Why should using a grinder be avoided when sharpening tool heads?

Why should using a grinder be avoided when sharpening tool heads?

• A. It can temper the edge and make file sharpening difficult
• B. It dulls the blade too quickly
• C. It weakens the handle
• D. It leaves abrasive residue on tools

Answer: (A)

Grinders generate a lot of heat at the edge of the tool, which can change the metal’s hardness (temper). This tempering softens the cutting edge, reducing its ability to hold a sharp edge. Once the edge is softened, it’s harder for a file to cut cleanly and establish a precise, durable edge. That’s why grinding the edge while sharpening is avoided—the heat can ruin the edge’s hardness and undermine subsequent sharpening. To keep the edge true, sharpening with controlled filing or careful, limited grinding with rapid cooling is preferred.

Grinders generate a lot of heat at the edge of the tool, which can change the metal’s hardness (temper). This tempering softens the cutting edge, reducing its ability to hold a sharp edge. Once the edge is softened, it’s harder for a file to cut cleanly and establish a precise, durable edge. That’s why grinding the edge while sharpening is avoided—the heat can ruin the edge’s hardness and undermine subsequent sharpening. To keep the edge true, sharpening with controlled filing or careful, limited grinding with rapid cooling is preferred.