Can using a checkering file cause the blade to crack?

[P.K.Hansen]

I'm planning a campknife on which I want to use my checkeringfile to make grooves for a firesteel.
I want to harden that part of the blade, but will the grooves cause stressrisers, which can make the blade snap when quenching? They'll be on the back.
So far I've only used the file on clayhardened blades after heattreating was done.

 

[A C Richards]

In theory, Yes it can create stress risers. But that does not mean it WILL crack. It might crack and your chances are much greater with the file grooves. If you need them to be hardened I would just barely mark the blade with the checkering file to set your spacing, then use a diamond file to finish them after heat treat.