Minimum Bend Radius of Mineral Insulated RTDs
Mineral Insulated sensors can be bent in to many elaborate shapes. However, there is a minimum bend radius, which is 3 times the cable diameter.
The above image shows a 3mm diameter MI cable at its minimum bend. To calculate the minimum bend radius you simply multiply the diameter of the cable by 3, therefore the minimum inside radius of a bend for 3mm cable must be 3 x 3 = 9mm.
To calculate the circumference (18mm in fig 1) simply multiply the radius (9mm in fig 1) by 2. This is the minimum size of former you would have to use to form your MI cable in to shape.
Reference : sterlingsensors