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B337 existed for the specification of tubes outside of the applications at the focus of ASTM B338 however has now been withdrawn in favor of two separate standards (ASTM B861 and ASTM B862) which treat the separate forms (Seamless / Welded) in differing ways.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
Element Grade 1 Grade 2 Grade 3 Grade 7 Grade 9 Grade 11 Grade 12
Nitrogen, max 0.03 0.03 0.05 0.03 0.03 0.03 0.03
Carbon, max 0.08 0.08 0.08 0.08 0.08 0.08 0.08
Hydrogen,B,C max 0.015 0.015 0.015 0.015 0.015 0.015 0.015
Iron, max 0.2 0.3 0.3 0.3 0.25 0.2 0.3
Oxygen, max 0.18 0.25 0.35 0.25 0.15 0.18 0.25
Aluminum 2.5±3.5
Vanadium 2.0±3.0
Tin
Ruthenium
Palladium 0.12±0.25 0.12±0.25
Cobalt
Molybdenum 0.2±0.4
Chromium
Nickel 0.6±0.9
Niobium
Zirconium
Silicon
Residuals,D,E,F Max each 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Residuals,D,E,F Max total 0.4 0.4 0.4 0.4 0.4 0.4 0.4
TitaniumG balance balance balance balance balance balance balance
Element Grade 13 Grade 14 Grade 15 Grade 16 Grade 17 Grade 18 Grade 26
Nitrogen, max 0.03 0.03 0.05 0.03 0.03 0.03 0.03
Carbon, max 0.08 0.08 0.08 0.08 0.08 0.08 0.08
Hydrogen,B,C max 0.015 0.015 0.015 0.015 0.015 0.015 0.015
Iron, max 0.2 0.3 0.3 0.3 0.2 0.25 0.3
Oxygen, max 0.1 0.15 0.25 0.25 0.18 0.15 0.25
Aluminum 2.5±3.5
Vanadium 2.0±3.0
Tin
Ruthenium 0.04±0.06 0.04±0.06 0.04±0.06 0.08±0.14
Palladium 0.04±0.08 0.04±0.08 0.04±0.08
Cobalt
Molybdenum
Chromium
Nickel 0.4±0.6 0.4±0.6 0.4±0.6
Niobium
Zirconium
Silicon
Residuals,D,E,F max each 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Residuals,D,E,F max total 0.4 0.4 0.4 0.4 0.4 0.4 0.4
TitaniumG balance balance balance balance balance balance balance
Element Grade 27 Grade 28 Grade 30 Grade 31 Grade 33 Grade 34 Grade 35 Grade 36
Nitrogen, max 0.03 0.03 0.03 0.05 0.03 0.05 0.05 0.03
Carbon, max 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.04
Hydrogen,B,C max 0.015 0.015 0.015 0.015 0.015 0.015 0.015 0.0035
Iron, max or range 0.2 0.25 0.3 0.3 0.3 0.3 0.20-0.80 0.03
Oxygen, max 0.18 0.15 0.25 0.35 0.25 0.35 0.25 0.16
Aluminum 2.5±3.5 4.0-5.0
Vanadium 2.0±3.0 1.1-2.1
Tin
Ruthenium 0.08±0.14 0.08±0.14 0.02-0.04 0.02-0.04
Palladium 0.04±0.08 0.04±0.08 0.01-0.02 0.01-0.02
Cobalt 0.20±0.80 0.20±0.80
Molybdenum 1.5-2.5
Chromium 0.1-0.2 0.1-0.2
Nickel 0.35-0.55 0.35-0.55
Niobium 42.0±47.0
Zirconium
Silicon 0.20-0.40
Residuals,D,E,F max each 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Residuals,D,E,F max total 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4
TitaniumG balance balance balance balance Remainder Remainder Remainder Remainder

Mechanical Properties

Grade Tensile Strength, min Yield Strength, 0,2% Offset Elongation
in 2in
or 50mm, min %
ksi MPa min max
ksi MPa ksi MPa
1A 35 240 25 170 45 310 24
2A 50 345 40 275 65 450 20
3A 65 450 55 380 80 550 18
7A 50 345 40 275 65 450 20
9B 125 860 105 725 10
9A 90 620 70 483 15C
11A 35 240 25 170 45 310 24
12A 70 483 50 345 18C
13A 40 275 25 170 24
14A 60 410 40 275 20
15A 70 483 55 380 18
16A 50 345 40 275 65 450 20
17A 35 240 25 170 45 310 24
18B 125 860 105 725 10
18A 90 620 70 483 15C
26 50 345 40 275 65 450 20
27 35 240 25 170 45 310 24
28 90 620 70 483 15
30 50 345 40 275 65 450 20
31 65 450 55 380 80 550 18
33 50 345 40 275 65 450 20
34 65 450 55 380 80 550 18
35 130 895 120 828 5
36 65 450 60 410 95 655 10

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)A Permissible 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), excl 60.010 (60.254) +/-10

Straightness

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