When it comes to the manufacturing and quality assurance of carbon and alloy steel pipes, ASTM A530 / A530M serves as the general specification that governs the dimensional tolerances, surface finish, straightness, and other critical requirements. Whether used for structural purposes, mechanical systems, or pressure piping, steel pipes must meet precise standards to ensure performance, safety, and compatibility.
This blog provides a detailed look into the tolerance tables outlined in ASTM A530 / A530M, including ovality, wall thickness, length, and straightness limits. Understanding these tolerances not only helps in selecting the right product but also in ensuring compliance during inspection and delivery.
Let’s dive into the key tolerance specifications and what they mean for steel pipe selection and application.
Union Steel Industry Co., Ltd is professional steel pipes manufacturer, for more details, please contact:sales@union-steels.com
Standard Cross-Section and Weight Tolerances of ASTM A530 / A530M Steel Pipe
|
NPS
|
Outside Diameter (OD)¹
|
Wall Thickness (t)²
|
Weight ³
|
|
Under
|
Over
|
Under
|
Over
|
Under
|
Over
|
|
in
|
mm
|
in
|
mm
|
%
|
%
|
%
|
%
|
|
⅛ – 1½
|
0.031
|
0.8
|
0.015
|
0.4
|
12.5
|
20
|
3.5
|
10
|
|
> 1½ – 4
|
0.031
|
0.8
|
0.031
|
0.8
|
12.5
|
20
|
3.5
|
10
|
|
> 4 – 8
|
0.031
|
0.8
|
0.062
|
1.6
|
12.5
|
22.5
|
3.5
|
10
|
|
> 8 – 12
|
0.031
|
0.8
|
0.093
|
2.4
|
12.5
|
22.5
|
3.5
|
10
|
|
> 12 – 18
|
0.031
|
0.8
|
0.093
|
2.4
|
12.5
|
22.5
|
5
|
10
|
|
> 18 – 26
|
0.031
|
0.8
|
0.125
|
3.2
|
12.5
|
22.5
|
5
|
10
|
|
> 26 – 34
|
0.031
|
0.8
|
0.156
|
4.0
|
12.5
|
22.5
|
5
|
10
|
|
> 34 – 48
|
0.031
|
0.8
|
0.187
|
4.8
|
12.5
|
22.5
|
5
|
10
|
Notes:
Ovality Tolerance: Applicable to all pipes except thin-wall types (i.e., where wall thickness t > 3% of the outside diameter OD).
Minimum Wall Thickness: The minimum wall thickness shall be 87.5% of the nominal wall thickness (t × 0.875). This requirement does not apply if filler metal is used.
Weight Calculation for Non-Standard Pipes:
In pounds per foot: W (lb/ft) = 10.68 × (OD – t) × t
In kilograms per meter: W (kg/m) = 0.02466 × (OD – t)
Standard Cut Lengths:
Ordering Options:
Random Lengths: Typically range from 15 to 24 feet. Shorter lengths may be supplied by mutual agreement with the purchaser.
Specified Lengths: Pipes are cut to exact lengths as requested, with specified end finishing.
Length Tolerances:
No pipe shall be shorter than the specified length.
No pipe shall exceed the specified length by more than ¼ inch (6 mm).
Stricter tolerances may be applied, particularly for beveled-end pipes.
Straightness Requirement:
All finished pipes must be reasonably straight. For metal-arc welded pipes, the maximum allowed deviation from straightness is ⅛ inch (3.2 mm) over a 10-foot (3 m) length.
English
Español
Tel : +86-18565811709
Email : 
News
