let me explain why the hardness of the products within one shipping lot is different:
first of all, we produce according to your drawings, the hardness range of the material is hb150-230, and we do not pay attention to whether the hardness of the products within one shipping lot is different;
secondly, the blanks of products within one shipping lot for you, are finished in several times. sometimes, when casting the blanks, other customers' products will be put together, thus lead to the differences of hardness.
in future shipments, we will pay attention to this issue and avoid similar problems from happening again.