What causes warping when grinding long slender pieces?

Warping in long slender pieces during grinding primarily results from heat build-up, which can cause heat checking. When a hard grinding wheel operates, it can generate significant friction and temperature at the contact point with the workpiece. This localized heat can lead to uneven thermal expansion across the length of the slender piece, causing it to warp as different areas of the material expand and contract.

Using a hard wheel can exacerbate this situation, particularly if the grinding conditions are not optimized. The rigorous grinding action with a hard wheel can introduce surface stresses and lead to micro-cracks, known as heat checks, both of which can distort the geometry of the workpiece. To mitigate warping, it's essential to manage the grinding parameters, such as checking the hardness of the wheel and ensuring appropriate cooling and feed rates, to avoid excessive heat generation.