Flat Iron vs Heart — What's the Difference?
Quick Answer
Side-by-side
| flat iron | heart | |
|---|---|---|
| Primal | chuck | offal |
| Muscle / location | Infraspinatus muscle, top blade of the shoulder clod | Chest cavity — between the lungs, behind the brisket |
| Character | The second most tender muscle on the entire animal, after the tenderloin. A flat, rectangular steak extracted from the top blade by splitting it along the central connective tissue. Uniform thickness makes it ideal for grilling. Also known as butler's steak in the UK. | A dense, muscular organ with a mild, beefy flavour — closer to lean muscle meat than most offal. Often grilled on skewers (anticuchos in Peru) or braised. Very lean; benefits from marination. Widely eaten in Latin America, Eastern Europe, and across Asia. |
Key differences
- Different primals: chuck vs offal.
- Texture and slicing: compare fibrous, grain-heavy cuts vs more tender steak-style muscles based on each cut’s description.
- Retail naming diverges by country—always map through a canonical cut when translating menus or labels.
When to use each
Flat Iron
Pick Flat Iron when you want its specific marbling/texture profile: The second most tender muscle on the entire animal, after the tenderloin. A flat, rectangular steak extracted from the top blade by splitting it along the central connective tissue. Uniform thickness makes it ideal for grilling. Also known as butler's steak in the UK.
Heart
Pick Heart when its primal/muscle traits fit the dish: A dense, muscular organ with a mild, beefy flavour — closer to lean muscle meat than most offal. Often grilled on skewers (anticuchos in Peru) or braised. Very lean; benefits from marination. Widely eaten in Latin America, Eastern Europe, and across Asia.
Flat Iron and Heart are different canonical muscles/primals: Flat Iron is chuck (Infraspinatus muscle, top blade of the shoulder clod); Heart is offal (Chest cavity — between the lungs, behind the brisket).
Choose based on tenderness, marbling, grain direction, and how you plan to cook (sear vs braise vs slice thin).
Read the full guides: flat iron (what-is) · heart (what-is) · flat iron hub · heart hub