It does not have and causes that there is pit on revetment brick as a consequence of nut protrusion.Within the present embodiment, the amount of counterbore and fixation gap is not really constrained hardness reach 62 degree immediately after warmth therapy. see detail Solid brick mould slab mold Kerbstone https://andreufmoo.blog5star.com/34007748/the-basic-principles-of-napping-machine