Purchase Concrete Double Expansion Anchors
Technical Information:
The Double expansion anchor consists of a cone nut, a hollow cone and a tubular shield preassembled into a single unit. The two piece tubular shield is bound together with a spring band. It contains a wedge shaped nut at one end and a wedge shaped hollow cone at the other end. Integral lugs on the cone nut and the hollow cone keep the wedges from turning in the tubular shield during expansion. The anchors are made of a precision die-cast zinc alloy commonly known as Zamak. The expansion action at both ends of the anchor distributes the anchored load throughout the length of the anchor. This expansion anchor is recommended for shear loads or where the bolt is subjected to side pressure or vibration. Once fastened, the object may be unbolted, removed, and/or re-fastened without affecting the holding values of the anchor.
Double Expansion Anchor concrete anchor/fastener -
Approvals:
Meets GSA Specification FF-S-325, Group II, Type 2, Class 2, Style 2
Double Expansion Anchor concrete anchor/fastener -
Applications:
Light to Medium-duty in concrete, brick and block.
Double Expansion Anchor concrete anchor/fastener -
Installation:
- Using a hammer drill and a carbide tipped masonry bit, drill a hole of recommended diameter (see chart below) into the base material to a depth equal to, or slightly deeper than, the length of the expansion shield.
- Clear the hole of all debris.
- Place the Double Expansion anchor, nut end first, into the hole. The top end of the anchor should be flush or slightly below the base material surface.
- Place the object to be fastened over the anchor in the base material and bolt in to place. The bolt should sufficiently engage the threads of the anchor.
Double Expansion Anchor concrete anchor/fastener -
Bolt
Length:
The length of the machine bolt required is equal to the thickness of the material to be fastened plus the length of the double expansion anchor.
Double Expansion Anchor concrete anchor/fastener -
Anchor
Spacing:
The forces on a Double expansion anchor are transferred
to the base material in which it is installed. If the anchors are
installed too close together, it can cause an interaction
of the forces, thus reducing the holding power of the anchors.
As a rule of thumb, the expansion industry has established
a minimum standard of ten (10) anchor diameters for spacing
between anchors and five (5) anchor diameters from an unsupported
edge. When vibration or sudden impact are part of the load
condition anchor spacing should be increased.
Double Expansion Anchor concrete anchor/fastener -
Technical
Data
| |
3000 psi concrete |
| Anchor Size |
Anchor Length |
Hole Size |
Bolt Dia. |
Pull-Out |
| 1/4" |
1-5/16" |
1/2" |
1/4" |
2332 lb. |
| 5/16" |
1-5/8" |
5/8" |
5/16" |
2948 lb. |
| 3/8" |
2" |
3/4" |
3/8" |
4972 lb. |
| 1/2" |
2-5/16" |
7/8" |
1/2" |
9042 lb. |
| 5/8" |
2-5/8" |
1" |
5/8" |
13,574 lb. |
| 3/4" |
3-15/16" |
1-1/4" |
3/4" |
16,962 lb. |
Values shown are average ultimate values and are offered only
as a guide and are not guaranteed. A safety factor of 4:1 or
25% is generally accepted as a safe working load. Reference
should be made to applicable codes for the specific working
ratio.