Mechanical pencil Mechanical pencil A mechanical pencil (US English) or propelling pencil (UK English), also clutch pencil, is a pencil with a replaceable and mechanically extendable solid pigment core called a "lead" . The lead, often made of graphite, is not bonded to the outer casing, and can be mechanically extended as its point is worn away. Other names include microtip pencil, automatic pencil, drafting pencil, technical pencil, click pencil, pump pen, pump pencil, leadholder, pen pencil (Indian English), and lead pencil (Bangladeshi and American English). Mechanical pencils are used to provide lines of constant width without sharpening in technical drawing and
Lead glass linking gout to lead poisoning. Items made of lead glass may leach lead into the food and beverages contained. In a study performed at North Carolina State University, the amount of lead migration was measured for port wine stored in lead crystal decanters. After two days, lead levels were 89 µg/L (micrograms per liter). After four months, lead levels were between 2,000 and 5,000 µg/L. White wine doubled its lead content within an hour of storage and tripled it within four hours. Some brandy stored in lead crystal for over five years had lead levels around 20,000 µg/L. To put