What the bowyer says about the core materials of the Japanese bow only partly holds up in mechanical testing
1 study
The summary today
There is a single comparison, in a 2017 review of the materials of the Kyoto bow, between the vocabulary of a master bowyer and a laboratory test on the core materials. The specimens, 5 millimetres thick and loaded in three-point bending over an 80 millimetre span, bear the bowyer out on two materials out of three: hazenoki rises linearly until it breaks with minimal strain, so it does behave as a brittle wood, and maple reaches larger strain at failure, as befits the wood he calls tough. The third does not fit: higo, which the bowyer describes as hard and brittle like hazenoki, instead reaches larger strain at failure, as maple does. The comparison is more interesting for its method than for its result, because the bowyer's words are not measurable quantities and there is a single test, with one curve per material and no stated repeats.
Also phrased as: "yumi core materials"; "nakauchi"; "hazenoki in the Japanese bow"; "craft knowledge and mechanical testing"; "bows from Kyoto workshops"
In practice
Japanese bowyers describe the core materials with words handed down over generations, hard, brittle, tough, and use those words to decide how to put the bow together.
Evidence
-
2017
For Equipment tests Published later
Three-point bending on the core materials of the Kyoto bow (higo, hazenoki, maple), 5 millimetres thick, 80 millimetre span (ratio 16), rate 50 millimetres per minute: hazenoki rises linearly to failure with small strain, while higo and maple reach larger strain at failure. The result matches hazenoki hard and brittle, maple tough, but not higo hard and brittle.
Materials Technology in Kyoto Bow · Hiroyuki Hamada
Status history
- 2017 Reported A review of the materials of the Kyoto bow puts a master bowyer's vocabulary to the test with three-point bending on the core materials: 5 millimetre specimens, an 80 millimetre span, a rate of 50 millimetres per minute. Hazenoki behaves as a brittle wood, as the bowyer says, and maple as a tough one; higo, which he calls hard and brittle, instead reaches larger strain at failure. It is a test on equipment, so direct for this claim, but it is a single test, with one curve per material, and it compares words with curves: reported.
Related
Related articles
- The yumi through engineering: materials, asymmetric limbs, draw force and tenouchiHow the Japanese bow works according to the measurements: bamboo and core woods, animal glue, asymmetric limbs, the draw force curve and tenouchi twist.
- What a bow is made of: what the materials of limbs, riser, string and arrows changeWood, horn, carbon, glass fibre: what bench tests on limbs, risers, strings and arrows have measured, and how much of it reaches the archer's hand.
Research lines
Cite
Campagna, M. (2026). What the bowyer says about the core materials of the Japanese bow only partly holds up in mechanical testing (Version 1). In Evidence Registry. Retrieved 16 October 2026, from https://matteocampagna.com/en/registry/equipment/japanese-bow-core-materials-bowyer
@misc{campagna2026_yumilegniartigiano,
author = {Campagna, Matteo},
title = {What the bowyer says about the core materials of the Japanese bow only partly holds up in mechanical testing},
year = {2026},
howpublished = {Evidence Registry, matteocampagna.com},
url = {https://matteocampagna.com/en/registry/equipment/japanese-bow-core-materials-bowyer},
note = {Version 1; accessed 2026-10-16}
}
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