Bundy Weld SAE J527 Brazed Steel Tubing

SAE J527 defines the standard specifications for double walled steel tubing (copper brazed).

12.7x1 Copper Brazed Double Wall Steel Tubes

Engineered Industries Limited offers double walled SAE J527 tubing with great quality, and very quick delivery.

We have plenty of stock of regular size tubing, and offer flexible packing and shipping options based on many year experience of ocean freight and airway cargo shipping.

Regular Size & Stock

Bundy tubes of the following table listed sizes are feasible to manufacturer; among them, thickness of 0.7mm and 1mm are available in stock most of the time or to be produced upon being ordered.

OD, mmWall Thickness, mm
Unit Weight (Theoretical), g/m

Custom Sizes

Bundy Tube Production Line

We are capable of fabricating Bundy tube sizes which are not regularly used. By combining one or more processes of cold drawing and annealing, Bundy tubes can be made to many other sizes to meet demands for special applications.

Click here to calculate the tube weight.

Dimensional Accuracy

ODTolerenceWall ThicknessTolerance
8-12.7±0.10 0.7-1±0.09
 >12.7 ±0.12 1-1.3±0.1


The tubes are made from low carbon steel strips (grade BHG2) which is manufactured by Bao Steel Group. The chemical compositions are as following:

Standard (max.,%)

Mechanical Properties

Tensile Strength42000psi (290MPa)
Yield Strength26100psi (180MPa)

Inside Surface Cleanliness:  0.16g/m2 , max

SAE J527 Brazed Steel Tubing

SAE J527 Brazed Steel Tubing

Bust Pressure

OD, mmWall Thickness, mm
Burst Pressure, MPa
 571.187.3104.2121.9140.5 160.0
 749.260.071.1 82.694.4106.7146.0
 1040.9 48.255.763.371.195.6
 12.731.737.3 43.048.854.773.0
Tube Gallaries , , ,