The head center of the soldering iron head is provided with a centering pin positioned at the center point of the circular ring circle and rising a little altitude than the circular ring plane.

在所述烙铁头的头部中心有一定心针，该定心针位于圆环的圆心处，高度略微高出圆环平面。

youdao

It is a Latin word that means "ring" or "circle."

VOA: special.2009.01.11

The Ring is a circle of beech trees, planted on a hilltop that had been the site of Bronze Age and Iron Age fortifications, and a Roman temple.

BBC: England��s ghostly South Downs Way

The outer ring and the inner circle are made from different alloys, which have different electric potentials.

ECONOMIST: Why the euro may be a rash move

Twice puff-adders came twisting into the alert ring of our debating coffee-circle.

NEWYORKER: How David Beats Goliath