Pls send us your best offer for seamless alloy steel tubes for structural use, GB/t 1862-1999, grade #45, tensile strength 680mpa, diameter (outer/inner in mm): 30/18, 8; 33/20; 37/23; 41/25, 5; 45/28, 5; 51/31.

Quantity: About 5t each type.