It is generally accepted the harder grinding balls are better grinding balls. This is true in most cases, as a rule. However, sometimes there are situations when it’s necessary to use softer grinding balls for the material grinding (for example, grinding balls with surface hardness 48-50HRC). This depends on the material grinding hardness, the armor condition and armor quality, in most cases.
It is worth paying attention to one nuance: the existing regulatory documents for grinding balls (GOST 7524-2015 and DSTU 8538-2015) during ordering and buying such grinding balls. These documents regulate only the lower limit hardness range for each hardness group, i.e. grinding balls should have hardness not less than a certain value (this value is own for each hardness group). Here you can see the current standards for steel grinding balls. The hardness range upper limit is not controlled. Therefore, during buying grinding balls with the second hardness group or with surface hardness at least 49HRC, you can get the grinding balls with surface hardness higher than that expected (for example, 65HRC). You will not be able to raise a claim to supplier after receiving such grinding balls because manufacturer didn’t violate the requirements of DSTU and GOST in fact. The grinding balls have hardness indeed no less than 49HRC, as noted in the regulatory document. However, such grinding balls using can adversely affect at your production for the grinding process and lead to grinding media splitting, increased consumption, the technological equipment deterioration and armor plates wear increased. Therefore, during buying the grinding balls with lower hardness groups, if this is really a principal for you, pay your attention and ask the manufacturer additionally for the upper hardness limit, to make sure that you’ll not get harder grinding balls instead the soft ones.
ENERGOSTEEL Company always fully satisfies our customer’s requirements for the grinding media quality, basis on the individual characteristics of grinding technology at each particular enterprise. We can produce grinding media with different hardness that is necessary for the client. Thanks to the modern hardening metal methods used in our production, we can produce the steel grinding balls with hardness corresponds to a certain group and with maximum hardness limit clearly specified with the final client.