k1: Height of the square neck section under the head
Carriage Bolts (also known as Round Head Square Neck Bolt/ Cup Head Square Neck Bolt/ Coach Bolt/ DIN 603 Bolt/ Kart Bolt) are fastening bolts with a smooth domed head and a square or knurled neck. The neck locks into a mating hole to prevent rotation, allowing the head to seat flush while the nut is tightened from the other side. Typically blunt-tipped, they are hammer-set and widely used in wood-to-wood, wood-to-metal, and some metal-to-metal joints.
GB/T 12: Small semi-round head square neck bolt
GB/T 14: Large semi-round head square neck bolt
DIN 603: Equivalent to large semi-round head square neck bolts
Carbon Steel: Class 4.8, 5.8, 8.8, 10.9
Stainless Steel: A2-70, A4-70, A4-80 (304 / 316 stainless)
Alloy Steel / Galvanized Steel for heavy-duty use
Metric: M5 – M20 (lengths up to 300mm)
Inch: 1/4" – 3/4" diameter (lengths up to 12")
Woodworking: Beam-to-post, decking, furniture
Porte: grade 8.8 yellow zinc plated carriage bolt, China grade 8.8 yellow zinc plated carriage bolt manufacturers, suppliers
