Electrical flat bar buying guide
Compare the complete material specification, not just the alloy number.
For electrical aluminium flat bar, choose between 1060, 1070 and 1350 by checking the approved alloy, temper, conductivity requirement and product specification together. Higher aluminium purity alone does not prove that one bar can replace another. If the drawing names 1350, a 1060 or 1070 proposal needs approval even if its quoted conductivity looks suitable.
This guide helps purchasing teams turn an alloy comparison into a clearer enquiry and a better document check. The final material choice belongs to the equipment design and its acceptance requirements.
1. What actually differs between 1060, 1070 and 1350?
These are separate high-purity aluminium grades with different composition limits. The aluminium percentage is a useful starting point, but it is not an electrical performance certificate.
| Grade | Minimum aluminium content | What to do with that information |
|---|---|---|
| 1060 | 99.60% | Check the required temper and electrical properties; purity alone does not qualify the bar. |
| 1070 | 99.70% | Keep the exact designation and product form clear; do not assume the higher minimum purity makes it an approved substitute. |
| 1350 | 99.50% | Check the electrical-bar specification and temper required by the project. |
The composition figures come from The Aluminum Association's Teal Sheets, December 2025, page 1, for the exact designations shown. The record also sets limits for other elements. Do not treat 1070 and 1070A, or 1350 and 1350A, as the same designation without checking the applicable specification.
Why is 1350 common in electrical-bar specifications despite its lower minimum purity? Composition and the required electrical properties are separate checks. ASTM B236/B236M-23 specifically covers 1350 electrical bars and identifies H12, H111 and H112 tempers. Its public abstract includes electrical conductivity and resistivity testing.
2. Why does the temper matter as much as the grade?
The alloy identifies the composition; the temper identifies the material's processing condition. Two bars with the same alloy number can have different mechanical properties when their tempers differ.
For bending or forming
Tell the supplier what happens after delivery. Specify the bend geometry, direction and acceptance requirement on the drawing. Confirm the proposed alloy-temper combination and any trial requirement before ordering.
For a supported conductor
Keep the mechanical requirements in the material enquiry. The design must account for support spacing and service loads; a conductivity figure does not tell you whether the bar has the required strength.
Hydro's Alloy 1xxx datasheet distinguishes F, O, H111 and H112 conditions. O means annealed to obtain the lowest-strength temper. F means as fabricated, with no mechanical property limits specified for that condition in the datasheet. The listed H tempers have their own property requirements.
Use the complete designation, such as 1350-H111, when the design requires it. Do not accept a quotation that quietly drops the temper, or use a bend-radius recommendation from another alloy-temper combination.
3. How should you read a conductivity claim?
Separate a typical reference value from an agreed minimum and a result for the supplied material. They answer different questions: what is usually expected, what must be met, and what was actually measured.
Conductivity is often expressed as % IACS, short for International Annealed Copper Standard. It compares conductivity with a copper reference; it is not the aluminium purity percentage or a percentage of allowable current.
A useful example from Hydro: its 2019 datasheet lists typical conductivity at 20°C of 62% IACS for both 1060-O and 1350-H111, while the 1350-H111 entry also states a 61.0% minimum. This shows why a “62%” headline is not the same as a minimum requirement.
These are published extrusion reference values, not test results for your order. The same table does not provide a conductivity figure for every listed temper, and it does not supply a 1070 comparison. Ask for evidence applicable to the actual grade, temper and product form offered.
For each electrical-property claim, check the units, reference temperature, test method, acceptance limit and link to the supplied batch. If the supplier gives resistance instead, ask for the specimen length and cross-section as well; a resistance number without geometry is not a like-for-like material comparison.
4. Which supplier proposals need clarification or change approval?
Start with your approved requirement, then classify each proposal before comparing prices. Use “matches the stated material description”, “needs clarification” or “needs change approval”. None of these labels replaces inspection or engineering acceptance.
Fictional buyer requirement
Drawing EB-106, revision C: 1350-H111 flat bar, minimum conductivity 61.0% IACS referenced to 20°C, dimensions and mechanical requirements as specified in the drawing and purchase specification.
This is an illustrative purchasing requirement, not a universal specification for all busbars.
Use the worksheet with your own approved inputs. Swipe sideways on mobile.
| Illustrative offer | Review status | Buyer's next action |
|---|---|---|
| 1350-H111; declared minimum 61.0% IACS at 20°C | Material description matches | Verify batch-linked evidence, dimensions and remaining requirements before acceptance. |
| 1350; conductivity quoted without temper or temperature | Needs clarification | Request the complete designation and electrical-property basis; do not assume H111. |
| 1070-O or 1060-H112 offered as an alternative | Needs change approval | Obtain the proposed material documents and refer the deviation to the responsible engineer. |
The output is a list of missing information and approval actions. An offer can look electrically promising and still differ from the approved mechanical or material requirement. Compare prices after those differences are resolved.
In your request for quotation, include the alloy-temper designation, applicable specification and revision, finished dimensions, quantity, electrical and mechanical requirements, subsequent processing and required inspection documents. Ask the supplier to list deviations explicitly.
Frequently asked questions
Which grade is the cheapest?
There is no reliable fixed ranking without current quotations for the same dimensions, temper, processing and inspection scope. Compare the total delivered scope after confirming suitability; an inexpensive alternative that needs approval or extra work is a different proposal.
Can I use one current rating for all three grades?
No. Current capacity depends on the conductor geometry, operating conditions, connections and equipment design as well as material properties. Have the designer verify the complete arrangement rather than converting an alloy name or % IACS value directly into amperes.
Does naming ASTM B236 prove that a bar complies?
No. The standard reference defines a requirement; compliance needs applicable evidence for the supplied product. Check the alloy, temper, product form and agreed edition. The public scope is useful for checking relevance, but it does not replace the full purchase specification.
Send a specification suppliers can compare
Browse the aluminium flat bar product range and use the sizes and specifications guide to organise the dimensional part of your enquiry.
Send your drawing, alloy-temper requirement and order quantity. Include conductivity requirements, requested documents and delivery destination. If you are comparing 1060, 1070 and 1350 aluminium flat bar, identify which alternatives your engineer is prepared to review.
