The grade is identical and the price is lower—but is the delivered material doing the same job?
Decode quenched-and-tempered, annealed and as-rolled steel conditions, then compare quotations by machinability, final properties, process responsibility, lead time and MTC evidence.
A steel designation without its delivery condition is incomplete. +QT, +A and +AR describe materially different starting points for machining, heat treatment and acceptance, so quotations are comparable only when condition and guaranteed properties are aligned.
This guide is intended for designers, buyers, heat-treatment teams and workshops supplying parts across Iran. It translates a familiar market enquiry into requirements that can be checked before payment, cutting, machining or furnace work.
Quick decision map
| Question | Why it matters | Required evidence |
|---|---|---|
| Guaranteed state | Determines which properties the supplier certifies at delivery | Condition symbol, hardness and mechanical results on the MTC |
| Machining plan | Hardness, structure and residual stress change cutting behaviour | Initial hardness, stock allowance, straightness and tool strategy |
| Heat-treatment responsibility | A later Q&T cycle transfers process and distortion risk | Responsible party, furnace route, coupons and final acceptance |
| Comparable commercial scope | Cheap stock may require extra time, testing and yield loss | Price, lead time, processing, test cost and rejection exposure |
Identity, standard and the real engineering question
+QT normally indicates quenching and tempering to a declared property state; +A indicates annealing for a softer, process-ready state; +AR indicates as rolled. The governing product standard defines the exact meaning and certificate obligations.
+A is useful when rough machining precedes a controlled final heat treatment. +QT can shorten the route when supplied dimensions and certified properties suit the component. +AR should not be read as a promise of annealed machinability or final Q&T performance.
Guaranteed state
Determines which properties the supplier certifies at delivery. Record Condition symbol, hardness and mechanical results on the MTC before commercial comparison begins. If this field remains verbal, purchasing, production and inspection can each interpret the same requirement differently.
Machining plan
Hardness, structure and residual stress change cutting behaviour. The order should therefore require Initial hardness, stock allowance, straightness and tool strategy. Catalogue data becomes useful only after product form, section and test condition are made comparable.
Section, process and delivered condition
Section size changes cooling rate, property distribution, sampling position and sometimes the applicable property range. Product form also matters: bar, plate and forging may share a grade name but follow different dimensional, testing and delivery requirements.
Read the condition beside the dimensional range because guaranteed properties can vary by section. If stock will be cut, require heat-number transfer so each piece remains linked to its certificate through machining and furnace operations.
Inspection evidence that closes the decision
Evidence should answer a defined question. An MTC records heat identity and declared results; a process record proves the route used; a supplementary test report proves a result at a stated location. None of them should be treated as a substitute for the other two.
Heat-treatment responsibility
A later Q&T cycle transfers process and distortion risk. Define Responsible party, furnace route, coupons and final acceptance and identify the point where production must stop if the evidence is missing or outside the agreed range.
Comparable commercial scope
Cheap stock may require extra time, testing and yield loss. Release should be based on Price, lead time, processing, test cost and rejection exposure, attached to the same heat and piece identity. A valid test report has limited conformity value after traceability has been lost.
A defensible purchase specification
State the full grade and standard, product form, dimensions, required +A/+QT/+AR condition, hardness range, mechanical tests and location, impact temperature if applicable, UT class, straightness, MTC type and heat-number marking after cutting.
Grade/material number: [complete]; standard and edition: [complete]; form and dimensions: [complete]; delivery condition: [complete]; quantity and cutting tolerance: [complete]; MTC type: [complete]; supplementary test and acceptance rule: [complete]. Topic-specific requirement: State the full grade and standard, product form, dimensions, required +A/+QT/+AR condition, hardness range, mechanical tests and location, impact temperature if applicable, UT class, straightness, MTC type and heat-number marking after cutting.
Ordering checklist for Tehran, Tabriz, Isfahan and Yazd
- Write the recognised market term, but place +QT, +A or +AR and the documented designation on the same enquiry.
- Close Guaranteed state with Condition symbol, hardness and mechanical results on the MTC.
- Close Machining plan with Initial hardness, stock allowance, straightness and tool strategy.
- Define Heat-treatment responsibility before irreversible processing.
- Keep Comparable commercial scope traceable through cutting, storage and loading.
- State destination, required dispatch date, packaging, piece count and who authorises release.
Related encyclopaedia pages and guides
- 42crmo4 1 7225
- 34crnimo6 1 6582
- Previous Week-01 technical guide
- Next Week-01 technical guide
- Alloy-steel encyclopaedia
- Evidence and calculation methodology
- Contact Shaygan Steel
Frequently asked questions
Is +QT always ready for final use?
No. Verify dimensions, certified section range, actual properties, machining effects and any component-specific final treatment.
Is +A always easier to machine?
It is commonly selected for a softer starting state, but actual machinability still depends on grade, structure, hardness, inclusions and tooling.
Why can +AR be cheaper?
It may include less downstream processing, but the buyer may inherit heat-treatment, time, distortion, testing and rejection costs.
Sources and method
This article uses the official references below as technical orientation and translates them into a procurement workflow for the Iranian market. A producer data sheet applies to the product and conditions it states; it does not replace the current purchase standard, drawing or MTC for the delivered heat.
- Ovako Steel Navigator — official technical reference
- Ovako Steel Navigator — official technical reference
- Ovako Heat Treatment Guide — official technical reference
Conclusion and next step
Compare steel offers condition-for-condition, not grade-for-grade alone. The right suffix makes process ownership, property evidence and total finished cost visible before purchase.
For an enquiry, send material number, form, raw and final dimensions, quantity, delivery condition, inspection needs and destination in one message. Shaygan Steel can then review the evidence for current stock before proposing a supply route.
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