There are numerous technical specifications that must be considered when using Lag Shield Anchors, including diameter, internal thread length, minimum embedment and required hole size. The Lag Shield Anchor is a great fastener when very hard (short) concrete or lower grade (long) concrete is a concern. The size of the anchor refers to the diameter of the lag bolt to be used with this fastener. Once all these factors have been determined, you can find the expected holding values in the technical information below.
To determine the length required, add the thickness of the material to be fastened, plus the lag shield anchor length, plus an additional half an inch. NOTE: The tip of the screw must protrude from the bottom of the lag shield anchor to ensure proper expansion.
The forces on a Lag Shield Anchor are transferred to the 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. As a rule of thumb, the expansion anchor 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 conditions, the spacing should be increased.
Technical Information: Ultimate Load Values in 2000 PSI Concrete
|Size||Minimum Embedment||Max. Torque||Drill Bit||Pull-Out (lbs.)|
|1/4” Short||1"||5 ft. lbs.||1/2''||150|
|5/16” Short||1-1/4"||7 ft. lbs.||1/2''||236|
|3/8” Short||1-3/4"||10 ft. lbs.||5/8''||442|
|1/2” Short||2"||20 ft. lbs.||3/4''||600|
|5/8” Short||2"||30 ft. lbs.||7/8"||641|
|3/4” Short||2"||40 ft. lbs.||1"||697|
|1/4” Long||1-1/2"||5 ft. lbs.||1/2''||225|
|5/16” Long||1-3/4"||7 ft. lbs.||1/2''||281|
|3/8” Long||2-1/2"||10 ft. lbs.||5/8''||555|
|1/2” Long||3"||20 ft. lbs.||3/4''||1095|
|5/8” Long||3-1/2"||30 ft. lbs.||7/8"||1297|
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.