- Lewis Brass & Copper Company - https://lewisbrass.com -

# Weight Formulas

###### Burst Pressure Data

Burst pressures can be calculated by the following formula:
P=2T x S divided by O.D.

P = Burst Pressure PSI  |  T = Tubing Wall Thickness  |  O.D. = Outside Diameter of tubing
S
= Ultimate Strength of Material (32,000 PSI for copper / 47,000 PSI for brass)
Note:  Working PSI @ 6-safety factor of 6:1  |  Working PSI @ 8-safety factor of 8:1

###### Tube Length Information

A. Mill Lengths: Certain uniform lengths subject to established tolerances with short lengths included according to established agreement with customer.
B. Random Lengths: Run of mill lengths without any indicated preferred length, subject to customer approval.
C. Specific Lengths: Indicated uniform lengths, subject o established length tolerances (for example: 12′ – 0″, 9′ – 7″, or 0′ – 4 1/2″ os a specified length). Unless specified otherwise, tolerances are per ASTM B251.

###### Weight Per Foot

To determine Weight (WT) per linear foot of a seamless tube, when Outside Diameter (O.D.) is given:
A. Subtract Wall Thickness (T) from O.D., then multiply by wall thickness. (O.D. – T) x T = Z
B. Using figure obtained from above (Z), multiply by 11.5736 for brass or 12.1768 for copper.
For Brass: Z x 11.5736 = WT per linear foot of a brass seamless tube
For Copper:  Z x 12.1768 = WT per linear foot of a copper seamless tube

D = Diameter  |   D.A. = Density of Alloy  |  I.D. = Inside Diameter  |   O.D. = Outside Diameter
T = Wall Thickness or Thickness  |  WT = weight  | W = width

ROUND ROD
Square of D x 9.42 x DA = WT per lineal foot in pounds.

SQUARE BAR
Square of One Side x 12 x DA = WT per lineal foot in pounds.

HEXAGON ROD
Square of Distance Across Flats x 10.4 x DA = WT per lineal foot.

RECTANGULAR BAR
T x W x 12 x DA = WT per lineal foot in pounds.

ROUND TUBE
37.7 x DA x T x OD – T = WT per lineal foot in pounds.

SQUARE TUBE
1.27 X WT of a round tube of the same wall thickness, and of D equal to the distance across the flats of the square tube = WT per lineal foot.

SHEET
T x 144 x DA = WT per square foot in pounds.

STRIPS AND ROLLS
T x W x 12 x DA = WT per lineal foot in pounds.

CIRCLES
Square of D x T x 0.785 x DA = WT of a circle.

RINGS
O.D. + I.D. x O.D. – I.D. x T x 0.785 x D.A. = WT of ring in pounds.