Technical Specifications for Machine Screw Anchors
Purchase Machine Screw Anchors
There are numerous technical specifications that must be considered when using the Machine Screw Anchor. including: diameter, internal thread length, minimum embedment and required hole size. Machine screw anchors are a great fastener when irregular hole sizes are a concern. The size of the anchor refers to the diameter of the machine screw or 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.
Length:
To determine the minimum length of machine bolt required, add the thickness of the material being fastened to the Machine Screw anchor length.
Spacing:
The forces on a Machine Screw 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 of the anchor. 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.) |
| #8 | 1/2” | 15 in. lbs. | 5/16” | 251 |
| #10 | 5/8” | 20 in. lbs. | 3/8” | 573 |
| 1/4” | 7/8” | 60 in. lbs. | 1/2” | 879 |
| 5/16” | 1” | 7 ft. lbs. | 5/8” | 1177 |
| 3/8” | 1-1/4” | 10 ft. lbs. | 3/4” | 1488 |
| 1/2” | 1-1/2” | 15 ft. lbs. | 7/8” | 2096 |
| 5/8” | 1-3/4” | 18 ft. lbs. | 1-1/8” | 2132 |
| 3/4” | 2-1/4” | 20 ft. lbs. | 1-1/4” | 2310 |
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.