The guide offers brief introduction and popular names for the concrete anchor fasteners. The guide is very helpful to find the right anchor fastener for your project.

Concrete Double Expansion Anchor - Medium to heavy duty concrete fastener for concrete, brick and block.

Other Popular Names
double expansion anchor, double expansion shield, keystone double, double thunderloc, double, DMSA, machine screw anchor, concrete and masonry anchor.

Brief Introduction:
Double Expansion Anchors, made of a precision die-cast zinc alloy (Zamak 5), are recommended for shear loads or where the bolt is subjected to side pressure or vibration. They are made of a nut, a cone and a tubular shield that are pre-assembled into a single unit. The two-piece tubular shield contains a wedge shaped nut at one end, a wedge shaped hollow cone at the other end and is bound together with two spring bands. The placement of integral lugs on the nut and the cone keep the wedges from turning in the shied during expansion. The expansion action at both ends of the shield distributes the anchored load throughout the length of the shield.

Common variations and misspellings:
Double thunder lock, double thunderlock.

From: Concrete Fastening Systems, Inc.
More information, please visit the site http://www.confast.com
Edit by Jason