Pattern Steel Guide — Fish Skin, Copper Coin, Damascus & More

Introduction

Pattern steel is the pinnacle of visual craftsmanship in sword-making — blades where the grain pattern itself is a deliberate work of art. From the subtle fish skin clusters of traditional Japanese swords to the dramatic flowing patterns of Damascus, pattern steel represents the highest level of aesthetic achievement in blade-making.

This guide covers all the major pattern steel types — how they're made, what they look like, and which is right for your collection. Browse our Damascus katana collection and folded steel collection to see pattern steel in action.

The History of Pattern Steel

Pattern steel has been produced independently in multiple cultures throughout history. In Japan, the folding process created the hada (grain pattern) as a byproduct of steel refinement. In the Middle East and South Asia, the wootz crucible steel process created the distinctive wavy patterns of historical Damascus steel. In China, traditional swordsmiths developed their own pattern steel traditions — including the fish skin (samegawa) and copper coin (tongqian wen) patterns that are among the rarest and most prized in the world.

Today, pattern steel is produced worldwide using both traditional and modern techniques — from the traditional tatara-smelted Yu steel of Chinese master swordsmiths to the modern pattern-welded Damascus of contemporary bladesmiths.

Fish Skin Pattern (Samegawa Hada, 髨皮肇)

The fish skin pattern is one of the most distinctive and sought-after grain patterns in Japanese and Chinese sword-making. Named for its resemblance to the skin of a shark or ray (samegawa — the same material used to wrap katana handles), the fish skin pattern is created through a specific folding and forge-welding technique that produces small, rounded grain clusters resembling fish scales.

The fish skin pattern is extraordinarily difficult to achieve consistently and is considered a mark of the highest level of swordsmith skill. Each fish skin pattern blade is unique — the pattern cannot be replicated exactly. The fish skin pattern is most visible in raking light, where the rounded clusters catch the light differently from the surrounding steel.

Copper Coin Pattern (Tongqian Wen, 铜錢纹)

The copper coin pattern is one of the rarest grain patterns in Chinese sword-making — circular or oval grain clusters that resemble traditional Chinese copper coins. The copper coin pattern is created through a specific folding technique that produces circular grain formations rather than the elongated formations of most other patterns.

Like the fish skin pattern, the copper coin pattern is extremely difficult to achieve and is considered a mark of exceptional swordsmith skill. A blade with a genuine copper coin pattern is a collector's piece of the highest order.

Damascus Patterns

Ladder Pattern: Created by grinding parallel grooves into the Damascus billet before drawing out — producing a pattern of parallel lines with connecting rungs. Dramatic and geometric.

Twist Pattern: Created by twisting the Damascus billet before drawing out — producing a flowing, rope-like pattern that spirals along the blade. One of the most popular Damascus patterns.

Rose Pattern: A complex manipulation that produces circular, rose-like formations. One of the most difficult and prized Damascus patterns.

Raindrop Pattern: Created by drilling or grinding dimples into the billet — producing circular "raindrop" formations. Striking and distinctive.

Browse our Damascus katana collection for examples of these patterns.

Pattern Steel vs Folded Steel — What's the Difference?

Folded steel is a single type of steel that has been folded to refine it and create a subtle grain pattern (hada). The pattern is visible but not dramatically contrasting.

Pattern steel (including Damascus) is created by forge-welding two or more different types of steel together, creating a high-contrast visual pattern. The visual effect is much more dramatic than folded steel.

Both are legitimate traditional techniques — they simply produce different visual results. Browse our folded steel collection for comparison.

FAQ

Q: What is the rarest pattern steel?
The fish skin (samegawa hada) and copper coin (tongqian wen) patterns are among the rarest — requiring extraordinary swordsmith skill to achieve consistently.

Q: Is pattern steel stronger than regular steel?
Pattern steel performance depends on the steels used and heat treatment quality — not the pattern itself. A well-made pattern steel blade can match a mono-steel blade in performance.

Q: How do I maintain a pattern steel blade?
Pattern steel requires careful maintenance — wipe after every handling, oil regularly, avoid harsh chemicals. See our sword care guide.

Q: Will the Damascus pattern fade?
Over time, the etched pattern may fade. It can be re-revealed by light re-etching with ferric chloride — consult a professional.

Q: What is the difference between Damascus and folded steel?
Folded steel is a single steel type folded to create a subtle hada. Damascus is two or more steels forge-welded together to create a high-contrast pattern.

Summary

Pattern steel represents the pinnacle of visual craftsmanship in sword-making — from the subtle fish skin clusters of traditional Japanese and Chinese swords to the dramatic flowing patterns of Damascus. Each pattern type requires specific techniques and extraordinary skill to achieve, making pattern steel blades among the most prized collector pieces available.

Shop Pattern Steel Katana

• Damascus Katana Collection — dramatic flowing patterns
• Folded Steel Katana Collection — traditional hada patterns
• Handmade Katana Collection — all handcrafted blades
• Damascus Steel Guide
• Folded Steel Guide