What are screw anchors?

What are screw anchors?

Power Driver Screw

Anchors are inserts, typically made from plastic, metal, or fiber, which enable the

attachment of screws into brittle materials — such as masonry or drywall. Known as wall

plugs in the UK, screw anchors are available in many forms and offer anchoring solutions

for different substrates at varying levels of strength.
    The most common type of Power Driver Screw Anchor Socket Type

is a tapered plastic tube that’s inserted into a closely fitting drilled hole and tapped

flush with the surface with a hammer. A hole in the center of the tube receives the screw

and, when tightened, it expands the tube radially outwards gripping the screw anchor

against the wall of the hole. Typically, the tube has slits in the base to facilitate its

expansion and ribs on the sides to prevent its rotation when tightening the screw.
    Screw anchors were invented by John Joseph Rawlings, a British Engineer in 1910, who

had been contracted by the British Museum to attach electrical fittings without causing

damage to their masonry walls. In response to the absence of any alternative to chiseling a

hole and hammering in a wooden block to nail or screw into, Rawlings solution was based on

the concept, “expansion means grip”.
    His Rawlplug was constructed from eight segments of jute arranged parallel to each

other to form a cylinder and held together with glue, the segments expanded apart from each

other when a Power Driver Screw Anchor Shaft Type was driven into the

center of the cylinder.
    The plastic screw anchor was invented in 1958 by Artur Fischer, a German inventor. The

Fischer Fixings Company still makes the original design — Fischer Expansion plug S — a

nylon anchor screw available in diameters of 4mm (1/8”) to 20mm (13/16”) for fixing light

objects in concrete and solid masonry.
   

Couplings fall into two main categories: Material Flexing and Mechanical Flexing. The

material flexible types obtain their flexibility from stretching or compressing a resilient

material, such as rubber, or from the flexing of thin metallic discs or grid. Material

flexing couplings do not require lubrication, with the exception of grid couplings.
    The Eye

Nuts are screwed together with a bolt or a screw to act as a fastening part. All

Anchor Rods,

Eyenuts&couplings that must be used in a manufacturing machine are classified into

several types of carbon steel, stainless steel, and non-ferrous metals (such as copper)

depending on the material. . The nut has the characteristics of easy installation,

integrity, no need of washers, easy disassembly and reusability made of medium carbon

steel.
    A Multi-

helix Earth Anchor/lead Section is an extendable deep foundation system with helical

bearing plates welded to a central steel shaft. Anchors are used in tension applications

and piles are used in compression applications. Load is transferred from the shaft to the

soil through these bearing plates.
    The No-wrench Screw

Anchors can be placed with power equipment or by hand. MPS No-Wrench Anchors are made

of a forged eye anchor rod with a welded helix and angle cut tip.
    These anchors are ideal for use in medium dense to loose soils. Final installed height

of the exposed anchor should be 8 to 12 inches above grade level. No-Wrench anchors are Hot

Dip Galvanized per ASTM A123.
  The design of Rock Anchors is

done to anchor structure to rock. Structures are anchored into the rock to maintain their

stability or carrying the loading on the structural elements such as walls, foundations,

etc. Different types of forces acting on the structures are transferred as tensile force or

comprehensive force or shear forces.
    Contractors of all kinds rely on concrete Post Anchors to provide secure and permanent placement for large motors,

pipes, structural framing, and a whole lot more. But when those anchors need to be removed,

as they often do, the process can often be difficult and labor-intensive. And even then,

they often don’t come off completely.