Secure grinder blade and tapered tool—side locking hub for flush cutting concrete

A system comprising:

• a grinder;
• a grinder blade with a core material comprising a hard metal or a hard metal alloy for flush cutting concrete, the grinder blade further comprising:
• a top side configured to face the grinder to which the grinder blade is configured to attach;
• an outer edge operable to enable the grinder blade to make a perpendicular cut into a surface of a first section of concrete up to a radial depth of the grinder blade that is proximate to a locking hub receiver section on the top side of the grinder blade, wherein the perpendicular cut is perpendicular relative to the surface of the first section of concrete;
• a bottom side opposite of the top side, and configured to make flush contact with a section of concrete that is perpendicularly adjoined to the first section of concrete concurrently with the outer edge perpendicularly cutting into the first section of concrete;
• and
• the locking hub receiver section being unitarily formed from the grinder blade at a center portion and angled toward the grinder to which the grinder blade attaches to receive a locking hub and comprising a plurality of holes configured to allow a plurality of fasteners to be inserted from the top side of the grinder blade and tightened by heads of a plurality of threaded fasteners from the top side of the grinder blade to secure the locking hub against the grinder blade:
• the locking hub comprising:
• a solid geometric form that substantially conforms to the locking hub receiver section and comprises one or more angled top side portions extending between a top planar surface of the solid geometric form and a top intersection with a corresponding base;
• a spindle engaging bore extending perpendicularly into the top planar surface of the locking hub configured to engage with a spindle of the grinder to which the grinder blade is configured to attach;
• and
• two or more threaded fastener engaging bores extending into tapered side portions of the locking hub that are configured to be tightened against the locking hub receiver section of the grinder blade by tightening heads of the plurality of threaded fasteners from the top side of the grinder blade.