What makes one wood shipping crate stronger than another? You might guess that it’s the thickness of the lumber or the size of the nails used to fasten the planks together.

Starting with quality materials is always important, but two crates made with very similar materials can have vastly different levels of durability. The trick is in the technique used to construct the crates.

The secret to building super-strong shipping crates? Clinching the nails.

Here’s how the dictionary defines the word:

clinch [klinch] verb

  1. to settle a matter decisively
  2. to secure a nail in position by beating down the protruding point

In the case of shipping crates, using the technique in the second definition actually achieves the first definition. Crates with clinched nails are most decidedly stronger than those constructed using standard nailing techniques.

Choose the Right Fastener

Some crate builders will use nails that are just short of the total depth of the two pieces of lumber they are nailing together. This prevents the points of the nails from protruding past the surface of the crate and damaging the product being shipped or snagging an unsuspecting worker. However, the crate will be far less sturdy than a one built with longer nails.

Longer nails allow for clinching. A longer nail can be driven through the two pieces of wood, so the head is flush with the outside surface. Whatever length of nail extends beyond the inside surface of the wood can then be hammered flat to the surface or bent at two right angles, so that the point of the nail is buried in the wood.

A Visible Difference

Unlike some measures of the quality of shipping crates, it is easy to spot a crate with clinched nails. Here’s what the inside of a crate looks like when the points of the nails have been bent back into the surface of the wood (clinched nails circled in green):

Clinched Nails In Wood

The Angle on Strength

Clinching increases the holding power of the nail significantly which yields a much stronger crate.  To understand how bending the nail produces such a benefit, consider a standard office supply: staples. Just like a nail is used to hold the sides of a shipping crate together, a staple is designed to pierce the surface of several pieces of paper and hold them secure no matter which direction the pages are flipped or tugged.

A stapler drives the staple into stack of papers and clinches the ends, folding them almost flat against the back of the paper. Without that clinching action, the papers might stay together for a short time on an unbent staple, but any amount of page-turning or filing would likely result in pages fluttering free.

Nails driven straight into wood will certainly hold longer than a malfunctioning staple in a stack of papers. But shipping crates constructed with un-clinched nails run the risk of loosening up as they are lifted, nudged, tugged, and stacked during their journey.

Clinching the nails essentially locks the parts of the crate together so they will stand up better to the wear-and-tear of the handling that occurs during transport.

How to Clinch a Crate

The protruding tips of nails can be clinched by hand with a hammer, but that would be an especially time-intensive task when building a shipping crate.

At CDC Packaging, we use steel nailing tables to ensure that each nail is clinched as we assemble our wooden crates and skids.

Nailing Table

Each nail is driven through the material being assembled and into the steel surface of the table. When the point of the nail hits the steel, it bends flat to the surface of the wood.

CDC Packaging Nails It!

Clinching the nails produces stronger, more durable, shipping crates. That’s why CDC Packaging makes sure to construct every crate on the steel nailing table. Contact us today to experience the difference clinching can make.