Material data
18CrNiMo7-6 case-hardening steel material
ISO 683-3:2022 case-hardening steel data. Chemical composition, delivery hardness, hardenability and heat-treatment conditions are listed separately. Supply form and condition require technical review and order confirmation.
Technical material data
Technical material data
18CrNiMo7-6 · ISO 683-3:2022
Chemical composition · Cast analysis
Mass fraction %; Table 3, page 18 of the user's PDF. Unlisted elements must not be treated as 0; intentional addition of unlisted elements is subject to the standard and ordering agreement.
| Element | Mass fraction / % |
|---|---|
| C | 0.15～0.21 |
| Si | ≤0.4 |
| Mn | 0.5～0.9 |
| P | ≤0.025 |
| S | ≤0.035 |
| Cr | 1.5～1.8 |
| Mo | 0.25～0.35 |
| Ni | 1.4～1.7 |
| Cu | ≤0.4 |
A.4 does not explicitly list a minimum silicon content under this exact grade designation. No minimum is assigned automatically; confirm in the order if required.
Delivery conditions and hardness · Table 7
Brinell hardness. +S: treated to improve shearability; +A: soft annealed; +TH: treated to a specified hardness range; +FP: treated to a ferrite-pearlite structure; +N: normalized. “—” means no requirement is specified for that delivery condition.
| Delivery condition | Brinell hardness requirement |
|---|---|
| +S | ≤255 |
| +A | ≤229 |
| +TH | 179～229 |
| +FP | 159～207 |
| +N | — |
Heat treatment and test-piece conditions · Table 8
| Item | Temperature / ℃ |
|---|---|
| Austenitizing temperature for the end-quench test | 860 ± 5 |
| Carburizing temperature (guidance) | 880～980 |
| Direct and first quenching temperature (guidance) | 810～850 |
| Second quenching: core quenching temperature (guidance) | 830～870 |
| Second quenching: case quenching temperature (guidance) | 780～820 |
| Tempering temperature (guidance) | 150～200 |
Except for the end-quench austenitizing temperature, carburizing, quenching and tempering temperatures are guidance values; the actual process must achieve the required properties. Guidance holding times are at least 30 minutes for austenitizing and at least 1 hour for tempering. Select the quenching medium according to product shape, cooling conditions and furnace load.
Hardenability conditions · Tables 5 and 6
Distance from the quenched end in mm; hardness in HRC. Apply only when the corresponding hardenability condition is specified in the order. “—” indicates that no limit is specified at that position.
+H · Normal hardenability
| Limit / Distance mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum | 48 | 48 | 48 | 48 | 47 | 47 | 46 | 46 | 44 | 43 | 42 | 41 | 41 |
| Minimum | 40 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 32 | 31 | 30 | 29 | 29 |
+HH · Restricted hardenability band
| Limit / Distance mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum | 48 | 48 | 48 | 48 | 47 | 47 | 46 | 46 | 44 | 43 | 42 | 41 | 41 |
| Minimum | 43 | 43 | 42 | 41 | 40 | 40 | 39 | 38 | 36 | 35 | 34 | 33 | 33 |
+HL · Restricted hardenability band
| Limit / Distance mm | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum | 45 | 45 | 45 | 45 | 44 | 43 | 42 | 42 | 40 | 39 | 38 | 37 | 37 |
| Minimum | 40 | 40 | 39 | 38 | 37 | 36 | 35 | 34 | 32 | 31 | 30 | 29 | 29 |
Permissible deviations in product analysis · Table 4
| Element | Specified cast-analysis range / % | Permissible product-analysis deviation / % |
|---|---|---|
| C | 0.07<C≤0.31 | ±0.02 |
| Si | ≤0.40 | ±0.03 |
| Mn | ≤1.00 / >1.00～1.65 | ±0.04 / ±0.06 |
| P | ≤0.025 | +0.005 |
| S | ≤0.040 | ±0.005 |
| Cr | ≤1.80 | ±0.05 |
| Mo | ≤0.30 / >0.30～0.50 | ±0.03 / ±0.04 |
| Ni | ≤1.00 / >1.00～2.00 / >2.00～3.50 | ±0.03 / ±0.05 / ±0.07 |
| Cu | ≤0.40 | +0.05 |
| B | ≤0.0050 | ±0.0003 |
“±” permits a deviation for a single cast above the upper limit or below the lower limit, in one direction only. Product-analysis deviations do not change the cast-analysis limits in Table 3.
Standard edition and ordering notes
- ISO 683-3:2022; the user-supplied file is the EN ISO 683-3:2022 adoption. Requirements from different editions are listed separately; existing sources are retained.
- The 2022 edition removes the minimum silicon content from Table 3. The basic requirement is Si≤0.40%; the minimum in Annex A.4 applies only as an expressly agreed ordering option.
- Annex A.4 prints 15MnCrS5 and 18CrMo7-6, which differ from the grade designations in Table 3. This page does not silently correct them or assign a minimum silicon content automatically; additional requirements must be agreed by purchaser and supplier.
- When ordered to hardenability requirements, Table 3, footnote a permits limited minor composition deviations: excluding P and S, C ±0.01%, and other elements within the Table 4 limits. These are not default ranges for ordinary orders.
- High-sulfur or lead-added free-cutting variants apply only at the purchaser's request and subject to agreement; they do not replace the ordinary composition ranges shown here.
The standard covers products including wire rod. Finished cold-heading wire supply, processing and properties require technical review and order confirmation. — means not specified in this table, not 0.
Source comparison: reviewed by Codex against the standard supplied by the user. This webpage does not replace the official standard, order agreement or inspection certificate.
TECHNICAL NOTE
Application and ordering note
Chemical composition, mechanical properties, delivery condition and other technical requirements are subject to the currently applicable standard edition, customer drawings and the order technical agreement. Website information does not replace formal quality certification documents.
RFQ CHECKLIST
What to include in the enquiry
- Grade and applicable standard
- Diameter or section, delivery condition and quantity
- Part drawing, forming stations or failure photos, if available
- Testing, certificate or report requirements
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