ASTM A268 / ASME SA268 / Seamless and Welded Ferritic Stainless Steel Tubing supplier & distributor in India

ASTM A268

SEAMLESS AND WELDED FERRITIC STAINLESS STEEL TUBING FOR GENERAL SERVICE

This standard is issued under the fixed designation A 268; 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 ( ε) indicates an editorial change since the last revision or reapproval.

1. Scope

1.1 This specification² covers a number of grades of nominal-wall-thickness, stainless steel tubing for general corrosion-resisting and high-temperature service. Most of these grades are commonly known as the "straight-chromium" types and are characterized by being ferromag-netic. Two of these grades, TP410 and UNS S41500 (Table1), are amenable to hardening by heat treatment, and the high-chromium, ferritic alloys are sensitive to notch-brit-tleness on slow cooling to ordinary temperatures. These features should be recognized in the use of these materials.
Grade TP439 is used primarily for hot-water tank service and does not require post-weld heat treatment to prevent attack of the heat affected zone.

NOTE 1-TP329 (S32900) formerly in this specification. has been transferred to Specifications A 789/A 789M and 790/A 790M.

1.2 An optional supplementary requirement is provided,and when desire, shall be so stated in the order.

NOTE 2-For tubing smaller than 1/2 in. [12.7 mm] in outside diameter, the elongation values given for strip specimens in Table 2 shall apply. Mechanical property requirements do not apply to tubing smaller than 1/8 in. [3.2mm] in outside diameter or with walls thinner than 0.015 in. [0.4 mm].

1.3 The values stated in either inch-pound units or SIunits are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the "M" designation of this specification is specified in the order.

Grade			Remaks (Similar to JIS)	Possibility Temperature
Grade			Remaks (Similar to JIS)	Possibility Temperature
TP405	-	-	(SUS 405TB)
TP410	-	-	-
TP429	-	-	(SUS 430TB)
TP430	-	-	-
TP443	-	-	-
TP446-1	-	-	-
TP446-2	-	-	-
S40800	-	-	-
TP409	-	-	-
S41500	-	-	-
TP439	-	-	-
TP430Ti	-	-	(SUS XM27TB)
TPXM-27	-	-	-
XM-33	-	-	-
18Cr-2Mo	-	-	-
29-4	-	-	-
29-4-2	-	-	-
26-3-3	-	-	-
25-4-4	-	-	-
S44735	-	-	-

Chemical Requirements

NOTE - TP329(S32900), formerly part of this specification, has been transferred to A 789/A 789M.

Grade	TP 405	TP 410	TP 429	TP 430	TP 443	TP 446-1	TP 446-2A	...	TP 409
UNS DesignationB	S40500	S41000	S42900	S43000	S44300	S44600	S44600	S40800	S40900
Element	Composition, %
C, max	0.18	0.15	0.12	0.12	0.20	0.20	0.12	0.08	0.08
Mn, max	1.00	1.00	1.00	1.00	1.00	1.50	1.50	1.00	1.00
P, max	0.040	0.040	0.040	0.040	0.040	0.040	0.040	0.045	0.045
S, max	0.030	0.030	0.030	0.030	0.030	0.030	0.030	0.045	0.045
Si, max	0.75	0.75	0.75	0.75	0.75	0.75	0.75	1.00	1.00
Ni	0.50max	0.50max	0.50max	0.50max	0.50max	0.50max	0.50max	0.80max	0.50max
Cr	11.5-13.5	11.5-13.5	14.0-16.0	16.0-18.0	18.0-23.0	23.0-30.0	23.0-30.0	11.5-13.0	10.50-11.75
Mo	...	...	...	...	...	...	...	...	...
Al	0.10-0.30	...	...	...	...	...	...	...	...
Cu	...	...	...	...	0.90-0.25	...	...	...	...
N	...	...	...	...	...	0.10-0.25	0.10-0.25	...	...
Ti	...	...	...	...	...	...	...	12xC min; 1.10max	6xC min; 0.75max

Grade	TP 439	...	TP 430 Ti	TP XM-27	TP XM-33D	18Cr-2Mo	29-4	26-4-2	26-3-3	25-4-4	...C
UNS Designation	S43035	S41500c	S43036	S44627	S44626	S44400	S44700	S44800	S44660	S44635	S44735
Element	Composition, %
C, max	0.07	0.05	0.10	0.01D	0.06	0.025	0.010	0.010	0.030	0.025	0.030
Mn, max	1.00	0.5-1.0	1.00	0.40	0.75	1.00	0.30	0.30	1.00	1.00	1.00
P, max	0.040	0.03	0.040	0.02	0.040	0.040	0.025	0.025	0.040	0.040	0.040
S, max	0.030	0.03	0.030	0.02	0.020	0.030	0.020	0.020	0.030	0.030	0.030
Si, max	1.00	0.60	1.00	0.40	0.75	1.00	0.20	0.20	1.00	0.75	1.00
Ni	0.050max	3.5-5.5	0.75max	0.5Fmax	0.50max	1.00max	0.15max	2.0-2.5	1.0-3.50	3.5-4.5	1.00max
Cr	17.00-19.00	11.5-14.0	16.00-19.50	25.0-27.5	25.0-27.0	17.5-19.5	28.0-30.0	28.0-30.0	25.0-28.0	24.5-26.0	28.00-30.00
Mo	...	0.5-1.0	...	0.75-1.50	0.75-1.50	1.75-2.50	3.5-4.2	3.5-4.2	3.0-4.0	3.5-4.5	3.60-4.20
Al, max	0.15	...	...	...	...	...	...	...	...	...	...
Cu, max	...	...	...	0.2	0.20	...	0.15	0.15	...	...	...
N, max	0.04	...	...	0.015	0.040	0.035	0.020G	0.020G	0.040	0.035	0.045
Ti	0.20+4 (C+N)min; 1.10max	...	5xC min; 0.75max	...	7x(C+N)but no less than 0.20min; 100max	(TI+Cb) 0.20+4 (C+N) min; 0.80 max	...	...	(Ti+Cb)= 0.20-1.00 and 6x(C+N) min	(Ti+Cb)= 0.20+4 (C+N) min to 0.80max	(Ti+Cb)= 0.20-1.00 with 6(C+N)min
Cb	...	...	...	0.05-0.20	...	...	...	...	...	...	...

ATPS446-2 is a lower carbon version of TP 446-1 that has a lower tensile strength but improved ductility and fracture toughness.

BNew designation established in accordance with Practice E 527 and SAE J10886. Practice for Numbering Metals and Alloys (UNS).

CW hen intergranular corrosion testing is specified, the test will be Practices A 763, using samples prepared as agrred upon between the seller and the purchaser.

DF or smal diameter or thin walls, or both, tubing, where many drawing passes are required, a carbon maximum of 0.015% is necessary. Small outside diameter tubes are defined as those less than 0.500 in.[12.7mm] in average wall thickness (0.040 in.[1mm] in minimum wall thickness).

EPlate version of CA6NM.
FNickel plus copper.
GCarbon plus nitrogen = 0.025% max.

Number of Tubies in a Lot Heat Treated by the Continuous Process

Size of Tube	Size of Lot
2 in.[50.8mm] and over in outside diameter and 0.200 in. [5.1mm] and over in wall thickness	not more than 50 tubes
Less than 2 in. [50.8mm] but over 1 in.[25.4mm] in outside diameter or over 1 in. [25.4mm] in outside diameter and under 0.200 in.[5.1mm] in wall thickness	not more than 75 tubes
1 in. [25.4mm] or less in outside diameter	not more than 125 tubes

Tensile Requirements

NOTE - TP 329 (S32900), fomerly part of this specification has been transfered to A 789/A 789M and A 790/A 79M.

Grade and UNS Designation	Tensile strength, min, ksi[MPa]	Yield strength, min ksi[MPa]	ElongationA in 2 in or 50 mm, min,%
TP 405 S40500	30[415]	30[205]	20
... S40800	55[380]	30[205]	20
TP 410 S41000	60[415]	30[215]	20
TP 429, TP 430, and TP 430 Ti S429000, S43000, and S43036	60[415]	35[240]	20
TP 443 S44300	70[485]	40[275]	20
TP 446-1 S44600	70[485]	40[275]	18
TP 446-2 S44600	65[450]	40[275]	20
TP 409 S40900	55[380]	30[205]	20
TP 439 S43035	60[415]	30[205]	20
... S41500	115[795]	90[620]	15
TPXM-27 S44627	65[450]	40[275]	20
TPXM-33 S44626	68[470]	45[310]	20
18Cr-2Mo S44400	60[415]	40[275]	20
29-4 and 29-4-2 S44700 and S44800	80[550]	60[415]	20
26-3-3 S44600	85[585]	65[450]	20
25-4-4 S44635	90[620]	75[515]	20
... S44735	75[515]	60[415]	15

AFor longitudinal strip tests a deduction of 0.90% for TP 446-1 and S44735 and 1.00% for all other grades shall be
made from the basic minimum elongation for each 1/32-in. [0.8mm] decrease in wall thickness below 5/16 in.[8mm].
The following table gives the computed minimum values.

TABLE 3 Continued

Wall Thickness		Elongation in 2 in. or 50 mm, min,%
in.	mm	TP 446-1and S44735	S41500	All Other Grades
5/16[0.312]	8	18	15	20
9/32[0.281]	7.2	17	14	19
1/4[0.250]	6.4	16	14	18
7/32[0.219]	5.6	15	13	17
3/16[0.188]	4.8	14	12	16
5/32[0.156]	4	13	11	15
1/8[0.125]	3.2	13	11	14
3/32[0/094]	2.4	12	10	13
1/16[0/062]	1.6	11	9	12
0.062-0.035,excl	1.6-0.9	10	8	12
0.035-0.022, excl	0.9-0.6	10	8	11
0.022-0.015,incl	0.6-0.4	10	8	11

NOTE - The above table gives the computed minimum values for each 1/32-in. [0.8mm] decrease in wall thickness.
Where the wall thickness lies between two values shown above, the minimum elongation value shall be determined
by the following equation :

Grade	Equation
TP 446-1 and S44735	E = 28.8t + 9.00[E = 1.13t +9.00]
S41500	E = 24t + 7.5
All other grades	E = 32t + 10.00 [E = 1.25f + 10.00]

where :
E = elongation in 2in. or 50mm, %, and
t = actual thickness of specimen, in.[mm].
BCalculated elongation requirements shall be rounded to the nearest whole number.

Hardness Requirements

NOTE - TP329 (S32900), formerly part of this specification, has been transferred to A 789/A 789M and A790/A 790M.

Grade	UNS Designation	Brinell Hardness,max	Rockwell Hardness, B Scale, max
TP 405	S40500	207	95
...	S40800	207	95
TP 410	S41000	207	95
TP 429, TP 430, and TP 430 Ti	S42900,S43000, and S43036	190	90
TP 443	S44300	207	95
TP 446-1 and TP 446-2	S44600	207	95
TP 409	S40900	207	95
TP 439	S43055	190	90
...	S41500	295A	32
TP XM-33 and TPXM-27	S44626 and S44627	241	100
18CR-2Mo	S44400	217	95
29-4 and 29-4-2	S44700 and S44800	207	100
26-3-3	S44660	265	25A
25-4-4	S44635	270	27A
...	S44735	...	100

ARockwell hardness, C scale.

TABLE 5 Permissible Variations in Dimensions

Group	Size, Outside Diameter, in. [mm]	Permissible Variations in Outside Diameter, in.[mm]	Permissible Variations in Wall Thickness,C %	Permissble Variations in Cut Length, in.A[mm]		Thin Walled TubesB
Group	Size, Outside Diameter, in. [mm]	Permissible Variations in Outside Diameter, in.[mm]	Permissible Variations in Wall Thickness,C %	Over	Under	Thin Walled TubesB
1	Up to 1/2[12.7],excl	±0.005[0.13]	±15	1/8 [3]	0	...
2	1/2 to 1 1/2[12.7 to 38.1], excl	±0.005[0.13]	±10	1/8 [3]	0	less than 0.065[1.6mm] nominal
3	1 1/2 to 3 1/2[38.1 to 88.9],excl	±0.010[0.25]	±10	3/16 [5]	0	less than 0.095[2.4mm] nominal
4	3 1/2 to5 1/2[88.9 to 139.7],excl	±0.015[0.38]	±10	3/16 [5]	0	less than 0.150[3.8mm] nominal
5	5 1/2 to 8[139.7 to 203.2],incl	±0.030[0.76]	±10	3/16 [5]	0	less than 0.150[3.8mm] nominal

AThese tolerances apply to cut lengths up to and including 24 ft[7.3m].

For lengths over 24ft[7.3m] an additional over tolerance of 1/8 in.[3mm] for each 10 ft[3m]
or fraction thereof shall be permissible up to a maximum of 1/2 in.[13mm].
BOvality provisions of 12.2 apply.
CW hen tubes as ordered require wall thicknesses 3/4 in.[19mm] or over,
or an inside diameter 60% or less of the outside diameter,
a wider variation in wall thickness is required.
On such sizes a variation in wall thickness of 12.5% over or under will be permitted.
For tubes less than 1/2 in.[12.7mm] in inside diameter which cannot be successfully drawn over mandrel,
the wall thickness may vary ±15% from that specified.

Material Comparison Tables (ASTM →KS, JIS, DIN, BS, NBN, NF, UNI)

ASTMSTANDARD

UNS NO.

KOREA/JAPANES

GERMAN

BRITISH

BELGIAN

FRENCH

ITALIAN

KS/JIS Symbol

KS/JIS Numbe

Remarks

DIN Type

DIN Number

Materiral Number

Remarks

B.S Number

B.S Grade

Remarks

NBN Type

NBN Grade

Remarks

AFNOR Type

NF Number

UNI Type

UNI Number

Ramarks

A 268 Seamless and welded Ferritic Stainless Steel Tubing for General Service

Type 405

S40500

(3)

X7 CrAl

17440

1.4002

(3b)

Type 410

S41000

STS 405 TB / SUS 405 TB

D 3577 / G3463

X10 Cr13

17440

1.4006

(3b)

(3)

Product successfully added to your shopping cart

There are 64 items in your cart. There is 1 item in your cart.

Categories

Surplus stock of Steel Pipes & Tubes:

Specialist in:

Offering best price on:

Widest inventory of:

ASTM A268 / ASME SA268 / Seamless and Welded Ferritic Stainless Steel Tubing supplier & distributor in India

Steel pipe & tube ready inventory: