Tunnel bolts are structural high-strength bolts that vary in size and grade depending on the application and bearing capacity.
Diameter 25mm -30mm
Surface: Galvanized and hot-dip galvanized
1、Square flange bolts with round thread for tunnel construction
Length from 400mm to 500mm
Tension strength is more than 700MPA
Surface: Yellow Zinc or according to clients' requirement
Packing: 600pcs in wooden case
2、Curved tunnel bolt
Dimension: 3/4-10 UNC2A
Length ranges 300mm to 500mm
Surface: HDG or according to clients' requirement
Packing: Plastic bags and wooden pallets
3、Spear bolts with plastic socket
Our spear tunnel bolt with plastic socket is manufactured according to customer's individual requirements. You can specify the length, diameter, steel grade, and choose from a range of surface finishes (e.g. galvanized, bright zinc plating, etc.). They can be supplied in grade 4.6 and 8.8.
Plastic socket sizes are available in:
M20 x 100, M20 x 120, M20 x 130, M20 x 135, M24 x 100, M24 x 110, , M24 x 120, M24 x 135, M24 x 140, M24 x 150, and M24 x 160.