Naval engineer Richard James inadvertently invented the stair-descending spring during a failed attempt at making stabilizers for ships' instruments during World War II. After he sold a bunch to a department store in Philadelphia in 1945, demand became so great that James started mass-producing them there. Production eventually moved to Hollidayville, Pa., where more than 300 million have been made to date. It's still fairly cheap, too, with the average Slinky selling for roughly $5.
Check Out Our Best Services for Investors
- $2.5+ million portfolio
- Large-cap and dividend focus
- Intraday trade alerts from Cramer
Access the tool that DOMINATES the Russell 2000 and the S&P 500.
- Buy, hold, or sell recommendations for over 4,300 stocks
- Unlimited research reports on your favorite stocks
- A custom stock screener
- Model portfolio
- Stocks trading below $10
- Intraday trade alerts