Machine Screw Anchors
Masonry Anchors for use with Machine Screws and Bolts
Also known as caulk-in anchors, these medium-duty anchors work much like drop-in anchors but are used with machine screws to securely anchor fixtures to masonry materials. The malleable sleeve helps the anchor fill imperfections in the hole by expanding and distributing the load evenly across the anchor. After installation, the anchor remains in the material, allowing fixtures to be removed or replaced without sacrificing holding power.
Machine Screw Anchors are used with machine screws or bolts to anchor fixtures to concrete or masonry materials. Like many concrete anchors, machine screw anchors are installed into pre-drilled holes in masonry materials and set using a unique tool. As the screw is tightened, it pulls up a wedge at the anchor's bottom, which expands the sleeve to fit snugly in the pre-drilled hole. Machine screw anchors are safe for concrete, brick, or block and fill uneven or irregular spots in the hole. The screws or bolts can be removed from the anchor and reinstalled later without replacing the anchor.
FAQs
What is a machine screw anchor?
Machine screw anchors are a type of drop-in anchor designed to be installed in various base materials, including concrete, brick, and block. They have a malleable sleeve to help fill imperfections in the drilled hole and a shallow embedment requirement so you can spend less time drilling with shorter holes. Machine screw anchors are intended to be used with machine screws and bolts, which can be removed and reinserted without losing the anchor's holding power.
How is a machine screw anchor different from a drop-in anchor?
The main difference between drop-in anchors and machine screw anchors is their applications. Drop-in anchors are best suited for solid concrete. In contrast, machine screw anchors can be installed in a wide range of masonry materials, including concrete, brick, and block.
How do you install machine screw anchors?
Drill the hole for the anchor, clean the drilled hole out of the dust, drop the anchor in, and set it with a setting tool by placing the tool in the anchor and tapping it with a hammer. This will secure the machine screw anchor to the base material. For more specifics on drill size to use and the minimum embedment required, along with other specifications for a given machine screw anchor, please refer to the below table. Note that machine screw anchors are sized based on the screw diameter and threading they can accept.
| Size: | Drill Diameter: | Installation Torque: | Minimum Embedment: | Performance - 4000psi Concrete: | Performance - C90 Hollow Block: | Performance - Solid Red Brick: |
| #10-24 | 3/8" | Max 20 in. lbs. | 5/8 | Tensile: 1340 lbs. Shear: 1200 lbs. | Tensile: 740 lbs. Shear: 1130 lbs. | Tensile: 1050 lbs. Shear: 1140 lbs. |
| 1/4"-20 | 1/2" | Max 60 in. lbs. | 7/8 | Tensile: 2340 lbs. Shear: 1800 lbs. | Tensile: 880 lbs. Shear: 1340 lbs. | Tensile: 1460 lbs. Shear: 1580 lbs. |
| 5/16"-18 | 5/8" | Max 7 ft. lbs. | 1 | Tensile: 3020 lbs. Shear: 2640 lbs. | Tensile: 1820 lbs. Shear: 1700 lbs. | Tensile: 1730 lbs. Shear: 2140 lbs. |
| 3/8"-16 | 3/4" | Max 10 ft. lbs. | 1-1/4 | Tensile: 4810 lbs. Shear: 4220 lbs. | Tensile: 2280 lbs. Shear: 2430 lbs. | Tensile: 2200 lbs. Shear: 3870 lbs. |
| 1/2"-13 | 7/8" | Max 15 ft. lbs. | 1-1/2 | Tensile: 5930 lbs. Shear: 5800 lbs. | Tensile: 2360 lbs. Shear: 3440 lbs. | Tensile: 3270 lbs. Shear: 4860 lbs. |
Machine screw anchors shall not be removable or show evidence of failure when subjected to tensile and shear test loads as specified in the above table. The suggested safe working load is one-fourth the average test proof loads shown in the above table.
Do I have to use a setting tool to install machine screw anchors?
Yes. A setting tool must be used to install machine screw anchors to ensure they are set properly.
Can I set machine screw anchors below the surface of a base material?
Yes, machine screw anchors can be set below the surface of base materials. Just be sure the setting tool for installing them can still reach the anchor once it's dropped into the hole.
