1. Scope
1.1 This specification covers welded stainless steel tubing for mechanical applications where appearance, mechanical properties, or corrosion resistance is needed. The grades covered are listed in Table 1.
1.2 This specification covers as-welded or cold-reduced mechanical tubing in sizes to 16 in. (406.4 mm) outside dimension, and in wall thicknesses 0.020 in. (0.51 mm) and over.
1.3 Tubes shall be furnished in one of the following shapes as specified by the purchaser: round, square, rectangular, or special.
1.4 Supplementary requirements of an optional nature are provided and when desired shall be so stated in the order.
1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
TABLE 1 Chemical Requirements
Grade
| Composition, %
|
|---|
Carbon,
max
| Manga-
nese,
max
| Phos-
phorus,
max
| Sulfur,
max
| Silicon,
max
| Nickel
| Chromium
| Molybdenum
| Titanium
| Columbium + Tantalum
|
|---|
Austenitic
|
| MT-301 | 0.15 | 2.00 | 0.040 | 0.030 | 1.00 | 6.0–8.0 | 16.0–18.0 | ... | ... | ... |
| MT-302 | 0.15 | 2.00 | 0.040 | 0.030 | 1.00 | 8.0–10.0 | 17.0–19.0 | ... | ... | ... |
| MT-304 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 8.0–11.0 | 18.0–20.0 | ... | ... | ... |
| MT-304L | 0.035A | 2.00 | 0.040 | 0.030 | 1.00 | 8.0–13.0 | 18.0–20.0 | ... | ... | ... |
| MT-305 | 0.12 | 2.00 | 0.040 | 0.030 | 1.00 | 10.0–13.0 | 17.0–19.0 | ... | ... | ... |
| MT-309S | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 12.0–15.0 | 22.0–24.0 | ... | ... | . . . |
| MT-309S-Cb | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 12.0–15.0 | 22.0–24.0 | ... | ... | B |
| MT-310S | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 19.0–22.0 | 24.0–26.0 | ... | ... | ... |
| MT-316 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 10.0–14.0 | 16.0–18.0 | 2.0–3.0 | ... | ... |
| MT-316L | 0.035A | 2.00 | 0.040 | 0.030 | 1.00 | 10.0–15.0 | 16.0–18.0 | 2.0–3.0 | ... | ... |
| MT-317 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 11.0–14.0 | 18.0–20.0 | 3.0–4.0 | ... | ... |
| MT-321 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 9.0–13.0 | 17.0–20.0 | ... | C | ... |
| MT-330 | 0.15 | 2.00 | 0.040 | 0.030 | 1.00 | 33.0–36.0 | 14.0–16.0 | ... | ... | ... |
| MT-347 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 9.0–13.0 | 17.0–20.0 | ... | ... | B |
Ferritic
|
| 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-430-Ti | 0.10 | 1.00 | 0.040 | 0.030 | 1.00 | 0.075 max | 16.0–19.5 | ... | 5 × C min, | ... |
| | | | | | | | | 0.75 max | |
A For small diameter or thin walls, or both, where many drawing passes are required, a carbon content of 0.040 % max is necessary in grades MT-304L and MT-316L. Small outside diameter tubes are defined as those less than 0.500 in. (12.7 mm) in outside diameter and light wall tubes as those less than 0.049 in. (1.24 mm) in average wall thickness.
B The columbium plus tantalum content shall be not less than ten times the carbon content and not more than 1.00 %.
C The titanium content shall be not less than five times the carbon content and not more than 0.60 %.
2. Referenced Documents (purchase separately) 
The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
Military Standards
MIL-STD-163 Steel Mill Products Preparation for Shipment and Storage
Federal Standard
Fed.Std.No.123 Marking for Shipments (Civil Agencies)
Keywords
austenitic stainless steel; exhaust tubing; ferritic stainless steel tubing; mechanical tubing; ornamental tubing; stainless steel tube; steel tube; structural tubing; welded steel tube: Austenitic stainless steel tube--specifications; Corrosive service applications--tube (steel); Mechanical tubing--specifications; Stainless steel tube--specifications; Welded steel tube--specifications;
ICS Code
ICS Number Code 23.040.10 (Iron and steel pipes); 23.040.40 (Metal fittings)
DOI: 10.1520/A0554-08A
ASTM International is a member of CrossRef.
Citing ASTM Standards
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