A cornerstone of Japanese denim craftsmanship, the Iron Heart 634S represents the brand’s original straight-cut silhouette, constructed from their legendary 21oz selvedge denim. Designed by Shinichi Haraki and produced in Japan, this model is revered for its durability, structure, and exceptional aging potential.
This pair features a deep indigo rope-dyed warp with a natural weft, woven in a right-hand twill using a low-tension technique. The result is a heavyweight denim that starts rigid but gradually softens and molds to the wearer, developing high-contrast fades unique to each owner.
The 634 cut offers a timeless straight leg with a medium rise, providing a balanced fit that works equally well with boots or sneakers. Classic Iron Heart construction details include a button fly, hidden rivets, reinforced belt loops, and chain-stitched seams throughout.
Finished with a selvedge ID visible at the outseam (as shown in cuffed photos), this pair embodies everything expected from premium Japanese raw denim.
Key Features:
21oz Japanese selvedge denim (signature Iron Heart fabric)
Straight cut (IH-634S) – medium rise, classic leg
Indigo rope-dyed warp / white weft
Button fly construction
Hidden rivets and reinforced stitching
Selvedge ID at side seam (visible when cuffed)
Made in Japan
Sanforized & one-washed (minimal shrinkage)
A cornerstone of Japanese denim craftsmanship, the Iron Heart 634S represents the brand’s original straight-cut silhouette, constructed from their legendary 21oz selvedge denim. Designed by Shinichi Haraki and produced in Japan, this model is revered for its durability, structure, and exceptional aging potential.
This pair features a deep indigo rope-dyed warp with a natural weft, woven in a right-hand twill using a low-tension technique. The result is a heavyweight denim that starts rigid but gradually softens and molds to the wearer, developing high-contrast fades unique to each owner.
The 634 cut offers a timeless straight leg with a medium rise, providing a balanced fit that works equally well with boots or sneakers. Classic Iron Heart construction details include a button fly, hidden rivets, reinforced belt loops, and chain-stitched seams throughout.
Finished with a selvedge ID visible at the outseam (as shown in cuffed photos), this pair embodies everything expected from premium Japanese raw denim.
Key Features:
21oz Japanese selvedge denim (signature Iron Heart fabric)
Straight cut (IH-634S) – medium rise, classic leg
Indigo rope-dyed warp / white weft
Button fly construction
Hidden rivets and reinforced stitching
Selvedge ID at side seam (visible when cuffed)
Made in Japan
Sanforized & one-washed (minimal shrinkage)
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