Neck Flex® Harness Holds 1,461 Pounds in NC State Lab Test; Company Issues First Lab-Tested Neck Harness Load Rating

Independent university test: stitching never failed, steel bent first. Harnesses rated to lift, swing and twist 300 lb against a 1,461-lb break strength.

LEESBURG, VA, UNITED STATES, October 5, 2026 /EINPresswire.com/ — Gonza LLC, maker of the Neck Flex^® neck training harness, today published the results of independent tensile testing by the Physical Testing Laboratory at North Carolina State University’s Wilson College of Textiles and issued what the company describes as the first laboratory-tested load rating for a neck training harness. Its MMB Pro Series and Ballistic Kevlar^® Series harnesses are rated to a working weight of 300 pounds (136 kg): weight that can be lifted, swung, jerked, dropped and twisted in training while the harness stays far below the 1,461 pounds of force its fabric and seams withstood in the laboratory.

In sixteen pulls on an MTS Criterion Model 43 tensile machine, the harness fabric held between 1,156 and 1,227 pounds of force (lbf), the padded seam assemblies held between 1,179 and 1,461 lbf, and the welded steel D-rings that carry the loading chain opened at between 819 and 937 lbf. The lowest value recorded anywhere on either harness was 749 lbf, the equivalent of sixteen Olympic 45-pound plates hanging from a single ring. The full report, with every replicate and failure photograph, is published at https://www.theneckflex.com.

Testing followed a modified ASTM D5035 strip method with a 10 kN load cell, with three specimens cut from each of three locations on each harness: the plain fabric, the padded seam assembly, and the D-ring loading point. The lab issued its final report on October 2, 2026.

Three findings stand out. In every seam test on both harnesses, the fabric tore at the seam line while the stitching held. At every D-ring loading point, the welded steel ring opened with the webbing and stitching intact. And on the second D-ring pull of the MMB Pro, the laboratory’s hardened steel hook fixture fractured before the harness did.

The rating is derived from the test data. A neck harness is loaded through its two D-rings, so the loading chain shares the weight between them. The weakest ring held 749 lbf, so two rings together carry approximately 1,500 lbf before the steel bends. Working weight is weight in motion rather than weight hung still: a 300-pound working-weight rating means 300 pounds can be lifted, swung, jerked, dropped and twisted on the harness while four-fifths of its measured strength stays in reserve, the same five-to-one design factor the rigging industry applies to lifting slings. The figure also matches the weight of the world-record seated neck lift by strongman Mike “The Machine” Bruce, for whom the MMB Pro Series is named.

“We have said for fourteen years that we build the strongest and safest neck harness in the world, and now a university laboratory has measured it,” said Thomas Hunt, co-founder of Gonza LLC. “The fabric held over half a ton. The stitching did not fail in a single test. The steel bent before anything sewn did, and on the final pull the lab’s own equipment broke before our harness. Anyone recommending a neck harness today should ask the maker one question: where is the proof it is safe under heavy load? We are the only company that can answer with an independent published study.”

Published capacity figures elsewhere in the category range from 300 to 530 pounds, according to the manufacturers’ own product listings (Gymreapers, “up to 500 lbs”; MuscleForge, “up to 530 lbs”; DMoose, “up to 300 lbs”); none is accompanied by published test data. The company notes that the NC State figures exceed the highest of those claims by roughly three times, and that Neck Flex is the only maker in the category to apply a safety factor to a measured result.

The results add to a documented record. The Neck Flex is the harness used in a 20-week randomized controlled trial by the Royal Danish Air Force, published across three peer-reviewed papers between 2015 and 2020. Gonza LLC has been granted five U.S. patents on its neck exercise device and system; in 2021 the U.S. District Court for the Western District of Texas granted the company a preliminary injunction against the maker of the Iron Neck Alpha harness, with the court’s order noting that the Alpha copied every design feature of the Neck Flex, “apparently even down to the stitching pattern,” and was made with “inferior materials” (Order Granting Preliminary Injunction, Dkt. 17, Case No. 6:21-cv-00771, Dec. 1, 2021). The Iron Neck Alpha harness was redesigned after the ruling. Athletes documented training with the Neck Flex in published reporting include UFC champion Jon Jones and boxing champion Anthony Joshua (WV News, July 2026); the Washington Business Journal has reported its appearance in Apple’s 2025 film F1 and promotion by fitness educators Jeff Nippard and Jeff Cavaliere.

“Neck training is the most valuable thing a contact-sport athlete or a bodybuilder can do, and almost nobody does it, let alone properly,” said Z.W. Elam, co-founder of Gonza LLC. “If an athlete trains neck, the equipment can’t fail, or there could be an injury. That’s why we use patented snap-resistant bands and build our harnesses for overkill. Safety is the whole point.”

The MMB Pro Series and Ballistic Kevlar^® Series kits now carry the 300-pound working-weight rating, meaning 300 pounds lifted, swung and twisted in training against a measured break strength of up to 1,461 pounds, and are available direct from Gonza LLC at https://www.theneckflex.com.

About Neck Flex^®

Neck Flex^® is the first four-way neck training harness, covering flexion, extension, lateral flexion and rotation, developed by Gonza LLC of Leesburg, Virginia, and sold since 2012. The company has been granted five U.S. patents, and its harness is named in multiple peer-reviewed studies. Kits ship complete with harness, loading chain, Bodylastics^® resistance band, door anchor and training videos.

Thomas Hunt
Gonza LLC
7034776412
support@theneckflex.com

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