Superabrasives like synthetic diamonds are indispensable in today’s construction industry, particularly for core drilling applications in reinforced concrete. The increase of the cutting efficiency of such core bits strongly depends on the material removal behavior of single diamond grains placed in a diamond segment acting as cutting elements. Therefore, this paper presents a newly developed experimental setup for a 3-mm single diamond grain scratch test, as well as the application of a Smoothed Particle Hydrodynamics (SPH) method to model single diamond grains scratching a rebar base material at operational parameters. Diamonds in two main different crystallographic and geometric orientations are tested and investigated with respect to their forces and temperatures at the cutting edge. Furthermore, the chip formation and different material removal mechanisms are analyzed for each orientation and compared with the model output. Validation tests and sensitivity analyses are performed in 3D and high resolution, thanks to the runtime acceleration of SPH through parallel computing on the graphics card. The results indicate: 1) A significantly different material removal behavior as a result of changing the diamond orientation; 2) The capability and high efficiency of SPH for modeling single grain scratch tests.