KUM Standard Replacement Blades (3 pcs.)

The KUM replacement blade Standard is a replacement knife for KUM sharpeners with standard opening – designed for the moment when the blade has become dull and the sharpener itself still works perfectly. Made from finely ground hard carbon steel, hardened to over 62 HRC and thus significantly harder than ordinary steel tools. Manufactured in Germany.

Features

• Hard carbon steel, 62+ HRC: The blade is so hard that it cuts cleanly and without tearing even with soft graphite leads – the wood of the pencil is smoothly removed, the lead maintains its shape.
• Finely ground: The grind is tailored to sharpening pencils and colored pencils – razor-sharp at the edge, without breaking the lead when applied.
• Dynamic Torsion Action: The knife is slightly curved and under constant tension – so the cutting edge stays in constant contact with the pencil and produces an even, conical point without readjustment.
• Screw fastening: The blade is fixed with a screw, not riveted or clamped – replacement with a small screwdriver, without special tools.
• Right-hand design: The blade geometry is designed for right-hand sharpeners of the KUM standard series (e.g. 530S).
• Manufactured in Germany: Production in Erlangen, Bavaria.

Application & Tips

• When to replace? If the sharpener noticeably increases resistance when turning, the wood frays instead of being removed cleanly, or the lead repeatedly breaks – then the blade is dull, not the pencil too soft.
• Replacement: Loosen the mounting screw, remove the blade, insert the new blade, tighten the screw by hand. The blade is ready to use immediately after tightening.
• Pencils and colored pencils: The standard blade is suitable for regular pencils and medium-hard colored pencils. For very soft, oil-based colored pencil leads (e.g. watercolor pencils), a brief wiping of the blade after sharpening is recommended so that color abrasion does not accumulate.
• For artists and sketching work: A fresh blade makes a difference when a fine, stable point is needed for hatching or details – a sharp blade breaks the lead less easily than a dull one, which pushes instead of cuts.
• Durability: A well-maintained blade – occasionally wiped dry – lasts considerably longer than one that becomes clogged with wood dust and graphite abrasion.

For Sharpener Enthusiasts

KUM uses a characteristically curved knife in its standard sharpeners, which generates consistent cutting pressure even with different pencil diameters through its pre-tension (Dynamic Torsion Action). The steel is over 62 HRC – for comparison: professional kitchen knives are around 55–60 HRC. Before delivery, the blades are polished, ultrasonically cleaned and conserved with oil, which protects the carbon steel from corrosion. Those who work with graphite pencils of various hardness grades will notice that a fresh blade requires noticeably less pressure when sharpening hard grades (e.g. 3H–5H).

Technical Data