For our swaging product line, customers often ask for recommendations on materials and sizes of marker bands. Platinum-Iridium bands are the most popular material used for radiopaque applications. Our equipment is also capable of swaging gold, stainless steel and other materials.
For size recommendation we have found that having a band ID 0.001”-0.002” larger than the OD of in tubing is an appropriate size. (0.0015” difference is our recommendation). The reason this dimensional specification is important is that when the difference between the marker band ID and catheter OD is too great the finished product will often show visible lines and buckling of the band. The material of the marker band should be close enough to the tubing so that the forces from pre-swage or swaging processes does not cause these surface deformations. Proper sizing of the marker band is a critical input parameter to yield swaged bands with a smooth finish.
Sizing of marker bands is also critical for positioning of the marker band. The bands should slide smoothly on the surface of the tube when moved by hand. Tolerance of the tubing is critical as bumps can cause the band to catch when trying to position the band. A general rule is that if an operator can smoothly position the band by hand, then an automated machine should be able to perform the same task with high yields.