Flat Head Sleeve Anchors
A flat headed sleeve anchor is a special type of masonry fastener made up of four parts: an internal stud that is flared outwardly and cone shaped on one end with the other end threaded, a sleeve that fits over the internal stud, and a flat countersunk head that threads onto the stud. All parts of the flat-headed sleeve anchor are zinc plated and are packaged assembled.
The flat-headed sleeve anchor is an expansion-type anchor that works by turning the flat head clockwise, which pulls the cone shaped internally threaded stud upwards and expanding the sleeve against the walls of the hole in the base material.
The flat-headed sleeve anchor is one of the most versatile types masonry fasteners due to its use in most base materials. Because of the wide range of expansion, the flat-headed sleeve anchor works well in dense solid concrete to light hollow block as well as in solid brick and hollow brick.
The flat-headed sleeve anchor is available in three diameters of 1/4”, 5/16 and 3/8” with each diameter manufactured in different lengths. Both the 1/4” and 5/16” come with a slotted head, and the 3/8” comes in a flat Phillips head. The slotted head is designed for use with a slotted screwdriver and the Phillips head is designed for use with a Phillips drive screwdriver. The first number in the description refers to the diameter and the second number refers to the length of the flat-headed sleeve anchor. All flat headed sleeve anchor lengths are measured as an overall length which includes the head.
|Description||Part Number||Type of Drive|
|1/4” x 1-3/8”||SAF14138||Slotted|
|1/4” x 2”||SAF142||Slotted|
|1/4” x 3”||SAF143||Slotted|
|1/4” x 4”||SAF144||Slotted|
|5/16” x 2-1/2”||SAF516212||Slotted|
|5/16” x 3-1/2”||SAF516312||Slotted|
|3/8” x 4”||SAF384||Phillips|
|3/8” x 5”||SAF385||Phillips|
|3/8” x 5”||SAF386||Phillips|
The heads of flat-headed sleeve anchors are designed to be countersunk into the material that is being fastened down. Once installed, the head is flush with the surface of the fixture.
The flat-headed sleeve anchor is used in light to medium duty fastening; such as door frames to block walls or stair treads to concrete steps. All applications require that the head of the flat-headed sleeve anchor fits flush with the surface of the material being fastened.
Diameter of Hole
The diameter of the hole that is required to be drilled in the base material is dependent upon the diameter of flat-headed sleeve anchor being installed. The hole diameter is equal to the diameter of the flat headed sleeve anchor, i.e. a 1/4” flat headed sleeve anchor requires a 1/4” hole, a 5/16” requires a 5/16” hole and the 3/8” requires a 3/8” hole. The hole must be drilled using a hammer drill with the hammer drill set in the hammer and rotation mode. Carbide tipped masonry bit must be used in the hammer drill and the bit must meet ANSI standards. Hole tolerance is critical when installing flat-headed sleeve anchors; using an ANSI standard bit ensures matched tolerance between the hole diameter and the anchor diameter.
Determining Anchor Length
The minimum length for a flat-headed sleeve anchor to use is determined by adding the minimum embedment for the diameter of flat-headed sleeve anchor plus the thickness of the material being fastened. This will provide the minimum length of flat-headed sleeve anchor to use for any particular application.
Each diameter has a different minimum depth of embedment for the flat-headed sleeve anchor to obtain minimum holding values.
Spacing and Edge Distance
Each flat-headed sleeve anchor must be installed both a minimum distance from each other and a minimum distance from an unsupported edge. The rule of thumb for the concrete fasteners is to install them 10 anchor diameters away from each other and 5 anchor diameters from an unsupported edge.
Spacing Between Anchors
|Sleeve Anchor Diameter||Spacing|
|Sleeve Anchor Diameter||Edge Distance|
Fixture Hold Diameter
The diameter of the hole in the fixture must be slightly larger than the designated diameter of the flat-headed sleeve anchor being installed.
Fixture Hole Diameter
|Sleeve Anchor Diameter||Hole Diameter in Fixture|
Ultimate Holding Values in 2000-PSI Concrete
|1/4”||1-1/8”||5 ft/lbs||875 lbs.||1,430 lbs.|
|5/16”||1-7/16”||8 ft/lbs||1,110 lbs.||2,145 lbs.|
|3/8”||1-1/2”||15 ft/lbs||1,590 lbs.||3,060 lbs.|
- Drill a hole in the masonry base material with the correct diameter ANSI standard carbide bit. Drill the hole to a depth that will ensure 1/2” deeper than the flat-headed sleeve anchor will penetrate and is deeper than the minimum embedment requirements for the diameter being installed.
- Clean out the hole of all dust and debris.
- Insert flat headed sleeve anchor through the hole in the fixture and into the hole in the base material, tapping lightly with a hammer if needed.
- Using the proper screwdriver for the sleeve anchor, turn the head clockwise 2 to 3 turns until the specified torque is obtained.
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