8 Units of Measure
A unit of measure is a standardised quantity of a physical property, e.g., length or weight. Metric units are the most common units. Imperial units are still used for some purposes in the United Kingdom and some other countries. Both are used in P&O.
1/4″ = quarter inch
For example, measurement of length for typical plastics include the following:
| Drape molding | Plastic type | |
| 1/16″ | tongues | LDPE/HDPE |
| 1/8″ | kids | PP |
| 5/32″ | small adults | PP |
| 3/16″ | standard adults | PP |
| 1/4″ | increased weight/activity | PP |
| Bubble forming | ||
| 3/8″ | narrow/short sockets (like arms) | PETG (Vivac) |
| 1/2″ | medium/long sockets | PETG |
| 1/2″ | Flexible inner sockets | EVA |