Inner Core vs. No Core

Drain cables come in one of two configurations: inner-core or no-core. The advantages of no-core cable are less weight and greater flexibility than the same cable with an inner-core. The disadvantage comes from having nothing inside the cable for it to grip down on when the cable encounters a blockage; thus no-core cable provides less overall drain cleaning power.

Spartan’s inner-core floats freely inside the outer cable for ¾ and 5/8 inch snakes, to ensure that they are flexible enough to shoot through most drain sizes. For small and mid-sized cables, where flexibility is a little less important due to the smaller
diameter of the snake, one end of the inner core is fastened to the outer wire to prevent the inner core from sliding out of the outer wire. Our most popular .55 and .66 Magnum lines fasten the inner core to both cables ends, which helps it to
provide Magnum’s speedy torque times.

Typically, drain snakes for the smallest lines and the smallest drain cleaning machinery – for sinks and tubs – are almost always no-core cables. This is to ensure that the cable can effectively maneuver through small diameter traps and sweeps commonly found in household bathrooms and kitchens. Thus, for small lines, flexibility is often the key, which means no-core cable.

In medium size lines and up, those lines 2 inches or greater in diameter, the drain cleaner can choose between inner-core cable and no-core cable. No-core cable will be lighter weight than inner-core cable, and will be more flexible. However innercore cables provide an important benefit for the increased weight and loss of flexibility. You see, drain cables are fundamentally long springs that, when they meet an obstacle in a drain line, swiftly compress or torque down on themselves,transforming this previously flexible drain snake into a stiffened rod. The actual breaking up or driving through a blockage comes by repetitively flexing the drain cables direct into the clog and allowing it to torque up into this stiff rod. Innercore cable substantially quickens that torque into the clog by giving the outer cable something to squeeze down against. So for a little more weight and a little less flexibility, the drain cleaner is able to clear drains more quickly using inner-core cable than he or she could using no-core cable.

In lines of 2 or 3 inches, the choice of speed over weight and flexibility is a personal choice. But in the very longest lengths of cables in the largest diameter snakes, the weight differential can be very dramatic – 40% in these instances. So for the Model 2001 and the Model 1065 in cable lengths 100 feet and above, most Spartan customers choose no-core cables due to the added weight of inner core. Of course these customers can save weight and improve torque times by switching to Spartan’s exclusive Magnum™ line of cable, which torques up more quickly than standard cable while coming in at 1/3 less weight.