Unshakable in Chinese / Japanese...

金剛不壞 is originally a Buddhist term for “The diamond indestructible.”

Sometimes, it's written 金剛不壞身, The diamond-indestructible body.

Outside that context, it still means firm and solid, sturdy and indestructible, unshakable, or adamantine (a mythological indestructible material).

Note: If you order this from the Japanese master calligrapher, the last Kanji will look like the one shown to the right.

不動心 is one of the five spirits of the warrior (budo) and is often used as a Japanese martial arts tenet.

Under that context, places such as the Budo Dojo define it this way: An unshakable mind and an immovable spirit is the state of fudoshin. It is courage and stability displayed both mentally and physically. Rather than indicating rigidity and inflexibility, fudoshin describes a condition that is not easily upset by internal thoughts or external forces. It is capable of receiving a strong attack while retaining composure and balance. It receives and yields lightly, grounds to the earth, and reflects aggression back to the source.

Other translations of this title include imperturbability, steadfastness, keeping a cool head in an emergency, or keeping one's calm (during a fight).

The first two Kanji alone mean immobility, firmness, fixed, steadfastness, motionless, and idle.

The last Kanji means heart, mind, soul, or essence.

Together, these three Kanji create a title defined as “immovable mind” within the context of Japanese martial arts. However, in Chinese, it would mean “motionless heart,” and in Korean Hanja, “wafting heart” or “floating heart.”

堅忍不抜 means determined, steadfast, unswerving, or unshakable in Japanese.

This is the Japanese version of an old Chinese 4-character perseverance proverb.
This would be understood in Chinese, but it's not commonly written this way in Chinese.

Note that when writing this as Kanji, Japanese calligraphers sometimes write the second Kanji in the form shown to the right. Yes, it’s just one stroke that is slightly different in location, crossing another stroke in this alternate Japanese Kanji form. If you have a preference, let us know when you order.

Due to some odd computer coding conventions, these two character forms were combined/merged into the same code point - thus, you will not see Kanji images of more Japanese form as you select options for your scroll.

鐵了心 is a Chinese title that means determined or unshakable.

This literally means “Iron Heart” or “Heart of Iron.”