Detailed Introduction to Grid Bolt

Detailed Introduction to Grid Bolt

Basic Information Bar:

Chinese name: High strength bolt for grid structure

Foreign name: Highstrength bolts for joints of space grid structure

Material Classification: Grid Accessories

Material: 20MnTiB, 40Cr, 35CrMo, 35VB

1、 Overview

High strength bolts for grid structures are a type of bolts used in steel structures. They are only used in bolted ball grid structures and grid shell structures, and are therefore different from the commonly used high strength bolts.

Solid shape

The special feature of high-strength bolts in the grid structure is that there is a sliding groove on the screw and a deep groove near the head, which is where the fastening screws (pins) on the matching "sleeve" (plain nut) are embedded. Due to the embedding of the pins, when installing, turning the wrench can drive the bolts to screw into the bolt ball, while the pins slide in the sliding groove. When the bolts are tightened in place, the fastening screws are exactly in the position of the deep groove, At this point, tighten the fastening screw to allow it to fall into the deep groove, achieving the effect of stopping and preventing loosening.

Material and performance

The performance level of high-strength bolts for grid structures is related to the bolt diameter, with a small diameter of 10.9 and a large diameter of 9.8. The material is also related to the diameter, as shown in the figure:

Accessory Relationship

The figure shows the relationship between high-strength bolts and sleeves, fastening screws, members, and bolt balls in the bolted ball grid node.

Type and specifications

The thread specifications of high-strength bolts for grid structures range from M12 to M64, as shown in the "High strength bolts for steel grid bolt ball joints GB/T16939-1997". Among them, bolts below M20 are mostly used in decorative grid structures.

Due to the fixed interrelationships in the construction of nodes, the screw length of each specification of high-strength bolts in the grid is also fixed, as detailed in relevant materials.

Because the high-strength bolts and sleeves of the grid frame are matched, the bolt specifications are determined based on the calculation of the sleeve pressure during node design for the compression members.