The LD-431 flat wire U staples are precision-formed to the 131 series standard, featuring a consistent 12.3mm crown width and five leg length options from 6mm up to 14mm. The flat wire construction (0.7 x 1.2mm cross-section) provides a wider bearing surface than round wire staples, which distributes clamping force more evenly across fabric, paper, and thin wood materials. This makes the 131 series the preferred staple profile for office stapling, light upholstery work, and craft applications where surface marking must be minimized.

The galvanized high carbon steel wire is zinc-plated to provide reliable corrosion resistance for indoor and covered-environment use. The zinc coating prevents red rust formation during storage and use, extending shelf life and preserving the clean appearance of finished work. For applications exposed to moisture or tannin-rich hardwoods, the series can also be specified with copper plating, which further reduces the risk of staining on light-colored woods and fabrics.

The five leg length options (6mm, 8mm, 10mm, 12mm, 14mm) allow precise matching to material thickness. As a general rule, leg length should be approximately 3 times the thickness of the material being fastened: 6mm legs suit 2mm paper and fabric layers, 8-10mm legs handle thin cardboard and single-ply wood, and 12-14mm legs secure thicker fabric sandwiches, leather, and picture frame back panels. Choosing the correct leg length ensures a secure clinch on the reverse side without excessive protrusion.

The LD-431 staples are compatible with standard manual and pneumatic staplers that accept 131 series flat wire crowns, including popular office, light-duty furniture, and craft stapler brands. Each inner box contains 1,000 pieces, and 50 boxes are packed per master carton for efficient wholesale distribution. Mixed orders across leg lengths are supported, and OEM packaging, custom box quantities, and private label branding are available for distributor programs.