Grinder not best tool to cut concrete?
You have the retaining nut on wrong--flat side down --
Also, Get a diamond dry cutting blade--They should be around $10-- and will last a long,long time--
The abrasive cut off wheels cost more in the long run because they wear out so quickly.
Harbor freight has a three pack of diamond blade for about $20 I only need about 3 a year and they do a lot of work in that year.---Mike---
New members: Adding your location to your profile helps in many ways.--M--