
Our Bal Conn® electrical contact is the component of choice for designers who need to make reliable, consistent connections in active medical implantables for cardiac rhythm management and neuromodulation. For more than 20 years, it has been improving device performance, supporting emerging therapies, and making smaller, more functional devices possible. Its uncompromising conductivity and compact design make it ideal for use in devices with high connection counts.
Bal Conn Electrical Contact Construction
Consisting of a housing made from medical-grade alloys and a Bal Spring® canted coil spring, the Bal Conn is precision-built to help device designers connect with confidence. Its spring coils ensure ultra-reliable multi-point electrical contact with superior resistance to fatigue.

Bal Conn housings are typically cylindrical, but their geometry can be customized to incorporate features that aid in retention and simplify assembly processes. The Bal Conn is also available in a form factor that combines proven Bal Spring technology with a thinner housing configuration to lower electrical impedance, further reduce axial pitch, and conserve valuable header space.
Bal Conn Electrical Contact Sizes
The Bal Conn electrical contact plays a big role in the consistent, reliable operation of active medical implantables. But it keeps a very low profile, managing more power in less space than any other leading contact technology. With our advanced manufacturing processes, we can produce these contacts with inside diameters ranging from 0.028 in. (.7 mm) to .197 in. (5 mm).

Bal Conn Electrical Contact Function
The Bal Conn® enables transmission of power from the battery and electronics to the lead in implantable medical devices. Typically, multiple Bal Conn electrical contacts are arranged in a serial configuration as part of the interconnect system in a device header, or in an interconnect for a lead segment that helps reduce patient risk. The contact’s canted coil spring element aligns with an electrode on the device lead, creating a reliable connection with very low contact resistance (<100 mΩ).

Bal Conn Electrical Contact Configurations
Since every Bal Conn electrical contact is designed to meet the unique requirements of your application, we don’t stock a “standard” size and type. But we do maintain a database of designs that meet current standards for IS-1, IS-4, DF-4, and VAD, as well as common neuromodulation requirements. These can serve as a baseline for accelerated customization.

Bal Conn for Neuromodulation
Feature: Compact size
Benefit: Allows for increased number of connections in series
Service type: Bi-directional
Lead diameter (mm): 1.30
Breakout force max (N): 0.70 to 1.20
Running force (N): 0.07 to 0.40
Housing materials: MP35N®, 316L, medical grade titanium, platinum iridium
Spring material: Platinum iridium
Static dry contact resistance (mΩ): 40 to 600 (nominal), +/- 15 to +/- 200 (tolerance)

Bal Conn for IS-1 Cardiac Applications
Feature: Axial spring design
Benefit: Enables low contact resistance without noble metals
Service type: Bi-directional
Lead diameter (mm): 2.67
Breakout force max (N): 3.10
Running force (N): 0.50 to 0.90
Housing materials: 316L
Spring material: MP35N®
Static dry contact resistance (mΩ): 100 (nominal), +/- 60 (tolerance)

Bal Conn for IS-4/DF-4/VAD Cardiac Applications
Feature: More points of contact
Benefit: Reduced contact resistance
Service type: Bi-directional
Lead diameter (mm): 3.20
Breakout force max (N): 2.70
Running force (N): 0.25 to 0.75
Housing materials: MP35N®, platinum iridium
Spring material: MP35N®, platinum iridium
Static dry contact resistance (mΩ): 30 to 80 (nominal), +/- 20 to +/- 50 (tolerance)

Bal Conn for IS-4/DF-4
Feature: Axial spring design
Benefit: Low contact resistance
Service type: Uni-directional
Lead diameter (mm): 3.20
Breakout force max (N): 2.70
Running force (N): 0.50 to 1.00
Housing materials: MP35N®
Spring material: MP35N®
Static dry contact resistance (mΩ): 80 (nominal), +/- 50 (tolerance)
This data is presented for comparative purposes only, and it represents the performance of our contact under specific design parameters. Results may vary depending on application requirements and other factors.
Bal Conn Electrical Contact Materials
Our Bal Conn electrical contact is available in a range of implantable-grade, biocompatible housing and spring materials.
Housing Materials Include:
- MP35N®
- MEDICAL GRADE TITANIUM
- STAINLESS STEEL (302, 316, 316L)
- PLATINUM IRIDIUM
Spring Energizer Materials Include:
- MP35N®
- PLATINUM IRIDIUM
Bal Conn Electrical Contact Spring Force
At the heart of the ultra-reliable Bal Conn electrical contact is our proven Bal Spring® canted coil spring technology. Our spring exerts a near-constant force across the working deflection range, and its forces remain consistent. The spring resists compression set, and its individual coils compensate for misalignment, tolerance variations, and mating surface irregularities. Its multiple coils also provide contact redundancy.
