To make an angled surface parallel to a surface plate, a machinist would use what tool?

The sine plate is the correct tool for making an angled surface parallel to a surface plate. This tool is specifically designed to hold a workpiece at a precise angle relative to a reference surface, which is usually a flat surface plate. The sine plate employs trigonometric principles to achieve accurate angles, facilitating the machining of components that need to be precisely angled for subsequent operations or for assembly.

When using a sine plate, the machinist can adjust the angle of the workpiece by using gage blocks or shim stock beneath the sine plate, effectively creating a setup that allows for accurate machining operations. This capability is particularly crucial when dealing with components that must meet strict tolerances in assemblies.

Other tools listed serve different purposes: angle blocks are used for setting up workpieces at specific angles but do not adjust the workpiece like a sine plate; height gauges are primarily for measuring vertical distances and transferring measurements, and calipers are used for measuring external and internal dimensions or depths but are not suited for creating or holding angled setups.