Minecraft wiki entry for Iron_Golem, associated text: Iron golems have different stages of being cracked to show their health. When their health is above 74 × 37, they do not have any cracks. When their health is between 50 × 25 and 74 × 37, some cracks appear. When their health is between 25 × 12.5 and 49 × 24.5, they appear more cracked. When their health is lower than 25 × 12.5, many cracks are visible.