Stainless Steel Tube & Pipe Dimension Tolerance

Outside diameter (OD), wall thickness and length are three basic parameters in the process of manufacture and distribution for stainless steel tube & pipe, and these parameters have been standardized.

Outer diameter and wall thickness are particularly important, they are not only the basic support for meeting the design requirements of various types of applications such as strength, stiffness and fluid delivery, but also have a decisive influence on the subsequent processing, therefore, standards for stainless steel tube & pipe diameter and wall thickness of the manufacturing accuracy (tolerance) should been standardized.

Stainless Steel Tube & Pipe Dimension Tolerance

European Standard

European stainless steel tube & pipe standards specify 4 classes outer diameter and wall thickness in percentage or absolute value on the basis of nominal dimension.

Generally, larger diameter or heavy wall thickness stainless steel pipe use percentage, small diameter or thin wall thickness stainless steel tube use absolute value.

StandardManufacturing Process & TypeOuter Diameter ToleranceWall Thickness ToleranceOthers
OD (mm)Class
EN10216-5Hot finished seamless tube219.1~610D1+22.5%t,-15%tt/D≤0.05
T1t/D≤0.09
T2t/D>0.09
30~219.1D2T1 
T2 
Cold finished seamless tubes≤219.1D3T3 
D4T4agreement
EN10297-2Hot finished seamless tube D1T1 
D2T2agreement
Cold finished seamless tubes D3T3 
D4T4agreement
EN10217-7Welded tubes>168.3D2T3 
≤168.3D3T3 
D4T3agreement
EN10296-2Welded tubes>168.3D2T3 
≤168.3D3T3 
≤114.3D4T3agreement
EN10312Welded tubesSeries 1D4T3t=0.6~2 mm
Series 2D3 – D4T3 – T4t=1~3 mm

From D1 to D4 class for outer diameter, and T1 to T4 for wall thickness tolerance comply to DIN EN ISO 1127 standard, stainless steel tubes – Dimensions, tolerances and conventional masses per unit length.

Outside diameterWall Thickness
ClassToleranceClassTolerance
D1±1.5%, or ±0.75 mm min.T1±15%, or ±0.6 mm min.
D2±1.0%, or ±0.5 mm min.T2±12.5%, or ±0.4 mm min.
D3±0.75%, or. ±0.3 mm min.T3±10%, or ±0.2 mm min.
D4±0.50%, or ±0.1 mm min.T4±7.5%, or ±0.15 mm min.
T5 +/- 5.0 %, or +/- 0.10 mm min.

America standard

America standard has two standard rules to specify outside diameter and thickness, ASTM A999 / A999M and A1016 / A1016M.

A999 includes A312 / A12M, A358 / A358M, A376 / A376M, A409 / A409M, A778, A790 / A790M, A813 / A813M, A814 / A814M, A928 / A928M etc named pipe in stainless steel materials standards.

A1016 includes A213 / A213M, A249 / A249M, A268 / A268M, A269, A270, A688 / A688M, A789 / A789M, A803 / A803M etc named tube in stainless steel materials standards.

But A511 for seamless stainless steel mechanical tubing and A554 welded stainless steel mechanical tubing not conform to above standards, they have separate outside diameter and thickness tolerances.

StandardManufacturing & delivery conditionOutside Diameter
OD / mm
OD tolerance mmThickness
T / mm
T tolerance mm
MinimumAverage
ASTM A1016 / A1016MHot drawn seamless tubes<=100+0.4, -0.8<=2.4+0.4t, 0 
100 – 200+0.4, -1.22.4 – 3.8+0.35t, 0 
200 – 225+0.4, -1.63.8 – 4.6+0.33t, 0 
  >=4.6+0.28t, 0 
Cold drawn seamless tubes<25+0.1, -0.11 +0.20t, 0+/-0.10t
25 – 40
40 – 50+/-0.2 +0.22t, 0+/-0.10t
50 – 65+/-0.25
65 – 75+/-0.3
75 – 100+/-0.38
100 – 200+/-0.38, -0.04
200 – 250+/-0.38, -1.14
Welded tubes40 – 50+/-0.2 +0.18t, 0+/-0.10t
50 – 65+/-0.25
65 – 75+/-0.3
75 – 100+/-0.38
100 – 200+/-0.38, -0.04
200 – 250+/-0.38, -1.14
ASTM A999 / MSeamless tubes and welded tubes<48.3+0.4, -0.8 -0.125t
ASTM A312 / MSeamless tubes and welded tubes48.3-114.3+/-0.8OD=10.3-73+0.20 t, -125t
168.3-219.1+1.6, -0.8t/OD<=5% OD=88.9-457.2+0.225 t, -125t
219.1-457.2+2.4, -0.8t/OD>5% OD=88.9-457.2  +0.15 t, -125t
Welded tubes508-660+3.2, -0.8OD>=508+0.175 t,-0.125 t
711-864+4.0, -0.8t/OD<=5%, OD>=508+0.225 t,-0.125 t
Seamless tubes914-1209+4.8, -0.8t/OD>5%, OD>=508+0.15 t, -125t
ASTM A409 / MWelded tubes +/-0.2%T<4.8 
+/-0.4%t>=4.8 
ASTM A358 / MWelded tubes +/-0.50%   
ASTM A511Seamless tubing<=12.7+/-0.1  +/-0.15t
12.7-38.1+/-0.2  +/-0.10t
38.1-88.9+/-0.3
88.9-139.7+/-0.4
139.7-203.1+/-0.8
203.1-220+/-1.1
220-325+/-1.6

China standard and comparison

China has more quantity standards compared to European standards, but less than american standards, SS tube and pipe standards are similar with EU standards in system, and absorb favorable experience in USA specifications.

Dimension, mm Outside diameter tolerance, mm
EN10216-5 ASTM A1016/M GB 13296 GB/T14976   EN10217-7 ASTM A999/M GB/T 12771
25 x 2 +/-(0.20-0.30) +0.10, -0.11 +0.15, -0.22 +/-(0.20-0.30) +/-(0.20-0.30) +0.40, -0.80 +/-(0.20-0.30)
76 x 3.6 +/-(0.38-0.57) +/-0.38 +/-0.57 +/-(0.76-0.95) +/-(0.40-0.50) +/-0.30 +/-(0.40-0.50)
219.1 x 6 +/-(1.1-1.65) +0.38, -1.14 +/-1.65(cold), +/-2.2(hot) +(2.2-3.3) +(1.65-2.20) +1.6, -0.8 +(1.65-2.20)
610 x 6 +/-9.15       +/-6.10 +3.2, -0.8 +/-(3.05-4.57) as welded, +/-(3.65-4.2) heat solution
Dimension, mm Thickness, mm
EN10297 ASTM A312/M GB13296 GB/T14976 EN10296 ASTM A312 GB/T12771
25 x 2 +/-(0.15-0.2) +/-0.2 +/-0.20 (+0.25, -0.20) – +/-0.28 +/-0.2 +0.4, -0.25 +/-0.20
76 x 3.6 +/-(0.27-0.36) +/-0.36 +/-0.40 +/-0.45-(+0.54 , -0.45) +/-0.30 +0.79, -0.45 +/-0.30
219.1 x 6 +/-(0.45-0.60) +/-0.60 +1.32, 0(cold), +1.68, 0(hot) +/-0.75-(+0.90, -0.75) +/-0.60 +1.32, -0.75 +/-0.60
610 x 6 +/-1.40, -0.90       +/-0.60 +(1.05-1.38), -0.75 +/-0.60

Out of roundness and thickness uniformity

Out of roundness and thickness uniformity are tube & pipe on the same cross-section of the outer diameter and wall thickness tolerances, roundness or ovality is difference between the maximum and minimum dimensions of outside diameter, is carefully measured the high and low points at any one section of the tube & pipe.

tube & pipe ovality

Concentricity or eccentricity refer to tube & pipe wall thickness variations, if need a high precision in tube tolerance, or fit into other tube or parts, which need a good concentricity.