CONTRACT MANUFACTURING

 

PREFERRED TUBE BENDING & HELICAL COILING GUIDELINES

The following would be considered standard manufacturing criteria for contract manufacturing tube coiling projects.

 

Tube Coiling Considerations:

• Standard metal tubing size range from 1/8" O.D. to 1.25" O.D. For detail tube sizes in stock, please check this link

• Tolerances kept to +/-.030". Large parts will be measured in a constrained condition.

• Coil diameter minimum is best kept to 10 times tubing diameter. (Minimize tube flattening and keeps tooling simple.)

• Stainless Steel tube design pressure rate can be found from here

 

 

Tube Bending Considerations:

• CLR- Center Line Radius. Typical CLR is 3x the OD of the tube without mandrels. It is possible to bend on a 1 or 2xD bend, but not without more complex tooling. Tooling costs also increase when comparing a plug mandrel to 3-ball mandrel & wiper die. The tighter the radius, the more tooling required and the more expensive the part.

• Use the same CLR for all bends unless prohibited by design restraints.

• Straight between bends. Allow 3x the OD of straight for clamping between bends and from the edge of the tube. This reduces the overall cost of part by reducing additional trim operations and increasing the bend rate. Bends closer than 3xD require compound tooling increasing tooling cost and reducing bend rates.

 

Tolerances:

• The tighter the tolerance, the greater the cost. Don' t pay for something you don' t need.

• Where possible open all tolerances and deviate from engineering block tolerances when appropriate.

 

Have more questions on how to coil tubing? Contact us to discuss your project.