I was told by a experienced guy about the tool - using this tool with teeth blades - It can catch and can kick out of your hands fly in the air and cut your shoulder OFF (nice). With the fiber type i felt no kick issue BUT I am going to be on guard . What I see is the main technique - first make the diagonal hole slowly .Then work the tool up slow . This tool you need not rush . don't force it . Same as a angle grinder but some times we might impatiently force a small one - this tool NO .