As correctly pointed out by ASimpson, there are classification of fits which are application specific. He lists the metric version, imperial are equivalents noting 1.0 inch = 25.4 mm. There are several good references on this, look to the web. But the Machinist Handbook does discuss this, at least in the 23rd edition.
How does Dhea work? DHEA is a parent hormone produced by the adrenal glands near the kidneys and in the liver. In men, DHEA is also secreted by the testes. It is changed in the body to a hormone called androstenedione. Androstenedione is then changed into the major male and female hormones.
DHEA is a hormone that your body makes naturally. Itâs available as a supplement and is a common ingredient in testosterone boosters. There is some evidence that DHEA supplementation can increase levels of free testosterone in men, but itâs limited. DHEA also comes with safety concerns. Side effects include hair loss, upset stomach, and high blood pressure.