Hydraulic support tube:
1.Macrostructure is tested according to GB226,and the average grain size is no less then Class5;
2.Non-metallic inclusion is evaluated by JK method per GB/T10561
3.Materials used for the tube are usually 27SiMn,30MnNbRe and etc,physical properties of 27SiMn at quench &temper condition:tensile stength 800Mpa,yielding strength 680Mpa,elongation 15%,area reduction 40%,impact 39J,hardness 240-280HB;
4. Precision of dimension is of IT9-14 class,and the roundness of inner surface is less than 0.15%-0.3% of the nominal size;
5. thickness measured at any section along the length direction of steel pipe does not exceed 8% of the nominal wall thickness;
6.straightness is less than 0.3-0.6mm/m,surface roughness Ra1.6-6.3,maximum length 16500mm;
7.other technical specifications are implemented accofding to GB17396-2009.
8.With independent intellectual property right.