ASTM A511 standard for mechanical stainless steel tubing

Seamless Stainless Steel Mechanical Tubing

This specification of ASTM A511 covers seamless stainless tubing for use in mechanical applications where corrosion-resistant or high-temperature strength is needed. The steel 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 tubes shall be made by a seamless process and by either cold working or hot working as specified. Seamless steel tubing is a tubular product made without a welded seam. It is usually manufactured by hot working steel and then cold finishing the hot-worked tubing to produce the desired shape, dimensions and properties

All austenitic tubes shall be furnished in the annealed condition. An analysis of each heat of steel shall be made to determine the percentages of the elements specified. If secondary melting processes are employed, the heat analysis shall be obtained from one remelted ingot or the product of one remelted ingot of each primary melt.

Chemical Requirements of Austenitic Stainless Steels：

Grade	Composition, %
	Carbon	Mn	P	S	Si, max	Ni	Cr	Mo	Ti	Columbium plus Tantalum	Se
		max	max	max
MT 302	0.08 to 0.20	2	0.04	0.03	1	8.0–10.0	17.0–19.0	...	...	...	...
MT 303	0.15 max	2	0.2	0.15 min	1	8.0–10.0	17.0–19.0	...	...	...	...
MT 303Se	0.15 max	2	0.04	0.04	1	8.0–11.0	17.0–19.0	...	...	...	0.12–0.2
MT 304	0.08 max	2	0.04	0.03	1	8.0–11.0	18.0–20.0	...	...	...	...
MT 304L	0.035 maxA	2	0.04	0.03	1	8.0–13.0	18.0–20.0	...	...	...	...
MT 305	0.12	2	0.04	0.03	1	10.0–13.0	17.0–19.0	...	...	...	...
MT 309S	0.08 max	2	0.04	0.03	1	12.0–15.0	22.0–24.0	...	...	...	...
MT 310S	0.08 max	2	0.04	0.03	1	19.0–22.0	24.0–26.0	...	...	...	...
MT 316	0.08 max	2	0.04	0.03	1	11.0–14.0	16.0–18.0	2.0–3.0	...	...	...
MT 316L	0.035 maxA	2	0.04	0.03	1	10.0–15.0	16.0–18.0	2.0–3.0	...	...	...
MT 317	0.08 max	2	0.04	0.03	1	11.0–14.0	18.0–20.0	3.0–4.0	...	...	...
MT 321	0.08 max	2	0.04	0.03	1	9.0–13.0	17.0–20.0	...	B	...	...
MT 347	0.08 max	2	0.04	0.03	1	9.0–13.0	17.0–20.0	...	...	C	...

Permissible Variations in Outside Diameter, Ovality, Wall Thickness, and Cut-Length Variations (Cold-Finished Round Tubing)

Outside Diameter, Tolerance,B in. Over and Under 　 0.005 0.005 0.01 0.015 0.03 0.045 0.062

Outside Diameter,in.	Ovality,B Double Outside Diameter Tolerance when wall is:	Wall Thickness in %C,D		Permissible Variations in Cut Length, in.E
		Over	Under	Over	Under
Under 1⁄2	less than 0.015 in.	15	15	1⁄8	0
1⁄2 to 11⁄2 , excl	less than 0.065 in.	10	10	1⁄8	0
11⁄2 to 31⁄2 , excl	less than 0.095 in.	10	10	3⁄16	0
31⁄2 to 51⁄2 , excl	less than 0.150 in.	10	10	3⁄16	0
51⁄2 to 8, exc	less than 0.240 in.	10	10	3⁄16	0
8 to 85⁄8 , excl	less than 0.300 in.	10	10	3⁄16	0
85⁄8 to 123⁄4 , incl	less than 0.350 in.	10	10	3⁄16	0

Permissible Variations in Outside Diameter, Wall Thickness, and Cut-Length Variations (Hot-Finished Round Tubing)

Specified Size, Outside Diameter, in.	Ratio of Wall Thickness to Outside Diameter	Outside Diameter and Wall Thickness Tolerances										Permissible Variations in Cut Length, in.A
		Wall Thickness, %
		Outside Diameter, in.		0.109 in. and under		0.109 to 0.172 in., incl		Over 0.172 to 0.203 in., incl		Over 0.203 in.
		over	under	over	under	over	under	over	under	over	under
Under 3	all wall thicknesses	0.023	0.023	16.5	15	15	15	14	14	12.5	12.5	3⁄16	0
3 to 51⁄2 , excl	all wall thicknesses	0.031	0.031	16.5	15	15	15	14	14	12.5	12.5	3⁄16	0
51⁄2 to 8, excl	all wall thicknesses	0.047	0.047	…	…	…	…	14	14	12.5	12.5	3⁄16	0
8 to 103⁄4 , excl	5 % and over	0.047	0.047	…	…	…	…	…	…	12.5	12.5	3⁄16	0
103⁄4 to 123⁄4 , incl	under 5 %	0.063	0.063	…	…	…	…	…	…	12.5	12.5	3⁄16	0

Straightness Tolerances (Cold-/Finished or Hot-/Finished Round Tubing)

Size Limits	Max Curvature in any 3 ft, in.	Max Curvature in Total Lengths, in.	Max Curvature for Lengths under 3 ft
OD 5 in. and smaller. Wall thickness, over 3 % of OD but not over 0.5 in.	0.03	0.030 3 [(Number of feet of length)/3]	Ratio of 0.010 in./ft
OD over 5 in. to 8 in., incl. Wall thickness, over 4 % of OD but not over 0.75in.	0.045	0.045 3 [(Number of feet of length)/3]	Ratio of 0.015 in./ft
OD over 8 in. to 123⁄4 , incl. Wall thickness, over 4 % of OD but not over 1 in.	0.06	0.060 3 [(Number of feet of length)/3]	Ratio of 0.020 in./ft

Permissible Variations in Outside Dimensions for Square and Rectangular Seamless Mechanical Tubing

Largest Outside Dimension Across Flats, in.	Tolerances, Outside Dimension Seamless Mechanical Tubing Plus and Minus, in.
	For Wall Thickness, Given, in.	Tolerance for Outside Dimension (Including Convexity or Concavity) Plus and Minus, in.
To 3⁄4 , incl	0.065 and lighter	0.015
To 3⁄4 , incl	over 0.065	0.01
Over 3⁄4 to 11⁄4 , incl	all thicknesses	0.015
Over 11⁄4 to 21⁄2 , incl	all thicknesses	0.02
Over 21⁄2 to 31⁄2 , incl	0.065 and lighter	0.03
Over 21⁄2 to 31⁄2 , incl	over 0.065	0.025
Over 31⁄2 to 51⁄2 , incl	all thicknesses	0.03
Over 51⁄2 to 71⁄2 , incl	all thicknesses	1%

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