Aluminum hardness conversion needs a suitable material table and a clearly identified original test result. Retain the measured value, its hardness scale and the conversion reference. Mark a converted value as converted wherever it appears in a purchasing comparison.
Start with the source report. If an offer supplies only a bare number on a different scale, request the missing basis before comparing it with your requirement.
The three table checks
1. Check the aluminum hardness conversion table’s material scope
The ASTM E140 public overview describes approximate hardness conversions. Its tables have specified material scopes; Table 9 concerns wrought aluminum products.
ASTM also explains that conversion relationships depend on material characteristics. A table named for one material group does not establish a universal relationship for every metal.
Read the table heading before using its numbers
Retain the actual table number, referenced edition and stated material coverage in the review record. Ask the report issuer to identify the basis when a quotation merely says “converted according to ASTM.”
Keep the supplied alloy, temper and product form identifiable. A table reference and a material designation are separate fields; both need to be understandable to the reviewer.
If the material connection is unclear, leave the conversion as an open technical question. A familiar hardness-scale name cannot fill in a missing table scope.
Our material certificate guide explains how to retain the material and document connection. Carry that identity into the hardness comparison instead of reducing the material to the single word “aluminum.”
Ask what the comparison is meant to decide
Record the hardness requirement as it actually appears in the agreed specification. Keep its stated method or scale, applicable material and acceptance basis with the purchasing file.
If the requirement calls for a measured result, ask the responsible reviewer whether a converted entry is suitable evidence. Do not silently rewrite the requirement into another scale to match a convenient supplier document.
2. Keep the original test result available
A comparison sheet should show which value was actually measured. Retain the complete reported hardness designation and the source report reference, including the relevant test conditions recorded by the issuer.
The aluminum hardness testing guide discusses choosing and documenting a hardness method. This review starts with an issued result and asks how a later conversion is represented.
Follow the result from report to quotation
Locate the original report entry before evaluating the supplier’s converted number. Confirm that its specimen or material reference matches the value carried into the quotation.
Keep the original result unchanged in the record. If a supplier corrects a transcription error, request a traceable correction or revised document rather than replacing the original entry without explanation.
Identify who performed the conversion and where it was recorded. A laboratory report, supplier worksheet and purchasing summary may contain different kinds of entries, even when they are attached to the same order.
| Entry | What to retain |
|---|---|
| Measured result | Complete designation and original report reference. |
| Material | Alloy, condition and supplied product identity. |
| Conversion | Target scale, table, edition and stated limits. |
| Review decision | How the agreed requirement treats this evidence. |
Preserve a readable connection
Use clear column headings such as “Measured result” and “Converted estimate.” Keep the explanation in the same worksheet or in an explicitly referenced attachment.
If the purchasing system allows only one value field, retain a linked note that identifies the entry’s status. Avoid a shortened description that makes a converted estimate look like a second test.
3. Label the converted value and retain its limits
ASTM E140 cautions that conversions are approximate and recommends avoiding conversion of test data when possible. Preserve that status when the entry moves from a technical worksheet to a commercial offer.
A clearly labeled estimate gives the reviewer a useful question to resolve. An unlabeled number hides whether the supplier measured the requested scale or translated another result.
Separate the conversion from the acceptance decision
Document whether the responsible reviewer accepts the supplied evidence for the particular requirement. Keep that decision with its scope and any outstanding requests.
Do not interpret a converted hardness entry as an unreported strength value or a finished-part approval. Request the evidence named in the actual material or component requirement.
For a local indentation result, keep the tested location identifiable where it matters to the review. The Knoop and Vickers comparison discusses method and location questions without supplying a universal conversion between scales.
An original fictional worksheet: order H58
Imagine two offers for order H58. Offer A retains its measured hardness designation and shows a separately labeled converted estimate with a named table. Offer B lists the target scale but omits whether that entry was measured or converted.
The buyer requests the original result and conversion basis for B. The buyer also asks the material reviewer whether the documented evidence addresses the agreed requirement.
Please identify the measured hardness entry behind the H58 quotation. If the quoted value is converted, retain its original designation, table reference and material scope, and label the converted entry clearly.
H58 is an invented document-review example. It contains no hardness values, conversion factors, actual supplier reports or acceptance outcome.
Close the question with an identifiable response
Retain the supplier’s clarification and the reviewer’s decision with the order. If a revised report replaces an earlier worksheet, preserve its revision and the connection between the documents.
This keeps procurement and quality working from the same evidence. A later change to the offered material or reporting basis can then be recognized and reviewed.
Carry the approved material identity into cutting
Send JiurunCut the identified aluminum material and representative cut list. Include drawings, blank dimensions, quantities and any agreed documentation requirements for the equipment discussion.
Keep aluminum hardness conversion evidence with the responsible material reviewer. Carry the approved alloy, supplied condition and document reference into the cutting order.
Can a table reference alone complete the comparison?
Retain the original measured entry, material connection and converted-value status with it.
Is a converted entry another measured result?
Keep it labeled as converted and preserve the actual test report separately.