A shaft that buckles on release breaks in the middle and leaves sharp edges
3 studies
The summary today
A single laboratory test, but a very clear one. Two types of aluminium kyudo shaft, compressed end-on under static and dynamic loading, give way at about 50 and 65 newtons and then snap exactly in half, with sharp metal edges, in every condition tested. It is not the material breaking from overload: stress reaches about 30 megapascals against the alloy's roughly 500, and it is column instability that bends the shaft until it snaps, after a quarter of a metre of deformation in the slow test and in about two tenths of a second in the fast one, with an almost identical pattern in both. The case the study reconstructs is a specific one: in kyudo, when the point slips behind the bow at the moment of release, the arrow is trapped between string and bow with the bow's full force, and the authors warn that the fragments fly right in front of the archer's face. That a shaft too weak for the bow can give way had already been suggested by an estimate on a compound, beyond spine 800; only this study says how and where it breaks, and only for kyudo aluminium. Carbon shafts and target arrows have not been tested.
Also phrased as: "an arrow too short snaps"; "the arrow explodes on release"; "point behind the bow at release"; "arrow breaking at full draw"; "hikikomi"
In practice
Archers are told never to use arrows shorter than their draw length and never to release with the point drawn back behind the bow, because the arrow can snap and cause injury; in kyudo the arrow is chosen longer than the draw length for this reason.
Evidence
-
2001
Context Review Published later
In the introductory part of a modelling paper, the classic column stiffness test: for every 11.1 newtons of draw weight the matching arrow undergoes 4.4 newtons of longitudinal force, and an average arrow buckles at 66 newtons and, once bent, breaks at 44. It is a reported figure, with nothing on where the shaft breaks.
Lateral deflection of archery arrows · Zanevskyy
-
2015
Context Equipment tests Published later
On a compound with a spine 500 arrow the peak axial load is estimated at about 60 newtons, against a Euler critical load of about 100: more draw weight, more point weight, a longer or weaker shaft bring the threshold closer, and with spine above 800 the author expects the arrow to fail. It is an estimate, in a preprint, and it does not describe the break.
Applications of Physics to Archery · H. O. Meyer
-
2024
For Equipment tests Published later
Two types of aluminium kyudo shaft cut to 850 mm, for bows from 98 and from 147 newtons up, compressed statically (10 mm per minute) and dynamically with a pneumatic cylinder: both buckle end-on, at about 50 and 65 newtons, and in every condition they snap exactly in half with sharp metal edges. In the static test the break comes after about 250 mm of displacement of the loading point, in the dynamic one, filmed at 800 frames per second, in about 200 milliseconds. The authors warn that, when the point slips behind the bow, the fragments fly right in front of the archer's face.
Buckling Fracture Behavior of Duralumin Arrows used for Japanese Archery · Masahiro Suetsugu, Kaori Shirakihara, Minoru Tamiaki
-
2024
For Equipment tests Published later
Under dynamic loading the peak stress in the shaft is about 30 megapascals, against the roughly 500 yield strength of 7000-series aluminium alloys: the break does not come from overloading the material but from column instability, which bends the shaft until it snaps.
Buckling Fracture Behavior of Duralumin Arrows used for Japanese Archery · Masahiro Suetsugu, Kaori Shirakihara, Minoru Tamiaki
-
2024
Context Equipment tests Published later
The dynamic test, closer to a real shot, gives a load-displacement pattern almost identical to the static one for both shafts, with the break in the middle in both cases; in the static test, after buckling, the load falls gradually while the shaft keeps bending. This is why the machine test says something about the actual release.
Buckling Fracture Behavior of Duralumin Arrows used for Japanese Archery · Masahiro Suetsugu, Kaori Shirakihara, Minoru Tamiaki
Status history
- 2001 Not studied A modelling paper reports the classic column test on arrows: an average arrow buckles at 66 newtons and, if the load continues, breaks at 44 once bent. So a shaft that has buckled is known to snap with less force than the one that bent it, but nobody has looked at where it breaks or what is left: the question is not studied.
- 2015 Not studied An estimate on a compound puts the peak axial load at about 60 newtons against a critical load of about 100, and concludes that with spine above 800 the arrow is expected to fail. It is the first indication that in target archery a shaft too weak for the bow could give way during launch, but it still says nothing on how it breaks: not studied.
- 2024 Reported The first laboratory test arrives: two types of aluminium kyudo shaft, compressed under static and dynamic loading as when the point slips behind the bow and the arrow is trapped between string and bow. In every test the shaft snaps in the middle with sharp metal edges, after about a quarter of a metre of deformation in the slow test and in about two tenths of a second in the fast one, and the stress reached is around 30 megapascals against the alloy's yield strength of about 500: what gives way is not the material but the shaft's stability. Tests on equipment count as direct evidence, but it is a single study on two shafts: reported.
Related
Related articles
- Common beginner mistakes in archery and how to avoid themThe most common beginner mistakes in archery, from posture and release to equipment, and what the measurements made on beginners actually show.
- Hands, fingers and calluses: skin, small vessels and injuries in archers who shoot a lotHarder skin, calluses, the small vessels of the fingers and acute injuries: what studies have measured in archers' hands, and how firm the findings are.
- When to retire an arrow, and why a shaft snaps on releaseWhich knocks damage an arrow, why a shaft snaps on release, and what the tests say about straightness, wear and defective arrows.
Research lines
Cite
Campagna, M. (2026). A shaft that buckles on release breaks in the middle and leaves sharp edges (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/buckled-shaft-breaks-sharp-edges
@misc{campagna2026_frecciarotturainstabilita,
author = {Campagna, Matteo},
title = {A shaft that buckles on release breaks in the middle and leaves sharp edges},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/buckled-shaft-breaks-sharp-edges},
note = {Version 1; accessed 2026-10-16}
}
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