the warhead of the older B61-7 with a power range of 10 to 360 knots, but also features improved safety and accuracy mechanisms and improved components. The B61-13 will reportedly have both lower and higher yield options between 0.3 and 1.5 kt and 10 and 50 kt.
It was an honor to stamp the first completed B61-13 unit from @PantexPlant today!
These achievements signal to both our enemies and allies that America is ready to meet today’s environmental challenges from a position of strength and security. pic.twitter.com/1kgT3OF5Fa
— Secretary Chris Wright (@SecretaryWright) May 19, 2025
A special feature of the B61-13 is its ability to hit underground targets with “limited earth penetration capabilities through soft soils (…)”. Federation of American Scientists (FAS). The B61-13 can explode with “an explosive force equivalent to a surface-explosive weapon of more than 1 megaton” after hitting a buried target.
An F-35A flying at supersonic speeds conducted a drop test of the new B61-12 guided nuclear bomb. This is the first in a series of tests to certify that the F-35A can carry the B61-12. https://t.co/mM3yNVeGBE Approximately 480 B61-12s will be installed on US and NATO aircraft. pic.twitter.com/CzMAj8BO4p
— Hans Kristensen (also on Bluesky) (@nukestrat) November 23, 2020
Like the B61-12, the B61-13 undergoes rigorous stress, shock, pressure, vibration, shock and environmental immunity tests to evaluate whether the bomb and its individual components perform as planned. This includes firing from an SNL-operated Davis Gun into an 8-foot-deep swimming pool, forward ballistic impact testing on high-speed rail-mounted tracks, and finally testing on a variety of aircraft.
Currently, the B61-13 is only available on the B-21 Raider stealth bomber.
B61-12 Forward Ballistic Impact
Source: Sandhya pic.twitter.com/Sm1LRsy6oq— Casillic (@Casillic) November 10, 2023
Development of the new weapon was first revealed in October 2023. By March 2025, SNL unveiled the first Joint Test Assembly (JTA) of the B61-13. This is a test item without a live nuclear warhead for a variety of ground tests as well as airborne prisoner transport and separation tests.
In May 2025, NNSA announced that the first B61-13 nuclear bomb would be produced at the Pantex plant in Amarillo, Texas. This is “nearly a year ahead of the original target date and less than two years after the program was announced, making the bomb one of the fastest nuclear weapons produced since the Cold War,” the statement said.
B61-12 Forward Ballistic Impact
Source: Sandhya pic.twitter.com/Sm1LRsy6oq— Casillic (@Casillic) November 10, 2023
In its latest press release, NNSA emphasized: “The new variant features higher nuclear yields for destroying certain harder, larger-area military targets and provides additional flexibility in the President’s nuclear countermeasures options. The B61-13 is one of six ongoing warhead modernization programs NNSA is executing to ensure the long-term reliability and effectiveness of the U.S. nuclear weapons stockpile.”
