Craft · 6 pages · 12 min

Why a hem stiffens an edge

A hem folds the margin double so the rim behaves like a small stiff rib.

I understand the following: I can download a file of this brief, and I can also read it in the library on this browser. Clearing the cache or cookies deletes the library copy. The file must be downloaded for access to be retained.

When the purchase is complete, return to the original window. It will refresh.

From the opening

A hem stiffens an edge by folding the margin back on itself so the rim is a double thickness and the raw cut is hidden inside. The folded border resists bending far more than a single lip, because it has become a small rib. The opening covers the fold doubles the margin, the crease behaves like a rib, and the panel center stays thin.

The rest of the brief — the later sections and the reading notes — opens after Stripe confirms payment.

Inside

The fold doubles the margin
The crease behaves like a rib
The panel center stays thin
A wired curl adds a rod
Where the idea stops applying
A distinction worth keeping

Sources

Folded hem on sheet metal
Edge stiffness from a doubled rim

06The short physics of sourdoughCraft24 min$12 14How a library decides what to keepCraft24 min$12 0510How paper is made from fiberCraft12 min$20

Why a hem stiffens an edge

From the opening

Inside

Sources

Also on the desk