How to Determine the Correct Staple Leg Length

There are two basic considerations when choosing staple leg length: the thickness and the density of materials to be fastened. It is important to measure the depth of materials to be fastened before buying staples to determine appropriate leg length for desired results. The upholstery staple’s crown, after staple is applied, should be snug against the underlying surface and staple leg points should not protrude from the undersurface of the base material.

Standard Rule. An excellent rule for determining the correct staple length for your application is to take the thickness of the material you are attaching and multiply it by three. If the material is 3mm thick, for example, the staple should be 9mm in length. If the calculated depth of leg length is too long (and will protrude from the underlying material), choose the closest shorter leg length available.

Upholstery/thin material applications. When attaching fabric or other thin material, another approach to determining the staple leg length needed is to add 4mm to the thickness of the material being fastened. So, if your material is 3mm thick, choose a 7mm leg length for your staple. Again, if the calculated depth of leg length is too long (and will protrude from the underlying material), choose the closest shorter leg length available.

Factoring in wood density. When stapling uphostery fabric into hardwood*, approximately 3/16” to 1/4” penetration into the wood should be sufficient. For softwood** – up to approximately 3/8” penetration should be sufficient.

When joining two hard materials, however, such as maple to oak, using a staple with leg lengths twice as long as the material that needs fastening is recommended. If the calculated depth of leg length is too long (and will protrude from the underlying material), choose the closest shorter leg length available.