A rugged fusion of military heritage and premium Japanese denim, the IHSH-427 is Iron Heart’s heavyweight take on the classic CPO overshirt—engineered for durability, structure, and long-term wear.
Constructed from 16oz Japanese selvedge denim, this shirt delivers a dense, textured hand with the brand’s signature toughness. The black sulphur-dyed finish will gradually fade with wear, revealing high-contrast character and unique patina over time. Woven using ring-spun cotton yarns, the fabric develops vertical fading (“tate-ochi”) similar to vintage denim, making each piece distinctly personal with age.
Cut in a traditional CPO silhouette, the IHSH-427 features a slightly longer body and a roomier fit than standard Iron Heart shirts—ideal for layering as a lightweight jacket. Functional details include oversized chest pockets, side handwarmer pockets, and heavy-duty snap fastenings for ease of wear.
Features
Size L
16oz Japanese selvedge denim
Sulphur/overdyed black – designed to fade with wear
CPO-style overshirt construction (longer length)
Heavy-duty snap front closure
Dual chest pockets + handwarmer pockets
Straight back yoke (non-western styling)
Corduroy-lined collar (on most variants)
Chainstitched and felled seam construction
One-washed (minimal shrinkage expected)
Made in Japan
Fit Notes
Relaxed/overshirt fit compared to Iron Heart western/work shirts
Typically runs slightly small; many size up for layering
Size L works well as a mid-layer or light outerwear piece
A rugged fusion of military heritage and premium Japanese denim, the IHSH-427 is Iron Heart’s heavyweight take on the classic CPO overshirt—engineered for durability, structure, and long-term wear.
Constructed from 16oz Japanese selvedge denim, this shirt delivers a dense, textured hand with the brand’s signature toughness. The black sulphur-dyed finish will gradually fade with wear, revealing high-contrast character and unique patina over time. Woven using ring-spun cotton yarns, the fabric develops vertical fading (“tate-ochi”) similar to vintage denim, making each piece distinctly personal with age.
Cut in a traditional CPO silhouette, the IHSH-427 features a slightly longer body and a roomier fit than standard Iron Heart shirts—ideal for layering as a lightweight jacket. Functional details include oversized chest pockets, side handwarmer pockets, and heavy-duty snap fastenings for ease of wear.
Features
Size L
16oz Japanese selvedge denim
Sulphur/overdyed black – designed to fade with wear
CPO-style overshirt construction (longer length)
Heavy-duty snap front closure
Dual chest pockets + handwarmer pockets
Straight back yoke (non-western styling)
Corduroy-lined collar (on most variants)
Chainstitched and felled seam construction
One-washed (minimal shrinkage expected)
Made in Japan
Fit Notes
Relaxed/overshirt fit compared to Iron Heart western/work shirts
Typically runs slightly small; many size up for layering
Size L works well as a mid-layer or light outerwear piece
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