Crosby D shackle
Crosby U-Bolts are manufactured from forged alloy steel, grade AISI 4140 or equivalent. Their surface hardness ranges from 35 to 40 HRC Rockwell C for optimal strength-toughness balance. Thread diameters range from M10 to M64 with standard ISO Metric Fine or Coarse thread pitch. Inside width center-to-center distance varies from 25 to 200 mm with a ±1 mm tolerance. Safe Working Load WLL ranges from 0.8 to 48 tons with a 4:1 or 5:1 safety factor. These fittings undergo quench and temper heat treatment for uniform mechanical properties.
The U-bolt structure features a semi-circular bent section with a specified inside radius and two parallel legs. The inside bend radius is typically designed at 55-60% of the nominal bolt diameter. The surface is often hot-dip galvanized with 80-120 micron thickness or electroless nickel-plated for corrosive environments. Companion nuts are Grade 8 or 10 steel per ISO 898-1, typically supplied with flat and lock washers. These fittings are tested and certified according to DIN 3570, ISO 3266 standards and Crosby specifications. Primary applications include wire rope terminations, pipe clamping, and load-bearing structural attachments.
