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ABUSA

What the numbers mean

Every capacity figure on this site links here, because a number without its source is just a large font.

Four different things get called a number

They are not the same kind of claim and they do not answer the same question. Reading them as one number is how a hanger rated on a rig turns into a promise about a beam nobody has looked at.

On the carton

The figure the listing prints

A casting pulled on a rig until it lets go, one hanger at a time, with the load straight down through the loop. Nobody drilled wood for that test.

Public playgrounds

CPSC handbook number 325

Spacing, clear ground and fall surfaces for equipment on public land. It is guidance, not law for a backyard, and it gives no capacity number for hardware at all.

Voluntary

ASTM F1148

A consumer standard for home playground equipment sold as a set. It is voluntary, it is a paid document, and it is written around finished sets rather than a bag of hangers.

The actual limit

Span tables for the lumber

What a 4x6 carries over ten feet, and what a half inch lag holds in dry pine. This is the number that usually decides the answer, and it is the one nobody prints on a box.

What a rig test is

One casting, held in a fixture, pulled straight down through the loop until something gives. It tells you the metal is not the weak part, which is genuinely useful. It tells you nothing about a lag screw in forty year old pine, about a knot next to the hole you drilled, or about the sideways yank a nine year old puts through a swing going up the side of the frame.

Load in a real swing is not a steady weight either. A child pumping puts several times their own weight through the hardware at the bottom of the arc, in pulses, thousands of times a season. That is a fatigue question, and a single pull test is not designed to answer it.

What is regulated and what is not

Backyard swing hardware capacity is not set by any standard we can point you at. The CPSC handbook is written for public playgrounds and covers layout, clearances and fall surfacing rather than hardware ratings. ASTM F1148 is a voluntary consumer standard, behind a paywall, built around finished home sets. Neither one hands you a number for a hanger bolted to your own beam.

So when a catalogue prints a figure in a big font, the honest reading is attribution: that is what the maker measured, on their rig, on that part. It is not a certificate and it is not permission.

Where the real limit usually sits

In the beam and in the fixing. A 4x6 spanning ten feet, a half inch lag in dry pine, the depth of thread actually biting into sound wood: these decide the answer long before the casting is anywhere near its rig figure. The weakest link in a backyard swing is almost never the metal, and that is exactly why we do not lead with the metal figure.

What follows from that is practical. Look at the wood before you look at the hardware. Use the longest fixing that suits the timber. Put a wrench on it in spring, and look at the wood around each hole for a split running with the grain.

What we do and do not claim

  • We repeat the listing figure with its source named, and never as a rating for your install.
  • We do not say our hardware is tested to a standard, because no standard covers it.
  • We do not certify anything, and no page here is a safety approval.
  • We say what is in the carton and what is not, so a missing S hook is not a surprise.
  • Where published figures disagree, we print both and say who published each.

Notes that go into detail