Tube bending may be required as a form of metal forming for tubular installation. Here are some of our top tips for ensuring a safe and correct bending procedure.
Tube Bending Tips
Always bend tube prior to insertion in connectors and ensure adequate length of straight tube to fully enter the connector abutment.
These lengths should be added to the radius of tube bend as recommended by the tube bender manufacturer.
When using tube benders always follow the manufacturers instructions for the make of tube bender in use at the time.
The radius of the bend is as recommended by the tube bender manufacturer.
Recommended Bend Lengths
The minimum straight length of tube before a bend is shown in the table below:
| Tube OD (inches) | 1/4″ | 5/6″ | 3/8″ | 1/2″ | 5/8″ | 3/4″ | 1″ |
|---|---|---|---|---|---|---|---|
| Tube OD (mm) | 6mm | 8mm | 10mm | 12mm | 16mm | 20mm | 25mm |
| Straight Length (inches) | 0.82″ | 0.88″ | 0.94″ | 1.19″ | 1.25″ | 1.25″ | 1.5″ |
| Straight Length (mm) | 20.8mm | 22.3mm | 23.8mm | 30.2mm | 31.7mm | 31.7mm | 39.3mm |
Tube Bending Problems
The bending of tube adjacent to compression connectors requires care as sealing problems can result. These can be caused by:
a. linear score marks created by worn bending tool formers.
b. tube may be deformed on section.
c.over/under bent tube causing misalignment and excessive stresses.
d. insufficient straight length of tube before a bend.
When Using Tube
- Do not crush tube in vice jaws, use either soft jaws or aluminium tube jaws
- Do not force tube that is not round into tube or pipe fittings
- Do not use damaged tube, cut it back to where the tube is not damaged before use
Helpful articles:
- What is tube bending? WISEGEEK
- How To Achieve The Perfect Bend – The Fabricator
*Information produced from Waverley Brownall official training manual: Installation and Maintenance of Small Bore Pipework for Duoloc single ferrule fittings. Not to be reproduced, re-written or copied to other websites under the copyright material act.