ASTM A519 Steel Tube

This pipe covers for several grades of carbon and alloy steel mechanical tubing, either hot-finished or cold-finished. The steel used in the mechanical tubing may be cast in ingots or may be strand cast. When steel of different grades is sequentially strand cast, identification of the resultant transition material is required. The seamless tubing is a tubular product made without a welded seam. It is usually manufactured by hot working steel, and if necessary, by subsequently cold finishing the hot-worked tubular product to produce the desired shape, dimensions and properties.

The tubes shall be furnished in the following shapes: round, square, rectangular and special sections. Heat analysis shall be made to determine the percentages of the elements specified. If secondary melting processes are used, the heat analysis shall be obtained from one remelted ingot or the product of one remelted ingot of each primary melt. The tubing shall be coated with a film of oil before shaping to retard rust when specified.

Characteristic Features of ASTM A519 Pipes

1. Tubes under ASTM A 519 specification can be round, square, rectangular, or spiral, depending on the client's demands.
2. Any pipe claiming to be an ASTM A 519-grade pipe must meet the specification requirements. This entails top-notch finishing devoid of laps, cracks, seams, and other forms of a defect.
3. This specification offers standards for hot finished and cold finished seamless pipes with an Outside Diameter (OD) up to 12 3/4 inches.
4. The steel used under this specification may be cast from ingots or be strand cast.
5. The permissible variation in the squareness tolerance of square/ rectangular tubing is achieved using the formula +/-b = c X 0.006.
6. Square or rectangular tubing under ASTM A 519 specs are allowed a variation of 0.060 within 3 feet of the tubing.
7. Clients can specify the tubes to be coated with rust-resisting oil before shaping. If they so wish, the product can retain this coating well till the shipping process.
8. The Wall Thickness (WT) of ASTM A 519 tubing is between 2mm to 120mm.
9. These pipes/tubes typically have a bevelled or a plain end.
10. Tests like non-destructive quality tests, flaring tests, hardness tests, and tension tests are some examinations conducted to check the tube quality. Aside from these, this piping is also checked for cleanliness and hardenability.

Dimension Tolerances:

Pipe Type	Pipe Sizes		Tolerances
Cold drawn	OD	≤48.3mm	±0.40mm
	WT	≥60.3mm	±1%mm

Chemical Composition:

Chemical Requirements of Carbon Steels:

Grade Designation	Chemical Composition Limits, %
	Carbon	Manganese	Phosphorus,max	Sulfur,max
1008	0.10 max	0.30–0.50	0.040	0.050
1010	0.08–0.13	0.30–0.60	0.040	0.050
1018	0.15–0.20	0.60–0.90	0.040	0.050
1020	0.18–0.23	0.30–0.60	0.040	0.050
1025	0.22–0.28	0.30–0.60	0.040	0.050
1026	0.22–0.28	0.60–0.90	0.040	0.050
1035	0.32–0.38	0.60–0.90	0.040	0.050
1040	0.37–0.44	0.60–0.90	0.040	0.050
1045	0.43–0.50	0.60–0.90	0.040	0.050
1050	0.48–0.55	0.60–0.90	0.040	0.050

Chemical Requirements of Resulfurized or Rephosphorized, or Both, Carbon Steels:

Grade Designation	Chemical Composition Limits, %
	Carbon	Manganese	Phosphorus	Sulfur	Lead
1118	0.14–0.20	1.30–1.60	0.040 max	0.08–0.13	/
1137	0.32–0.39	1.35–1.65	0.040 max	0.08–0.13	/

Chemical Requirements for Alloy Steels:

Grade Designation	Chemical Composition Limits, %
	Carbon	Manganese	Phosphorus, C max	Sulfur, C,D max	Silicon	Nickel	Chromium	Molybdenum
4130	0.28–0.33	0.40–0.60	0.040	0.040	0.15–0.35	…	0.80–1.10	0.15–0.25
4135	0.32–0.39	0.65–0.95	0.040	0.040	0.15–0.35	…	0.80–1.10	0.15–0.25
4140	0.38–0.43	0.75–1.00	0.040	0.040	0.15–0.35	…	0.80–1.10	0.15–0.25
4145	0.43–0.48	0.75–1.00	0.040	0.040	0.15–0.35	…	0.80–1.10	0.15–0.25

Mechanical Properties:

Grade Designation	Condition	Tenslle Strength,		Yield Strength,		Elongationin 2 in. or 50 mm, %	Rockwell,Hardness B Scale
		ksi	MPa	ksi	MPa
1020	HR	50	345	32	221	25	55
	CW	70	483	60	414	5	75
	SR	65	448	50	345	10	72
	A	48	331	28	193	30	50
	N	55	379	34	234	22	60
1025	HR	55	379	35	241	25	60
	CW	75	517	65	448	5	80
	SR	70	483	55	379	8	75
	A	53	365	30	207	25	57
	N	55	379	36	248	22	60
1035	HR	65	448	40	276	20	72
	CW	85	586	75	517	5	88
	SR	75	517	65	448	8	80
	A	60	414	33	228	25	67
	N	65	448	40	276	20	72
1045	HR	75	517	45	310	15	80
	CW	90	621	80	552	5	90
	SR	80	552	70	483	8	85
	A	65	448	35	241	20	72
	N	75	517	48	331	15	80
1050	HR	80	552	50	345	10	85
	SR	82	565	70	483	6	86
	A	68	469	38	262	18	74
	N	78	538	50	345	12	82
1118	HR	50	345	35	241	25	55
	CW	75	517	60	414	5	80
	SR	70	483	55	379	8	75
	A	50	345	30	207	25	55
	N	55	379	35	241	20	60
1137	HR	70	483	40	276	20	75
	CW	80	552	65	448	5	85
	SR	75	517	60	414	8	80
	A	65	448	35	241	22	72
	N	70	483	43	296	15	75
4130	HR	90	621	70	483	20	89
	SR	105	724	85	586	10	95
	A	75	517	55	379	30	81
	N	90	621	60	414	20	89
4140	HR	120	855	90	621	15	100
	SR	120	855	100	689	10	100
	A	80	552	60	414	25	85
	N	120	855	90	621	20	100

ASTM A519 steel pipe is manufactured by cold drawing process or hot finishing process. Cold drawn seamless tubes have tighter dimensional tolerances and better concentration of mechanical properties. Hot finished tubes retain better mechanical properties, but are more expensive to manufacture.

Finishing rolling process: 
Finishing rolling is a process to obtain higher precision and better surface quality by rolling the heat-treated seamless steel pipe multiple times. The specific steps include: heat treatment - pickling - cooling - finishing rolling - sizing - cutting - length - inspection - packaging. Finishing rolling can improve the precision, surface quality and mechanical properties of steel pipe.

Cold drawing process: 
Cold drawing is a process of drawing the heat-treated seamless steel pipe one by one in a cold state to obtain high precision, high surface quality and high mechanical properties. The specific steps include: heat treatment - pickling - cooling - cold drawing - deoxygenation - wet pickling - cold water washing - leveling - straightening - pickling - cold water washing - oxide skin - cold drawing - sizing - straightening - pickling - cold water washing - deoxygenation - polishing - inspection - packaging. Cold drawing can significantly improve the dimensional accuracy, surface quality and mechanical properties of steel pipes.

For ASTM A519 steel pipe, three types of tests are performed to ensure quality: mechanical, hydrostatic, and eddy current. Mechanical testing includes testing properties such as yield strength, tensile strength, and elongation. Hydrostatic testing checks for leaks by performing a pressure test. Eddy current testing looks for defects in the grain structure of metals by using electromagnetic fields. ASTM A519 steel pipe can be heat treated to increase the strength and toughness of the material.