Sharpeners.

Thick coloured and art pencils are usually 11 mm. A double sharpener covers both common sizes with 8 and 11 mm. For jumbo coloured pencils from 12 mm up there are dedicated models, some with twin-blade technology for a round, break-resistant point.

Our range for thick pencils covers 9, 12, 16 and 17 mm — for example the Big 12 for 12 mm or the 100-70 for pencils up to 17 mm. These models are built for jumbo pencils and wax crayons.

A lead sharpener doesn't sharpen the whole pencil, just the bare lead of a mechanical pencil. Our models are tuned for 2 mm and 3.15 mm and guide the lead through a controlled cut.

The usual causes are a loose or blunt blade, too much pressure while sharpening, a lead that was already damaged, or the wrong diameter. Turn slowly and with a light touch, check the blade and choose the right diameter.

Our blade is curved. That shape keeps the cutting edges under constant tension, so they aren't lifted by the pencil while sharpening. That stops the point from springing back and tearing. It also keeps pressure on the blade screw, so it doesn't loosen as easily.

Because pencil leads contain clay, a mineral component. Normally metal grinds stone; sharpening does the reverse. For comparison, high-quality kitchen knives reach at most around 53 HRC.

A standard pencil measures 8 mm, thicker colouring pencils usually 11 mm. That's why double sharpeners typically have exactly those two holes.

A container catches the shavings and is useful anywhere there's no bin within reach. Models without a container are more compact and durable, since they have no mechanism that can break.

No. It's too easy to change the correct cutting angle doing that. If the point tears or the wood frays, fit a replacement blade instead — but first check whether the blade is simply loose or dirty.

In Erlangen. We have our own production there, a development department and a tool- and machine-building department — at the same site since the company was founded in 1919.