ASTM B338

The standard ASTM B338 is the industry standard for the production of titanium tubes for use in applications including: heat exchangers, condensers and evaporators. It is the most commonly used standard worldwide when specifying titanium tubing. The standard is used to specify titanium tubes irrespective of form (Seamless Tubing or Welded Tubing). A previously available separate standard ASTM B337 existed for the specification of tubes outside of the applications at the focus of ASTM B338 however has now been withdrawn in favor of two separate standards (ASTM B861 and ASTM B862) which treat the separate forms (Seamless / Welded) in differing ways.

Chemical Composition

Grade 1 to 12Grade 13 to 26Grade 27 to 36
ElementGrade 1Grade 2Grade 3Grade 7Grade 9Grade 11Grade 12
Nitrogen, max0.030.030.050.030.030.030.03
Carbon, max0.080.080.080.080.080.080.08
Hydrogen,B,C max0.0150.0150.0150.0150.0150.0150.015
Iron, max0.20.30.30.30.250.20.3
Oxygen, max0.180.250.350.250.150.180.25
Aluminum2.5±3.5
Vanadium2.0±3.0
Tin
Ruthenium
Palladium0.12±0.250.12±0.25
Cobalt
Molybdenum0.2±0.4
Chromium
Nickel0.6±0.9
Niobium
Zirconium
Silicon
Residuals,D,E,F Max each0.10.10.10.10.10.10.1
Residuals,D,E,F Max total0.40.40.40.40.40.40.4
TitaniumGbalancebalancebalancebalancebalancebalancebalance
ElementGrade 13Grade 14Grade 15Grade 16Grade 17Grade 18Grade 26
Nitrogen, max0.030.030.050.030.030.030.03
Carbon, max0.080.080.080.080.080.080.08
Hydrogen,B,C max0.0150.0150.0150.0150.0150.0150.015
Iron, max0.20.30.30.30.20.250.3
Oxygen, max0.10.150.250.250.180.150.25
Aluminum2.5±3.5
Vanadium2.0±3.0
Tin
Ruthenium0.04±0.060.04±0.060.04±0.060.08±0.14
Palladium0.04±0.080.04±0.080.04±0.08
Cobalt
Molybdenum
Chromium
Nickel0.4±0.60.4±0.60.4±0.6
Niobium
Zirconium
Silicon
Residuals,D,E,F max each0.10.10.10.10.10.10.1
Residuals,D,E,F max total0.40.40.40.40.40.40.4
TitaniumGbalancebalancebalancebalancebalancebalancebalance
ElementGrade 27Grade 28Grade 30Grade 31Grade 33Grade 34Grade 35Grade 36
Nitrogen, max0.030.030.030.050.030.050.050.03
Carbon, max0.080.080.080.080.080.080.080.04
Hydrogen,B,C max0.0150.0150.0150.0150.0150.0150.0150.0035
Iron, max or range0.20.250.30.30.30.30.20-0.800.03
Oxygen, max0.180.150.250.350.250.350.250.16
Aluminum2.5±3.54.0-5.0
Vanadium2.0±3.01.1-2.1
Tin
Ruthenium0.08±0.140.08±0.140.02-0.040.02-0.04
Palladium0.04±0.080.04±0.080.01-0.020.01-0.02
Cobalt0.20±0.800.20±0.80
Molybdenum1.5-2.5
Chromium0.1-0.20.1-0.2
Nickel0.35-0.550.35-0.55
Niobium42.0±47.0
Zirconium
Silicon0.20-0.40
Residuals,D,E,F max each0.10.10.10.10.10.10.10.1
Residuals,D,E,F max total0.40.40.40.40.40.40.40.4
TitaniumGbalancebalancebalancebalanceRemainderRemainderRemainderRemainder

Mechanical Properties

GradeTensile Strength, minYield Strength, 0,2% OffsetElongation
in 2in
or 50mm, min %
ksiMPaminmax
ksiMPaksiMPa
1A35240251704531024
2A50345402756545020
3A65450553808055018
7A50345402756545020
9B12586010572510
9A906207048315C
11A35240251704531024
12A704835034518C
13A402752517024
14A604104027520
15A704835538018
16A50345402756545020
17A35240251704531024
18B12586010572510
18A906207048315C
2650345402756545020
2735240251704531024
28906207048315
3050345402756545020
3165450553808055018
3350345402756545020
3465450553808055018
351308951208285
3665450604109565510

Dimensions Tolerances

Length Tolerances

For tube ordered in cut lengths the tube length should be no shorter than that size. For tubes up 7.3m in length then the tolerance should be no more than 3.2mm. For lengths over 7.3m then the permitted tolerances are a factor of length and based on 3.2mm for every 3.2m of length.

Variations in Outside Diameter

Outside Diameter, in. (mm)Diameter Tolerance, in. (mm)APermissible Variations B in Wall Thickness, t, %
Under 1 (25.4), excl+/-0.004 (+/-0.102)+/-10
1 to 11/2 (25.4 to 38.1), excl+/-0.005 (+/-0.127)+/-10
11/2 to 2 (38.1 to 50.8), excl+/-0.006 (+/-0.152)+/-10
2 to 21/2 (50.8 to 63.5), excl+/-0.007 (+/-0.178)+/-10
21/2 to 31/2 (63.5 to 88.9), excl60.010 (60.254)+/-10

Straightness

Length, ft (m)Maximum Curvature Depth of Arc
Over 3 to 6 (0.91 to 1.83), incl1/8 in. (3.2 mm)
Over 6 to 8 (1.83 to 2.44), incl3/16 in. (4.8 mm)
Over 8 to 10 (2.44 to 3.05), incl1/4 in. (6.4 mm)
Over 10 (3.05)1/4 in./any 10 ft (2.1 mm/m)