While it's difficult to determine the exact issue without more information about the specific knife you're using, it's generally not considered normal for a paring or utility knife to have trouble slicing through the skin of a mango. High-quality knives with a sharp blade should be able to cut through the mango skin with relative ease.
There are a few potential reasons why you might be experiencing difficulty:
Dull Blade: The knife blade may be dull, which can make it harder to cut through the tough skin of a mango. Over time, the blade can lose its sharpness through regular use. Consider sharpening the blade using a sharpening stone or a knife sharpener.
Incorrect Technique: It's possible that you're not using the proper cutting technique for slicing through mango skin. When cutting a mango, it's generally recommended to use a slicing motion rather than applying excessive pressure. This allows the sharp blade to glide through the skin more effectively.
Knife Design: Some knives have thicker blades or less acute angles, which can make it more challenging to cut through tough skins. However, paring and utility knives are typically designed for precise and detailed work, including peeling and slicing fruits and vegetables, so they should still be able to handle mango skin.
If you've tried sharpening the blade and using the correct cutting technique but are still experiencing difficulty, it might be worth considering a different knife or consulting a professional for further advice.