Why does hardware deform after CNC machining?

Deformation issues such as bending, warping, and out-of-tolerance dimensions often occur after CNC machining, directly affecting assembly and performance. Identifying the root cause and optimizing the process can effectively prevent these problems. 

1. Improper Clamping 

Excessive clamping force or uneven pressure points can cause springback once the fixture is released, especially in thin-walled or slender parts with insufficient rigidity. This is particularly noticeable in soft materials like aluminum and copper. Optimization: Use custom fixtures to distribute pressure; employ vacuum suction for thin-walled parts, and ensure moderate clamping force. 

2. Cutting Heat & Cutting Force

Friction during cutting generates significant heat, leading to thermal expansion and internal stress. Additionally, improper parameters or excessive cutting force can physically bend the workpiece. Optimization: Use high speeds, shallow cutting depths, and appropriate feed rates; increase coolant flow; use layered or symmetrical cutting for large parts to balance stress. 

3. Release of Internal Material Stress 

Castings, forgings, and heat-treated steels have inherent internal stresses. Removing material breaks this balance, causing the part to deform as the stress releases over time. Optimization: Perform annealing or aging treatments before machining; allow the part to 'rest' after rough machining to release pressure before finishing.