ASTM A511/A511M-21a

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A511/A511M − 21 A511/A511M − 21a
Standard Specification for
Seamless Stainless Steel Mechanical Tubing and Hollow
Bar
This standard is issued under the fixed designation A511/A511M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*
1.1 This specification covers seamless stainless tubing for use in mechanical applications or as hollow bar for use in the production
of hollow components such as, but not limited to nozzles, reducers, and couplings by machining where corrosion-resistant or
high-temperature strength is needed. The grades covered are listed in Table 1 , Table 2, and Table 3.
1.2 This specification covers seamless cold-finished mechanical tubing and hollow bar and seamless hot-finished mechanical
tubing and hollow bar in sizes up to 12 ⁄4 in. [325 mm] in outside nominal diameter (for round tubing) with wall thicknesses or
inside diameters as required.
1.3 Tubes for mechanical applications shall be furnished in one of the following shapes, as specified by the purchaser: round,
square, rectangular, or special. Tubes to be used as hollow bar shall be furnished in round shape.
1.4 Optional supplementary requirements are provided and when desired, shall be stated in the order.
1.5 The values stated in inch-pound units are to be regarded as the standard. Within the text, the SI units are shown in square
brackets. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the
other.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A1016/A1016M Specification for General Requirements for Ferritic Alloy Steel, Austenitic Alloy Steel, and Stainless Steel
Tubes
A1058 Test Methods for Mechanical Testing of Steel Products—Metric
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.10
on Stainless and Alloy Steel Tubular Products.
Current edition approved Sept. 1, 2021Nov. 1, 2021. Published October 2021November 2021. Originally approved in 1964. Last previous edition approved in 20202021
as A511/A511M – 20.A511/A511M – 21. DOI: 10.1520/A0511_A0511M-21.10.1520/A0511_A0511M-21A.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A511/A511M − 21a
TABLE 1 Chemical Requirements of Austenitic Stainless Steels
Composition, %
Phos- Sul-
Other
Grade
Manga- pho- fur, Silicon,
D
Carbon Nickel Chromium Molybdenum Titanium Niobium Selenium Iron Elements
nese rus, max max
max
MT 302 0.08 to 0.20 2.00 max 0.040 0.030 1.00 8.0–10.0 17.0–19.0 . . . . . .
MT 303 0.15 max 2.00 max 0.20 0.15 min 1.00 8.0–10.0 17.0–19.0 . . . . . .
MT 303Se 0.15 max 2.00 max 0.040 0.040 1.00 8.0–11.0 17.0–19.0 . . . 0.12–0.2 . .
MT 304 0.08 max 2.00 max 0.040 0.030 1.00 8.0–11.0 18.0–20.0 . . . . . .
A
MT 304L 0.035 max 2.00 max 0.040 0.030 1.00 8.0–13.0 18.0–20.0 . . . . . .
MT 305 0.12 2.00 max 0.040 0.030 1.00 10.0–13.0 17.0–19.0 . . . . . .
MT 309S 0.08 max 2.00 max 0.040 0.030 1.00 12.0–15.0 22.0–24.0 . . . . . .
MT 310S 0.08 max 2.00 max 0.040 0.030 1.00 19.0–22.0 24.0–26.0 . . . . . .
MT 316 0.08 max 2.00 max 0.040 0.030 1.00 11.0–14.0 16.0–18.0 2.0–3.0 . . . . .
A
MT 316L 0.035 max 2.00 max 0.040 0.030 1.00 10.0–15.0 16.0–18.0 2.0–3.0 . . . . .
MT 317 0.08 max 2.00 max 0.040 0.030 1.00 11.0–14.0 18.0–20.0 3.0–4.0 . . . . .
MT 321 0.08 max 2.00 max 0.040 0.030 1.00 9.0–13.0 17.0–20.0 . 5XC – . . . .
0.60
MT 347 0.08 max 2.00 max 0.040 0.030 1.00 9.0–13.0 17.0–20.0 . . 10XC – 1.00 . . .
N08020 0.070 max 2.00 max 0.045 0.035 1.00 32.0–38.0 19.0–21.0 2.00–3.00 . 8XC – 1.00 . . Cu 3.00–4.00
N08367 0.030 max 2.00 max 0.040 0.030 1.00 23.5–25.5 20.0–22.0 6.00–7.00 . . . . N 0.18–0.25
Cu 0.75
B
N08800 0.10 max 1.50 max 0.045 0.015 1.00 30.0–35.0 19.0–23.0 . 0.15–0.60 . . 39.5 min Al 0.15–0.60
Cu 0.75
B
N08810 0.05–0.10 1.50 max 0.045 0.015 1.00 30.0–35.0 19.0–23.0 . 0.15–0.60 . . 39.5 min Al 0.15–0.60
Cu 0.75
C B C
N08811 0.06–0.10 1.50 max 0.045 0.015 1.00 30.0–35.0 19.0–23.0 . 0.25–0.60 . . 39.5 min Al 0.25–0.60
Cu 0.75
N08904 0.020 max 2.00 max 0.040 0.030 1.00 23.0–28.0 19.0–23.0 4.0–5.0 . . . . N 0.10
Cu 1.00–2.00
N08925 0.020 max 1.00 max 0.045 0.030 0.50 24.0–26.0 19.0–21.0 6.0–7.0 . . . . N 0.10–0.20
Cu 0.80–1.50
N08926 0.020 max 2.00 max 0.030 0.010 0.50 24.0–26.0 19.0–21.0 6.0–7.0 . . . . N 0.15–0.25
Cu 0.40–1.50
S20910 0.06 max 4.0-6.0 0.045 0.030 1.00 11.5-13.5 20.5-23.5 1.50-3.00 { 0.10-0.30 { { N 0.20-0.40
V 0.10-0.30
A
For small diameter or thin wall tubing or both, where many drawing passes are required, a maximum of 0.040 % carbon is necessary in grades MT-304L and MT-316L. Small outside diameter tubes are defined as those
under a 0.500 in. [12.7 mm] outside diameter and light-wall tubes as those under a 0.049 in. [1.2 mm] average wall thickness (0.044 in. [1.1 mm] min wall thickness).
B
Iron shall be determined arithmetically by difference of 100 minus the sum of the other specified elements.
C
The range of (Al + Ti) shall be within 0.85–1.20 %.
D
The terms Niobium (Nb) and Columbium (Cb) are alternate names for the same element.

A511/A511M − 21a
TABLE 2 Chemical Requirements of Ferritic and Martensitic Stainless Steels
Composition, %
Manga- Phos- Sulfur,
Grade
Silicon, Molyb-
Carbon, max nese, phorus, max Nickel Chromium Aluminum Copper Nitrogen Selenium
max denum
max max
Martensitic
MT 403 0.15 1.00 0.040 0.030 0.50 0.50 max 11.5–13.0 0.60 max
MT 410 0.15 1.00 0.040 0.030 1.00 0.50 max 11.5–13.5 . . . . .
MT 414 0.15 1.00 0.040 0.030 1.00 1.25–2.50 11.5–13.5 . . . . .
MT 416Se 0.15 1.25 0.060 0.060 1.00 0.50 max 12.0–14.0 . . . . 0.12–0.20
MT 431 0.20 1.00 0.040 0.030 1.00 1.25–2.50 15.0–17.0 . . . . .
MT 440A 0.60 to 0.75 1.00 0.040 0.030 1.00 . 16.0–18.0 0.75 max . . . .
Ferritic
MT 405 0.08 1.00 0.040 0.030 1.00 0.50 max 11.5–14.5 . 0.10–0.30 . . .
MT 429 0.12 1.00 0.040 0.030 1.00 0.50 max 14.0–16.0 . . . . .
MT 430 0.12 1.00 0.040 0.030 1.00 0.50 max 16.0–18.0 . . . . .
MT 443 0.20 1.00 0.040 0.030 1.00 0.50 max 18.0–23.0 . . 0.90–1.25 . .
MT 446–1 0.20 1.50 0.040 0.030 1.00 0.50 max 23.0–30.0 . . . 0.25 max .
A
MT 446–2 0.12 1.50 0.040 0.030 1.00 0.50 max 23.0–30.0 . . . 0.25 max .
29-4 0.010 0.30 0.025 0.020 0.20 0.15 max 28.0–30.0 3.5–4.2 . 0.15 max 0.020 max .
B
29-4-2 0.010 0.30 0.025 0.020 0.20 2.0–2.5 28.0–30.0 3.5–4.2 . 0.15 max 0.020 max .
A
MT446-2 is a lower carbon version of MT446-1, that has a lower tensile strength but improved ductility and toughness.
B
Carbon plus nitrogen = 0.025 max %.
A
TABLE 3 Chemical Requirements of Austenitic-Ferritic Stainless Steels
Grade Composition, %
Carbon Manganese, Phosphorus, Sulfur, max Silicon, max Nickel Chromium Molybdenum Nitrogen Copper Other
max max Elements
S31260 0.030 1.00 0.030 0.030 0.75 5.5–7.5 24.0–26.0 2.5–3.5 0.10–0.30 0.20–0.80 W 0.10–0.50
S31803 0.030 2.00 0.030 0.020 1.00 4.5–6.5 21.0–23.0 2.5–3.5 0.08–0.20 . .
S32101 0.040 4.0–6.0 0.040 0.030 1.00 1.35–1.70 21.0–22.0 0.10–0.80 0.20–0.25 0.10–0.80 .
S32205 0.030 2.00 0.030 0.020 1.00 4.5–6.5 22.0–23.0 3.0–3.5 0.14–0.20 . {
S32304 0.030 2.50 0.040 0.040 1.00 3.0–5.5 21.5–24.5 0.05–0.60 0.05–0.20 0.05–0.60 .
S32506 0.030 1.00 0.040 0.015 0.90 5.5–7.2 24.0–26.0 3.0–3.5 0.08–0.20 . W 0.05–0.30
S32550 0.040 1.50 0.040 0.030 1.00 4.5–6.5 24.0–27.0 2.9–3.9 0.10–0.25 1.50–2.50 .
S32707 0.030 1.50 0.035 0.010 0.50 5.5–9.5 26.0–29.0 4.0–5.0 0.30–0.50 1.0 Co 0.5–2.0
S32750 0.030 1.20 0.035 0.020 0.80 6.0–8.0 24.0–26.0 3.0–5.0 0.24–0.32 0.50 .
B
S32760 0.05 1.00 0.030 0.010 1.00 6.0–8.0 24.0–26.0 3.0–4.0 0.20–0.30 0.50–1.00 W 0.50–1.00
S32906 0.030 0.80-1.50 0.030 0.030 0.80 5.8–7.5 28.0–30.0 1.50–2.60 0.30–0.40 0.80 .
S32808 0.030 1.10 0.030 0.010 0.50 7.0–8.2 27.0–27.9 0.80–1.20 0.30–0.40 { W 2.10–2.50
S32950 0.030 2.00 0.035 0.010 0.60 3.5–5.2 26.0–29.0 1.00–2.50 0.15–0.35 . .
S39274 0.030 1.00 0.030 0.020 0.80 6.0–8.0 24.0–26.0 2.5–3.5 0.24–0.32 0.20–0.80 W 1.50–2.50
A
Maximum, unless a range or minimum is indicated. Where ellipses ({) appear in this table, there is no requirement and analysis for the element need not be determined
or reported.
B
% Cr + 3.3 X % Mo + 16X % N $ 40.
E112 Test Methods for Determining Average Grain Size
2.2 Military Standards:
MIL-STD-129 Marking for Shipment and Storage
MIL-STD-163 Steel Mill Products Preparation for Shipment and Storage
2.3 Federal Standard:
Fed. Std. No. 123 Marking for Shipments (Civil Agencies)
3. Terminology
3.1 Definitions:
3.1.1 hollow bar—round tubing that is intended to produce engineering components by machining, generally specified by
minimum outside diameter and maximum inside diameter.
3.1.2 mechanical tubing—tubing of various shapes used for mechanical and general engineering purposes, specified by nominal
outside dimension and nominal wall.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
A511/A511M − 21a
4. Ordering Information
4.1 Orders for material under this specification should include the following as required to describe the desired material
adequately:
4.1.1 Quantity (feet, mass, or number of pieces),
4.1.2 Name of material (seamless stainless steel mechanical tubing or hollow bar),
4.1.3 Mechanical Tubing Form only (round, square, rectangular, special, see Section 1),
4.1.4 Dimensions (round, nominal outside diameter and nominal wall thickness, (see 11.1 and 11.2) or minimum outside diameter
and maximum inside diameter (see 11.3); square and rectangular, nominal outside dimensions and nominal wall thickness, see
Section 12; other, specify),
4.1.5 Length (specific or random, see 11.4),
4.1.6 Manufacture (cold- or hot-finished, see 6.5),
4.1.7 Grade (Section 8),
4.1.8 Condition (annealed, as cold worked, or with special heat treatment, controlled microstructural characteristics, or other
condition as required, see Section 7),
4.1.9 Surface finish (special pickling, shot blasting, or polishing, as required, see Supplementary Requirement S5),
4.1.10 Specification designation,
4.1.11 Report of Chemical Analysis, if required (Sections 9 and 10),
4.1.12 Individual supplementary requirements, if required,
NOTE 1—Supplementary requirements S1 and S2 are required for hollow bar only (see Section 13).
4.1.13 End use,
4.1.14 Packaging,
4.1.15 Special marking (see 18.2),
4.1.16 Special packing (see 19.2), and
4.1.17 Special requirements.
5. General Requirements
5.1 Material furnished under this specification shall conform to the applicable requirements of the current edition of Specification
A1016/A1016M unless otherwise provided herein.
6. Materials and Manufacture
6.1 The steel may be made by any process.
6.2 If a specific type of melting is required by the purchaser, it shall be as stated on the purchase order.
A511/A511M − 21a
6.3 The primary melting may incorporate separate degassing or refining and may be followed by secondary melting, such as
electroslag remelting or vacuum-arc remelting. If secondary melting is employed, the heat shall be defined as all of the ingots
remelted from a single primary heat.
6.4 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 producer shall remove the transition material by an established procedure that
positively separates the grades.
6.5 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.
7. Condition
7.1 Round seamless stainless mechanical tubing is generally supplied in the cold-worked and annealed condition (see 7.2 through
7.5). Square, rectangular, or other shapes of tubing are generally supplied annealed prior to final cold shaping. If some other
condition is desired, details shall be included in the order. Round seamless hollow bar is generally applied in the hot-worked and
annealed condition.
7.2 The thermal treatment for ferritic and martensitic steels shall be performed by a method and at a temperature selected by the
manufacturer unless otherwise specified by the purchaser.
7.3 Unless otherwise specified, all austenitic mechanical tubing and hollow bar, except for UNS N08020 shall be furnished in the
solution annealed condition. Unless otherwise specified in Table 4, the solution anneal shall consist of heating the material to a
minimum temperature of 1900 °F [1040 °C] and quenching in water or rapidly cooling by other means. Alternatively, immediately
following hot forming while the temperature of the mechanical tubing or hollow bar is not less than the specified minimum solution
treatment temperature, tubes may be individually quenched in water or rapidly cooled by other means. This solution anneal shall
precede final cold work, when cold-worked tempers are required. UNS N08020 shall be furnished in the stabilized annealed
condition.
7.4 All austenitic-ferritic mechanical tubing and hollow bar shall be furnished in the solution annealed condition as prescribed in
Table 5. Alternatively, immediately following hot forming, while the temperature of the mechanical tubing or hollow bar is not
less than the specified minimum solution treatment temperature, tubes may be individually quenched in water or rapidly cooled
by other means.
7.5 If any controlled microstructural characteristics are required, these shall be specified so as to be a guide to the most suitable
heat treatment.
8. Chemical Composition
8.1 The steel shall conform to the requirements as to chemical composition prescribed in Table 1, Table 2, or Table 3. Other grades
are available.
TABLE 4 Heat Treatment of Austenitic Stainless Steels
Grade Temperature °F [°C] Quench
A,B
N08020 1700–1850 [925–1010] quenched in water or rapidly cooled by other means
A
N08367 2025 [1105] quenched in water or rapidly cooled by other means
A
N08810 2050 [1120] quenched in water or rapidly cooled by other means
A
N08811 2100 [1150] quenched in water or rapidly cooled by other means
A
N08904 2000 [1100] quenched in water or rapidly cooled by other means
A
N08925 2010–2100 [1100–1150] quenched in water or rapidly cooled by other means
A
N08926 2010–2100 [1100–1150] quenched in water or rapidly cooled by other means
A
Quenched in water or rapidly cooled by other means, at a rate sufficient to prevent re-precipitation of carbides, as demonstrable by the capability of tubes, heat treated
by either separate solution annealing or by direct quenching, passing Practices A262, Practice E. The manufacture is not required to run the test unless it is specified on
the purchase order. Note that Practices A262 requires the test to be performed on sensitized specimens in the low-carbon and stabilized types and on specimens
representative of the as-shipped condition for other types. In the case of low-carbon types containing 3 % or more molybdenum, the applicability of the sensitizing treatment
prior to testing shall be a matter for negotiation between the seller and the purchaser.
B
Material shall be supplied in stabilized annealed condition.
A511/A511M − 21a
TABLE 5 Heat Treatment of Austenitic-Ferritic Stainless Steels
Grade Temperature °F [°C] Quench
S31260 1870-2010 [1020-1100] rapid cooling in air or water
S31803 1870-2010 [1020-1100] rapid cooling in air or water
S32101 1870 [1020] min quenched in water or rapidly cooled by other means
S32205 1870-2010 [1020-1100] rapid cooling in air or water
S32304 1700-1920 [925-1050] rapid cooling in air or water
S32506 1870-2050 [1020-1120] rapid cooling in air or water
S32550 1900 [1040] min rapid cooling in air or water
S32707 1975-2050 [1080-1120] rapid cooling in air or water
S32750 1880-2060 [1025-1125] rapid cooling in air or water
S32760 1960-2085 [1070-1140] rapid cooling in air or water
S32808 1920-2100 [1050-1150] rapid cooling in air or water
S32906 1870-2100 [1020-1150] rapid cooling in air or water
S32950 1820-1880 [990-1025] air cool
S39274 1880-2060 [1025-1125] rapid cooling in air or water
9. Heat Analysis
9.1 An analysis of each heat of steel shall be made by the steel manufacturer 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. The chemical composition thus determined, or that determined from a product analysis
made by the tubular product manufacturer, shall be reported to the purchaser or the purchaser’s representative and shall conform
to the requirements specified. When requested in the order or contract, a report of this analysis shall be furnished to the purchaser.
10. Product Analysis
10.1 An analysis of either one billet or one tube shall be made for each heat of steel. The chemical composition thus determined
shall conform to the requirements specified in Section 8.
10.2 If the original test for product analysis fails, retests of two additional billets or tubes shall be made. Both retests, for the
elements in question, shall meet the requirements of the specification, otherwise all remaining material in the heat or lot shall be
rejected or, at the option of the producer, each billet or tube may be individually tested for acceptance. Billets or tubes which do
not meet the requirements of this specification shall be rejected.
11. Permissible Variations in Dimensions of Round Mechanical Tubing and Hollow Bar
11.1 Nominal Outside Diameter and Nominal Wall Thickness (Cold Finished Mechanical Tubing and Hollow Bar)—
Variations in outside diameter and wall thickness shall not exceed the amounts prescribed in Table 6.
11.2 Nominal Diameter and Nominal Wall Thickness (Hot Finished Mechanical Tubing and Hollow Bar)—
Variations in outside diameter and wall thickness shall not exceed the amounts prescribed in Table 7.
11.3 Minimum Outside Diameter and Maximum Inside Diameter (Cold-Finished and Hot-Finished Hollow Bar)—Variations in
outside diameter and wall thickness shall not exceed the amounts prescribed in Table 8.
11.4 Lengths (Cold Finished or Hot Finished)—Mechanical tubing and hollow bar are commonly furnished in mill lengths 5 ft
[1.5 m] and over. When random lengths are ordered, mechanical tubing and hollow bar lengths may vary by an amount up to 7
ft [2.1 m]. Definite cut lengths are furnished, when specified, to the length tolerances shown in Table 6 or Table 7. For mechanical
tubing and hollow bar ordered in multiple lengths, it is common practice to allow a definite amount over for each multiple for the
purchaser’s cutting operations. This amount depends on the type of purchaser’s cutting and varies with differing wall thickness.
The cutting allowance should be specified on the purchase order. When it is not specified, mechanical tubing and hollow bar are
customarily supplied with the following allowance for each multiple:
Excess Length
Wall Thickness, per Multiple,
in. [mm] in. [mm]
1 1
Up to ⁄8 [3.2] ⁄8 [3]
1 1 3
Over ⁄8 to ⁄2 [3.2 to 12.7] ⁄16 [5]
1 1
Over ⁄2 [12.7] ⁄4 [6]
A511/A511M − 21a
TABLE 6 Permissible Variations in Outside Diameter, Ovality, Wall Thickness, and Cut-Length Variations
A
(Cold-Finished Round Mechanical Tubing and Hollow Bar)
B
Prevailing Outside Ovality, Double Permissible
Outside
Range of Diameter, Variations
Diameter
B
Commercially Tolerance, Wall Thickness in Cut
Outside
Tolerance
C,D E
in. [mm] Over
Available in % Length, in. [mm]
Nominal
when
and Under
Metric Sizes,
wall is:
Diameter,
mm
in. [mm]
Over Under Over Under
1 1
Under ⁄2 [13] Under 12.7 0.005 [0.1] less than 0.015 in. 15 15 ⁄8 [3] 0
[0.4 mm]
1 1 1
⁄2 [13] to 1 ⁄2 12.7 to 38.1, excl 0.005 [0.1] less than 0.065 in. 10 10 ⁄8 [3] 0
[38], excl [1.6 mm]
1 1 3
1 ⁄2 [38] to 3 ⁄2 38.1 to 88.9 excl 0.010 [0.3] less than 0.095 in. 10 10 ⁄16 [5] 0
[90], excl [2.4 mm]
1 1 3
3 ⁄2 [90] to 5 ⁄2 88.9 to 139.7, excl 0.015 [0.4] less than 0.150 in. 10 10 ⁄16 [5] 0
[140], excl [3.8 mm]
1 3
5 ⁄2 [140] to 8 139.7 to 203.2, excl 0.030 [0.8] less than 0.240 in. 10 10 ⁄16 [5] 0
[200], excl [6.1 mm]
5 3
8 [200] to 8 ⁄8 203.2 to 219.1, excl 0.045 [1.1] less than 0.300 in. 10 10 ⁄16 [5] 0
[220], excl [7.6 mm]
5 3
8 ⁄8 [220] to 219.1 to 323.9, incl 0.062 [1.6] less than 0.350 in. 10 10 ⁄16 [5] 0
12 ⁄4 [325], incl [8.9 mm]
A
1 5
Tolerances of tubes produced by the rod or bar mandrel process and which have an inside diameter under ⁄2 in. [12.7 mm] (or an inside diameter under ⁄8 in. [15.8 mm] when the wall thickness is more than 20 % of
the outside diameter) are as shown in this table, except that wall thickness tolerances are 10 % over and under the specified wall thickness.
B
For ovality values, the tolerance for average outside diameter at any one cross section does not exceed the outside diameter tolerance value for the applicable outside diameter.
C
Many tubes with wall thicknesses more than 25 % of outside diameter or with wall thicknesses over 1 ⁄4 in., [31.7 mm] or weighing more than 90 lb/ft [60.5 kg/m], are difficult to draw over a mandrel. Therefore, the wall
thickness can vary 12 ⁄2 % over and under that specified. Also see Footnote (B).
D
1 5
For those tubes with inside diameter under ⁄2 in. [12.7 mm] (or under ⁄8 in. [15.8 mm] when the wall thickness is more than 20 % of the outside diameter) which are not commonly drawn over a mandrel, Footnote (A)
is not applicable. Therefore, the wall thickness can vary 15 % over and under that specified, and the inside diameter is governed by both the outside diameter and wall thickness tolerances.
E
These tolerances apply to cut lengths up to and including 24 ft. [7.3 m]. For lengths over 24 ft [7.3 m], an additional over tolerance of ⁄8 in. [3 mm] for each 10 ft [3 m] or fraction thereof shall be permissible, up to a
maximum tolerance of ⁄2 in. [13 mm].

A511/A511M − 21a
TABLE 7 Permissible Variations in Outside Diameter, Wall Thickness, and Cut-Length Variations
(Hot-Finished Round Mechanical Tubing and Hollow Bar)
Prevailing Outside Diameter and Wall Thickness Tolerances Permissible Variations
A
in Cut Length, in. [mm]
Specified Range
Ratio of Wall
Nominal Inch of
Wall Thickness, %
Thickness to
Size, Outside Commercially Outside
Outside
0.109 in. [2.77 mm] 0.109 [2.77] to Over 0.172 [4.37] to
Diameter, in. Available Diameter, in. [mm]
Over 0.203 in. [5.16 mm]
Diameter
and under 0.172 in. [4.37 mm], incl 0.203 in. [5.16 mm], incl
[mm] Metric
Sizes, mm Over Under Over Under Over Under Over Under Over Under
Under 3 [75] Under 76.1 all wall 0.023 [0.6] 0.023 [0.6] 16.5 16.5 15 15 14 14 12.5 12.5 ⁄16 [4.8] 0
thicknesses
1 3
3 [75] to 5 ⁄2 76.1 to all wall 0.031 [0.8] 0.031 [0.8] 16.5 16.5 15 15 14 14 12.5 12.5 ⁄16 [4.8] 0
[140], excl 139.7, excl thicknesses
1 3
5 ⁄2 [140] to 8 139.7 to all wall 0.047 [1.2] 0.047 [1.2] . . . . 14 14 12.5 12.5 ⁄16 [4.8] 0
[200], excl 203.2, excl thicknesses
8 [200] to 203.2 to 5 % and 0.047 [1.2] 0.047 [1.2] . . . . . . 12.5 12.5 ⁄16 [4.8] 0
10 ⁄4 [275], 273.1, excl over
excl
3 3
10 ⁄4 [275] to 273.1 to under 5 % 0.063 [1.6] 0.063 [1.6] . . . . . . 12.5 12.5 ⁄16 [4.8] 0
12 ⁄4 [325], 323.9, incl
incl
A
These tolerances apply to cut lengths up to and including 24 ft [7.3 m]. For lengths over 24 ft [7.3 m], an additional over tolerance of ⁄8 in. [3 mm] for each 10 ft [3 m] or faction thereof shall be permissible, up to a maximum
tolerance of ⁄2 in. [13 mm].
A511/A511M − 21a
TABLE 8 Permissible Variations in Minimum Outside Diameter and Maximum Inside Diameter (Cold-Finished and Hot-Finished Round
Hollow Bar)
Minimum Outside Tolerance on Outside Diameter in. [mm] Maximum Inside Tolerance on Inside Diameter in. [mm]
Diameter (D) in. [mm] Diameter (d) in. [mm]
Over Under Over Under
D < 2 [50] 0.04 [1] 0.00 [0] d < 2 [50] 0.00 [0] 0.04 [1]
A
D $ 2 [50] 0.02 D 0.00 [0] d < 2 [50] 0.00 [0] 0.04 [1]
A B
D $ 2 [50] 0.02 D 0.00 [0] d $ 2 [50] 0.00 [0] 0.02 d
A
Calculate value: 2 % × Specified Minimum Outside Diameter.
B
Calculate value: 2 % × Specified Maximum Inside Diameter.
11.5 Straightness Tolerances (Cold Finished or Hot Finished Mechanical Tubing)—The deviation from straightness shall not
exceed the amounts shown in Table 9 when measured with a 3-ft [1-m] straightedge and feeler gauge. If determined by the dial
indicator method, the values obtained will be approximately twice those determined by the straightedge feeler gauge method.
11.6 Straightness Tolerances (Cold Finished or Hot Finished Hollow Bar—The dev
...