When using hold down clamps on a milling machine, what setup provides even clamping pressure?

The choice that ensures even clamping pressure when using hold down clamps on a milling machine is the setup where the T-bolt is positioned the same distance from both the workpiece and the step block, remaining parallel to the table. This alignment helps distribute the clamping force uniformly across the workpiece.

When the T-bolt is equidistant from the work and the clamp, it applies force evenly without introducing additional angles that could lead to uneven pressure or distortion of the workpiece. This uniform pressure is essential for maintaining accuracy and preventing any shifting or lifting of the workpiece during milling operations, which could impact the quality of the machined surface.

In contrast, the other setups introduce angles or unequal distances that can lead to biased pressure. For instance, an angled T-bolt can create uneven force distribution, causing the workpiece to bow or flex, while different distances from the work to the step block can similarly affect how the pressure is applied, leading to potential inaccuracies in machining.