Hi @kymmccarthy11,
Thank you for your post about cutting through security mesh.
I'd be surprised if the disc you are using is the problem. As long as they are a thin cut-off blade, there is not too much difference in the quality. Is it possible to get some photos of the grinding discs that you have?
I'd suggest the issue is more likely with the tool or the battery.
What size battery have you got in your angle grinder and is it fully charged? Is it a new battery? Does the grinder run consistently when there is no load applied to it?
You might have some trouble with the power output if you are using a low Ah (amp hour) battery. Unless they are fully charged and relatively new, the lower Ah batteries sometimes struggle to output enough power to overcome the higher torque load applied to the motor when grinding.
If you haven't got a higher Ah battery, I would take the grinder with you back to your local store and head to the Tool Shop. They will have some store-use batteries there that you can use to test the tool.
If you have an issue with the store use batteries, there is possibly a problem with the tool that would entitle you to a replacement. If you have no issues using their batteries, I would suggest you pick up a higher Ah battery such as this RYOBI 18V ONE+ 4.0Ah Lithium Battery.
Let me know what you think and if you have any further questions.
Jacob
