An anchorage point is a secure attachment location where safety equipment connects to a structure to prevent or arrest a fall. In fall protection, OSHA defines it simply as “a secure point of attachment for equipment such as lifelines, lanyards, or deceleration devices.” It’s one of three essential components in a personal fall arrest system, alongside the body harness and the connector that links the two together. The term also appears in orthodontics, where it means something quite different, but the vast majority of people searching this phrase are working at height or managing a worksite.
How an Anchorage Point Works
When a worker falls from a roof, scaffold, or elevated platform, the chain of survival runs from their body harness, through a lanyard or lifeline, down to the anchorage point. That anchorage is what transfers the force of the fall into the building’s structure. If the anchorage fails, every other piece of equipment becomes useless. This is why anchorage points have the strictest load requirements of any component in the system.
An anchorage point must be independent of anything used to support or suspend a work platform. You cannot, for example, clip your harness to the same beam that’s holding up your scaffolding. The anchor also needs to be positioned above you, ideally directly overhead or as close to it as possible. When an anchor is off to the side, a fall produces a pendulum swing that can slam a worker into a wall, column, or the edge of the structure. This “swing fall” hazard is one of the most common mistakes in anchor placement.
Strength Requirements
OSHA requires every anchorage point to support at least 5,000 pounds per worker attached to it. If two workers clip into the same anchor, the structure must hold 10,000 pounds. That 5,000-pound figure is not the expected force of a typical fall, which is much lower. It’s a large safety margin designed to account for worst-case scenarios, rusted bolts, aging concrete, and the unpredictable dynamics of a real fall.
There is one alternative to the 5,000-pound rule: an anchor can be rated lower if it’s designed, installed, and used under the supervision of a qualified person as part of a complete fall protection system that maintains a safety factor of at least two. In practice, this means the system can withstand twice the maximum force it would ever experience during a fall arrest. Window cleaning anchors have an even higher threshold of 6,000 pounds minimum.
The structural material behind the anchor matters just as much as the anchor hardware itself. A concrete substrate typically needs to be at least 2,000 psi in compressive strength and six inches thick. Steel decking should be a minimum of 20 gauge. Wood substrates require at least 3/4-inch thickness. The underlying member must be able to handle that 5,000-pound load regardless of what kind of anchor hardware sits on top of it.
Types of Anchorage Points
Anchorage points fall into two broad categories: permanent and temporary. Permanent anchors are bolted, welded, or embedded into a structure and stay in place for the life of the building. Temporary anchors are portable devices that clamp, wrap, or fasten onto existing structural elements for a single job or shift, then get removed.
Permanent Anchors
Roof anchors are the most common permanent type. These are typically metal plates with a D-ring, bolted through the roof decking into structural members below. Concrete anchors use threaded rods or expansion bolts set directly into poured concrete. Standing seam roof clamps grip the raised seams of metal roofing without penetrating the surface, which avoids creating leak points. Parapet anchors clamp onto the low walls at the edges of flat roofs. For buildings with regular window maintenance, dedicated window washing anchor points are permanently installed near the roofline.
Temporary Anchors
Beam clamps are the workhorse of temporary fall protection. These devices wrap around or clamp onto steel I-beams and H-beams without any drilling or welding. One common model fits beams ranging from 3.5 inches to 14 inches wide and up to 1.25 inches thick. Tie-back anchors use webbing slings wrapped around a structural column or beam. Metal decking anchors grip corrugated steel roof panels. Door and window frame anchors brace against the inside of an opening to create an attachment point in finished interiors.
Where to Position an Anchor
The ideal position for an anchorage point is directly above the worker, as high as possible. This minimizes both the total fall distance and the risk of a swing fall. Every foot of horizontal offset between you and your anchor increases the arc of a potential pendulum swing and adds to the total distance your body travels before the system stops you.
Fall clearance is the other critical calculation. You need enough open space below the anchor for the full length of your lanyard, the stretch of your shock absorber (which can extend several feet), your own height, and a safety buffer so you don’t hit the ground or a lower level. On powered industrial trucks or mobile platforms, OSHA requires the anchor to be attached to an overhead member of the platform, positioned above and near the center of the work area.
Inspection and Maintenance
Every anchorage point should be visually inspected before each use. For permanent anchors, look for cracks in the surrounding concrete or substrate, corrosion on metal components, loose or missing bolts, and any signs of deformation. An anchor that has arrested a fall needs to be taken out of service and professionally evaluated before anyone clips into it again, because the forces involved can cause invisible damage to both the hardware and the underlying structure.
Temporary anchors need the same scrutiny. Check that clamp mechanisms tighten fully, that webbing slings show no fraying or cuts, and that the structural member you’re attaching to is sound. The anchor hardware is only as reliable as what it’s connected to. A perfectly good beam clamp on a corroded or undersized beam is a failing system.
Regulatory Standards
OSHA sets the legal minimums for anchorage points in two main standards: 29 CFR 1926.502 for construction and 29 CFR 1910.140 for general industry. Both require the 5,000-pound-per-worker capacity or the supervised safety-factor-of-two alternative.
Beyond OSHA, the ANSI/ASSE Z359.18 standard covers anchorage connectors in more detail. Published in 2017, it establishes requirements for performance, design, testing, marking, and instructions for use across multiple applications: fall arrest, travel restraint, rescue, work positioning, rope access, and suspended systems. Equipment that meets this standard will be labeled accordingly. If you’re selecting anchor hardware for a jobsite, looking for that Z359.18 marking is a straightforward way to confirm the product has been independently tested.
Anchorage in Orthodontics
The term “anchorage point” also comes up in orthodontics, where it refers to the source of resistance that makes tooth movement possible. When braces push a tooth in one direction, something has to resist the equal and opposite force, or everything shifts and nothing moves where it should. That resistance source is the anchorage.
Traditionally, orthodontists used groups of teeth, headgear, or the palate as anchorage. More recently, Temporary Anchorage Devices (TADs) have become a common tool. These are small screws placed directly into the jawbone during treatment. They provide a fixed, immovable point that forces can push or pull against, allowing more precise tooth movement than relying on other teeth for resistance. TADs are loaded immediately after placement and removed once treatment is complete.