Conversion & Reference Chart

The American Piping Products conversion reference chart supplies helpful equations and comparison of units of measurement in a highly legible format. For a quick overview of the value of one yard into meters or the equivalent of one mile in kilometers, the metric reference chart outlines just the essentials. Formulas are provided for calculation of the weight per foot of pipes and tubes, computing the area of a cross section, and using Barlow’s Formula, ascertaining the bursting pressures of pipes and tubes. The formula for measuring carbon equivalent in alloy steel piping is also provided for quick reference.

Please note that the charts below are for reference only, simply to provide a rough estimate and overview. It is not encouraged that these reference materials be used in calculating the final data set in a steel pipe project. These conversion reference charts supply a quick and easy way for customers to get a general understanding of the steel pipe needed from American Piping Products.

(For Reference Only, Not for Design Purposes)

Metric Conversion Chart
1 Millimeter = 0.03937 Inches
1 Centimeter = 0.3937 Inches
1 Meter = 3.2808 Feet
1 Kilometer = 0.6214 Miles
1 Inch = 25.4 Millimeters
1 Foot = 0.3048 Meter
1 Yard = 0.914 Meter
1 Mile = 1.6093 Kilometers
1 Gram = 0.03527 Ounce
1 Kilogram = 2.2046 Pounds
1 Metric Ton = 2,204.6 Pounds
1 Short Ton = 907.184 Kilograms


Pipe and Tube Weight Per Foot Calculation
W = C (D – t) t
Where W = Weight lbs/ft (Kg/m)
C = 10.69 (0.0247) for Carbon Steel,
10.93 (0.0248) for Austenitic Stainless Steel
D = Outside Diameter, inch (mm)
t = Wall Thickness, inch (mm)
Cross – Sectional Area
A = 3.1416 t (D – t)
Where A = Sectional Area, inch2
D = Outside Diameter, inches
t = Wall Thickness, inches
Carbon Equivalent
CE = %C + (%Mn/6)+((%Cr + %Mo + %V/5)+((%Ni + %Cu/15)
C = Carbon Mo = Molybdenum
Mn = Manganese V = Vanadium
Cr = Chromium Ni = Nickel
Cu = Copper
Barlow’s Formula
P = (2 t s) / D
Barlow’s Formula is an easy method of predicting the bursting pressures of pipe and tube that are within actual test bursting pressures.
P = internal units pressure, psi
S = unit stress, psi
D = outside diameter of pipe, inches
t = wall thickness, inches