The propelling pencil
is a mechanical writing instrument with a thin, cylindrical lead sleeve. This pencil is used by professional artists for drafting and sketching. They also have a slim design that is comfortable to hold.
A mechanical pencil uses a complicated mechanism that has been tested for years. It is a very efficient device and works well. But, it can be confusing to use.
Most pencils have a push button on top or side of the pencil. Pressing this button is usually necessary to advance the lead. Other pencils have a ratchet mechanism that moves the lead in fixed increments. However, there are many different activation methods.
Another mechanical pencil has a clicky mechanism that advances the lead by a smooth motion. Some users prefer this style. Others prefer to click the lead out the old-fashioned way.
Unlike a ratchet mechanism, a clicky pencil does not require any special attention. Instead, the lead advances smoothly and does not catch the paper.
If the lead is too loose, it can be bent into a slight oval shape. If the lead is too tight, it can be shaved as it is inserted.
Some pencils have a double-knock mechanism. When you press the tip against something, the spring-loaded collar extends. This allows for a quick retracting.
Some pencils have a twisting mechanism. This allows the user to advance the lead in small increments. These pencils usually have a top or side button that allows the user to press the lead manually.