Maximum diameter of the clearance hole for a M20 anchor

The principle here is that the gap should not be too large. it depends on on the product used. A larger gap can lead to increased shrinkage, potentially causing cracks. The Hilti HIT-RE500-V3/HIT-HY 200-A/R injection mortar has only been thoroughly tested for use in standard anchoring applications, where the annular gap i.e. difference between clearance hole on the baseplate and threaded rod diameter, is in the range of 2-3 mm.