If a Standard Punch (TL2) is sharp, it makes a distinct click as it cuts a clean hole in tubing. If the punch is dull, the hole may not cut all the way through and no click is heard.

It is easy to sharpen a Standard Punch.

Lay a piece of 180-grit sandpaper on a flat surface such a table edge. Note the bevel angle of the metal at the tip of the tool. Hold the tool at that angle to the sandpaper and slide the tool tip back and forth while at the same time rotating the tool.

Shift the tool in your hand each time so that the cutting edge is sharpened evenly all the way around.

Rotate the tool a full 360 degrees as you sweep the edge back and forth across the 180-grit sandpaper

Test the cutting edge by cutting a hole in a scrap piece of tubing. Listen for the click which indicates a sharp edge.

If you look at the sharp edge in good light, the sharper the edge the less metal you will see at the cutting edge.

Total time elapsed - about 1 minute.

Sharpen often to make cutting holes easy.