Specifications

Competitive price Precision CDS honed tube
telescopic tube
DOM honing tube
honed h8 cylinder steel tube
hon

Competitive price Precision CDS honed tube

 

Seamless precision steel tubes are used variously:
• equipment engineering 

• elevator tubes
• gas cylinders
• pit props
• hydraulic lines
• chain pipes
• bicycle/ motorcycle frames
• rivets
• pumps
• technical machinery
• cylinder, piston and telescopic tubes
• stabiliser tubes
• gear box tubes
• drive shaft tubes

 

Tubes for automotive industry:
• axles for gearboxes
• fuel injection lines
• piston bolts
• ball cages
• steering wheel shafts column tubes
• power-assisted steering tubes   

 

DIN 2391-1: Seamless precision steel tubes  

  

This standard specifies dimensions for cold finished, seamless precision steel tubes. The preferred sizes listed are mainly used in mechanical and automotive engineering. 

  

Steel Grade	Chemical Composition(%)
	C max	Si max	Mn	P max	S max
St35	0.17	0.35	≥0.40	0.025	0.025
St45	0.21	0.35	≥0.40	0.025	0.025
St52	0.22	0.55	≥0.40	0.025	0.025

  

Mechanical properties

  

Steel grade	BK		BKW		BKS			GBK		NBK
	Tensile Strength Rm N/mm min	Eloga-tion A % min	Tensile Strength Rm N/mm min	Eloga-tion A % min	Tensile Strength Rm N/mm min	Yield Strength ReH N/mm min	Eloga-tion A % min	Tensile Strength Rm N/mm min	Eloga-tion A % min	Tensile Strength Rm N/mm min	Yield Strength ReH N/mm min	Eloga-tion A % min
St35	480	6	420	10	420	315	14	315	25	340-470	235	25
St45	580	5	520	8	520	375	12	390	21	440-570	235	21
St52	640	4	580	7	580	420	10	490	22	490-630	355	22

  

Designation	Symbol	Description
Cold finished (hard)	BK	Tubes do not undergo heat treatment following the final cold forming and, thus, have a rather high resistance to deformation.
Cold finished (soft)	BKW	The final heat treatment is followed by cold drawing involving limited deformation. Appropriate further processing allows a certain degree of cold forming. (e.g. bending, expanding).
Cold finished and stress-relieved	BKS	Heat treatment is applied following the last cold forming process. Subject to appropriate processing conditions, the increase in the residual stresses involved enables both forming and machining to a certain degree.
Annealed	GBK	The last cold forming process is followed by annealing in a controlled atmosphere.
Normalized	NBK	The last cold forming process is followed by annealing above the upper transformation point in a controlled atmosphere.

• Mill test certificates will be issued according to EN10204/3.1B
• Packing: Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.
• Inspection and Test: Chemical Composition Inspection, Mechanical Properties Test(Tensile Strength,Yield Strength, Elongation, Flaring, Flattening, Bending, Hardness, Impact Test), Surface and Dimension Test, No-destructive Test, Hydrostatic Test.
• Surface treatment: Oiled, black painted, hot dipped galvanized or phosphate coating as required.
• Both ends of each crate will indicate the order no., heat no., dimensions, weight and bundles or as requested.
• 
• Any Intrest or need, please feel free to contact us!