Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
CAN/CSA C50068-99 (R2016): Technical Requirements for Wrought Aluminium and Aluminium Alloy Extruded Electrical Products
Scope, Material Properties, and Compliance Criteria for Conductor-Grade Aluminium Extrusions
CAN/CSA C50068-99 (R2016) is a Canadian national standard that specifies the characteristics, testing requirements, and acceptance criteria for wrought aluminium and aluminium alloy extruded bar, rod, tube, profiles, and wire intended for electrical purposes. Originally published in 1999 and reaffirmed without technical change in 2016, the standard remains a key reference for manufacturers, specifiers, and regulatory bodies across Canada’s electrical power and distribution sectors. It aligns closely with international practices while providing specific provisions tailored to Canadian climatic and installation conditions.
Scope and Application
The standard applies to extruded products manufactured from aluminium and aluminium alloys that are used as current-carrying components in electrical equipment. Typical applications include:
- Bus bars and bus bar profiles in switchgear and panelboards
- Connector bars, terminals, and lugs
- Conductor rails and electrification tracks
- Grounding and bonding conductors
- Wire for overhead service drops and secondary distribution
Excluded from the scope are aluminium-clad steel products, stranded conductors for overhead transmission lines (covered by other CSA standards such as C49.1), and products intended for structural or architectural applications where electrical conductivity is not a primary requirement.
Note: Although reaffirmed in 2016, users should verify with CSA Group whether any amendments or newer editions (e.g., C50068-19) have been published, as the standard may be subject to periodic revision.
Technical Requirements
Material Composition and Alloy Designations
CAN/CSA C50068-99 (R2016) recognizes specific wrought aluminium alloys that have been proven to provide the necessary balance of electrical conductivity, mechanical strength, and corrosion resistance. The standard references the following alloy families:
| Alloy Designation | Temper | Minimum Conductivity (% IACS) | Typical Application |
|---|---|---|---|
| 1350 (EC Grade) | O, H12, H14, H16, H18 | 61.0 | General-purpose bus bar, wire |
| 6101 | T6, T61, T63, T64 | 58.0 | High-strength bus bar, switchgear components |
| 6061 | T6 | 43.0 | Structural electrical supports, enclosures |
| 6063 | T5, T6 | 53.0 | Extruded profiles for conductor rails |
| 6201 | T81 | 52.5 | High-strength overhead conductor wire |
All chemical compositions must comply with the limits set forth in ANSI H35.1/H35.1(M) as adopted by CSA. Impurity limits for iron, silicon, copper, and other elements are strictly controlled to maintain electrical performance.
Mechanical Properties
The standard specifies minimum tensile strength, yield strength (0.2% offset), and elongation values for each alloy-temper combination. These values depend on the product form (e.g., bar, tube, wire) and cross-sectional dimensions. For example:
- Alloy 1350-H14: Minimum tensile strength 95 MPa (14 ksi), minimum elongation 10% (in 50 mm).
- Alloy 6101-T6: Minimum tensile strength 200 MPa (29 ksi), minimum yield strength 170 MPa (25 ksi), minimum elongation 10%.
For wire products, the standard adopts a bend test and a wrap test to verify ductility and coating adhesion (if applicable). Products must not exhibit cracking or delamination.
Electrical Conductivity
Conductivity is the paramount requirement. All products must achieve the minimum conductivity values listed in the alloy table above, measured at 20°C on a fully annealed sample or on the finished product as per ASTM B193. The standard allows a tolerance of –0.5% IACS for individual test results provided the average of five consecutive samples meets the minimum.
Tip: When specifying 6101-T6 bus bars, designers should verify that the conductivity requirement (58% IACS) is not compromised by the tempering process. In some cases, a slightly lower strength (T61) is specified to achieve a higher conductivity.
Dimensional Tolerances
CAN/CSA C50068 references ANSI H35.2 and H35.2(M) for dimensional tolerances on extruded shapes. For wire, it adopts the tolerances of the American Wire Gauge (AWG) system, with allowances for cross-sectional area and ovality. Round rods and tubes must conform to specified outer diameter and wall thickness tolerances, typically ±2% for diameters up to 25 mm and ±1.5% for larger sizes.
Implementation and Testing Highlights
To demonstrate compliance, manufacturers must perform both type tests (for design verification) and routine tests (for production consistency). Key test procedures include:
- Chemical analysis: Spectrochemical methods per ASTM E1251 or equivalent.
- Tensile testing: Per ASTM B557, at room temperature.
- Conductivity measurement: Using a Kelvin bridge or eddy-current instrument calibrated to a standard reference (e.g., NIST SRM).
- Dimensional verification: Using micrometers, calipers, and go/no-go gauges.
- Visual and surface quality inspection: For cracks, seams, lap marks, and oxidation spots.
Third-party certification by an accredited laboratory (e.g., CSA, UL, or Intertek) is strongly recommended for products used in critical power infrastructure. The standard does not mandate third-party certification, but Canadian electrical codes (e.g., CSA C22.1) often require products to be listed or certified to a recognized standard.
Implementation Note: Because the standard was reaffirmed in 2016 without technical changes, it does not reflect recent developments in high-conductivity alloys (e.g., 8000-series) or advanced extrusion techniques. Engineers should evaluate whether specific performance requirements exceed the conservative limits of C50068-99 (R2016).
Compliance Notes
Compliance with CAN/CSA C50068-99 (R2016) is typically verified through one of two pathways:
- Self-declaration with supporting test data: Manufacturers maintain a quality control system (e.g., ISO 9001) and provide a certificate of compliance (CoC) with each shipment, referencing the standard.
- Product certification by a recognized body: The product bears a certification mark (e.g., CSA or cCSAus) indicating ongoing surveillance testing.
The Canadian Electrical Code (CEC), Part I (CSA C22.1), accepts products conforming to CAN/CSA C50068 for use in electrical installations. However, some provincial authorities may require additional approvals for specific applications (e.g., underground enclosures or high-seismic zones).
Compliance Tip: Always confirm that the shipped product matches the alloy-temper designation and conductivity level stated in the CoC. A simple conductivity test at incoming inspection can prevent costly installation failures.
Warning: Using an alloy not listed in the standard (e.g., 5052 or 3003) for current-carrying purposes may violate the CEC and void equipment warranties. Verify each product’s alloy designation against Table 1 of the standard.
Frequently Asked Questions
Q: Is CAN/CSA C50068-99 (R2016) still active?
A: Yes, as of 2026 the standard is considered current. It was reaffirmed by CSA Group in 2016, meaning the technical committee found no need for updates at that time. However, check the CSA Store for the latest status, as a revision (C50068-19 or later) may have been published recently.
A: Yes, as of 2026 the standard is considered current. It was reaffirmed by CSA Group in 2016, meaning the technical committee found no need for updates at that time. However, check the CSA Store for the latest status, as a revision (C50068-19 or later) may have been published recently.
Q: Can I use this standard for extruded aluminium in welded bus bar assemblies?
A: The standard covers the base material requirements; it does not address weldability or post-weld properties. For welded assemblies, additional qualifications per CSA W59 or AWS D1.2 are necessary, and the heat-affected zone may experience reduced conductivity.
A: The standard covers the base material requirements; it does not address weldability or post-weld properties. For welded assemblies, additional qualifications per CSA W59 or AWS D1.2 are necessary, and the heat-affected zone may experience reduced conductivity.
Q: What is the difference between CAN/CSA C50068 and ASTM B317?
A: ASTM B317 is a similar standard for extruded aluminium bus bar. CAN/CSA C50068 adopts some of its requirements but includes Canadian-specific tolerances (via ANSI H35.2) and references. Both are commonly accepted, but the CSA version is mandatory in jurisdictions that adopt the CEC.
A: ASTM B317 is a similar standard for extruded aluminium bus bar. CAN/CSA C50068 adopts some of its requirements but includes Canadian-specific tolerances (via ANSI H35.2) and references. Both are commonly accepted, but the CSA version is mandatory in jurisdictions that adopt the CEC.
Q: Does this standard cover continuous cast rod used for wire drawing?
A: C50068 applies to extruded products. Continuous cast rod (e.g., Conform-processed) is typically covered by separate standards such as CAN/CSA C49.3 or ASTM B800. If the rod is later extruded into finished shapes, C50068 may apply to the final extrusion.
A: C50068 applies to extruded products. Continuous cast rod (e.g., Conform-processed) is typically covered by separate standards such as CAN/CSA C49.3 or ASTM B800. If the rod is later extruded into finished shapes, C50068 may apply to the final extrusion.
— Technical Reference Document — CAN/CSA C50068-99 (R2016) — Published for general informational purposes. 2026 edition.