Searchable designation reference
Steel Grades Chart and Lookup
Common U.S.-market identifiers with scope and condition checks.
Verify before specifying
A grade name alone may not define product form, condition, heat treatment, thickness-dependent properties, testing, toughness, weldability requirements, or acceptance criteria. Verify the complete governing specification and material certification.
Search a designation or application, filter by family, and select one row to keep it highlighted. The interpretation columns explain what the identifier establishes and what still needs confirmation.
No matching grade is included in this curated chart. Check the designation format or consult the current issuing standard or supplier documentation; do not assume the closest-looking grade is equivalent.
Scroll horizontally to view additional columns and vertically to view additional rows. Column headers remain visible while scrolling.
| Select | Identification | Engineering interpretation | Traceability | |||||
|---|---|---|---|---|---|---|---|---|
| What it identifies | Typical context | Confirm before use | ||||||
| ASTM A36 | Structural | Carbon structural steel | Product/material specification | Structural steel products within the specification scope | General structural plates, shapes, and bars | Product form and thickness; supplementary/project requirements; welding procedure; certification | ASTM A36/A36M |
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| ASTM A572 Grade 50 | Structural | High-strength low-alloy | Product/material specification | A grade within a structural HSLA product specification | Structural products where the specification applies | Product form and thickness; toughness/supplementary requirements; welding; certification | ASTM A572/A572M |
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| ASTM A992 | Structural | Structural shapes | Product/material specification | Structural shapes within the specification scope | Rolled structural shapes for building framing | Shape and dimensions; project/toughness requirements; welding; certification | ASTM A992/A992M |
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| ASTM A500 Grade C | Structural | Structural tubing | Product/material specification | A grade within a structural tubing specification | Round and shaped structural tubing | Shape and wall thickness; manufacture route; project requirements; welding; certification | ASTM A500/A500M |
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| SAE 1018 | Carbon | Low-carbon steel | Composition grade | An SAE carbon-steel composition designation | Cold-finished bar and general machined parts | Product specification and form; hot/cold-finished condition; size, properties, tolerances | SAE J403 |
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| SAE 1020 | Carbon | Low-carbon steel | Composition grade | An SAE carbon-steel composition designation | General carbon-steel products and components | Product specification and form; condition and section size; properties; certification | SAE J403 |
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| SAE 1045 | Carbon | Medium-carbon steel | Composition grade | An SAE carbon-steel composition designation | Shafts, axles, pins, and machine components | Product specification and size; supplied/heat-treated condition; target properties; certification | SAE J403 |
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| SAE 1095 | Carbon | High-carbon steel | Composition grade | An SAE high-carbon-steel composition designation | Springs, strip, and selected wear or edge applications | Product form and thickness; supplied condition; heat treatment; toughness; certification | SAE J403 |
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| SAE 4130 | Alloy | Chromium-molybdenum | Composition grade | An SAE Cr-Mo alloy-steel composition designation | Tubing, fittings, and engineered components | Product specification and size; condition/heat treatment; welding; properties; certification | SAE J404 |
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| SAE 4140 | Alloy | Chromium-molybdenum | Composition grade | An SAE Cr-Mo alloy-steel composition designation | Heat-treated shafts, gears, axles, and machine parts | Product specification and size; supplied/heat-treated condition; properties, testing, certification | SAE J404 |
|
| SAE 4340 | Alloy | Nickel-chromium- molybdenum | Composition grade | An SAE Ni-Cr-Mo alloy-steel composition designation | Highly loaded aerospace and power-transmission components | Product specification and size; cleanliness; heat treatment; toughness, testing, certification | SAE J404 |
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| SAE 8620 | Alloy | Ni-Cr-Mo carburizing steel | Composition grade | An SAE low-alloy-steel composition designation | Carburized gears, shafts, and case-hardened parts | Product specification and size; case/core requirements; heat treatment; testing; certification | SAE J404 |
|
| Type 304 | Stainless | Austenitic | Stainless type / common designation | A common stainless type; not a complete purchase specification | General corrosion-resistant equipment and components | Product specification and form; finish/condition; environment; fabrication; certification | ASTM A240/A240M scope |
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| Type 304L | Stainless | Low-carbon austenitic | Stainless type / common designation | A low-carbon austenitic type; product requirements still vary | Welded corrosion-resistant fabrications | Product specification and form; certification basis; finish/environment; welding; testing | ASTM A240/A240M scope |
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| Type 316 | Stainless | Mo-bearing austenitic | Stainless type / common designation | A Mo-bearing austenitic type; not a universal service rating | Process and corrosion-resistant equipment after environment review | Product specification and form; finish; chloride/temperature exposure; fabrication; certification | ASTM A240/A240M scope |
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| Type 316L | Stainless | Low-carbon Mo-bearing austenitic | Stainless type / common designation | A low-carbon Mo-bearing type; form and suitability remain open | Welded process and corrosion-resistant fabrications | Product specification and form; certification basis; environment; welding; testing | ASTM A240/A240M scope |
|
| Type 410 | Stainless | Martensitic | Stainless type / common designation | A martensitic stainless type; properties depend on condition | Valves, fasteners, blades, and wear components | Product form; supplied condition; heat treatment; hardness/toughness; environment; certification | ASTM A240/A240M scope |
|
| Type 430 | Stainless | Ferritic | Stainless type / common designation | A ferritic stainless type; product and finish still matter | Appliances, trim, and moderately corrosive service | Product specification and form; finish; forming/welding; temperature/environment; certification | ASTM A240/A240M scope |
|
| 17-4 PH | Stainless | Precipitation-hardening | Stainless type / common designation | A PH stainless designation; final condition is essential | Aerospace, valves, shafts, and high-strength components | Product specification and size; solution/aging condition; toughness; environment, testing, certification | ASTM A240/A240M scope |
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| 2205 | Stainless | Duplex | Stainless type / common designation | A duplex stainless designation; exact UNS/product basis is required | Process, chemical, marine, and chloride-bearing service | Exact UNS and product basis; heat treatment; welding; environment, testing, certification | ASTM A240/A240M scope |
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| O1 | Tool | Oil-hardening cold-work | Tool-steel type | An oil-hardening cold-work tool-steel type | Gauges, knives, punches, and tooling | Product specification and size; supplied condition; heat treatment; hardness; distortion; certification | ASTM A681 |
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| A2 | Tool | Air-hardening cold-work | Tool-steel type | An air-hardening tool-steel type; not an A2 fastener designation | Punches, dies, gauges, and wear tooling | Identifier context; product basis; supplied condition; heat treatment; hardness/toughness; certification | ASTM A681 |
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| D2 | Tool | High-carbon, high-chromium cold-work | Tool-steel type | A cold-work tool-steel type; condition controls performance | Dies, shear blades, punches, and wear tooling | Product specification and size; supplied/heat-treated condition; hardness, toughness, certification | ASTM A681 |
|
| S7 | Tool | Shock-resisting | Tool-steel type | A shock-resisting tool-steel type | Impact tooling, punches, chisels, and shears | Product specification and size; supplied condition; heat treatment; impact/hardness needs; certification | ASTM A681 |
|
| H13 | Tool | Chromium hot-work | Tool-steel type | A chromium hot-work tool-steel type | Die casting, extrusion, and hot-work tooling | Product specification and cleanliness; size; heat treatment/tempering; service temperature; certification | ASTM A681 |
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| M2 | Tool | Molybdenum high-speed | Tool-steel type | A molybdenum high-speed tool-steel type | Drills, taps, milling cutters, and cutting tools | Product specification; condition; heat treatment; hardness; service/coating needs; certification | ASTM A681 |
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This chart is a curated designation guide, not a reproduction of standards tables or a material-selection approval. Confirm the active standard, product form, condition, dimensions, required properties, testing, and certification.
More filters and actions
How to Read the Steel Grades Chart
- Find the designation. Search by grade, common alias, family, application, or issuing system. Punctuation and capitalization do not need to match exactly.
- Check the identifier basis. A composition grade, product specification, stainless type, and tool-steel type do not communicate the same information.
- Read “Confirm before use.” Those items close the gap between a familiar name and a complete design or purchase requirement.
- Follow the source path. Confirm the active edition and the specification that applies to the exact product form being purchased.
Selecting a row highlights it for focused review. Use Copy row to copy the visible interpretation and source path; selection never means the site has approved that material.
Steel Grade, Specification, and Condition Are Not the Same Thing
| Layer | What it contributes | What it does not settle by itself |
|---|---|---|
| Composition designation | Places the steel in a chemical-composition family. | Final strength, hardness, form, tolerances, testing, or delivery condition. |
| Product specification | Defines scope and requirements for specified products and grades. | Project-specific supplementary requirements or fitness for a particular service. |
| Product form and size | Identifies bar, plate, sheet, tubing, shape, forging, or another supplied form. | Heat treatment, finish, test requirements, or application acceptance. |
| Condition and processing | States hot rolled, cold finished, annealed, normalized, quenched and tempered, aged, or another condition. | The complete purchase specification or service suitability. |
Why the chart does not list one strength or hardness
Mechanical properties can change materially with product specification, form, section size, processing, heat treatment, test orientation, and whether a published value is a required minimum or merely typical. One universal value beside “4140,” “410,” or “D2” would hide those dependencies and create false precision.
For broader background on structural steel behavior and selection, see steel materials and engineering design.
How Steel Designation Systems Differ
SAE carbon and alloy steel numbers
In the familiar four-digit SAE system, the leading digits identify a broad carbon or alloy family, while the final two digits conventionally indicate approximate nominal carbon content in hundredths of a percent. The convention is useful for decoding families, but exceptions and suffixes exist, and the number does not establish final mechanical properties.
- SAE 1018
- The 10xx family denotes a plain-carbon-steel family; “18” follows the approximate carbon-content convention. The supplied product and condition still control usable properties.
- SAE 4140
- The 41xx family identifies chromium-molybdenum alloy steel; “40” follows the approximate carbon convention. Section size and heat treatment strongly affect the final result.
Structural, stainless, and tool-steel identifiers
| System | Example | Interpretation |
|---|---|---|
| ASTM structural specification | ASTM A36 | A product/material specification with a defined scope—not simply a four-digit composition grade. |
| Stainless type/common name | Type 316L | A meaningful alloy/type designation whose low-carbon suffix matters, but which still needs a product specification and form. |
| Tool-steel type | A2 | An air-hardening cold-work tool-steel type in this context; it must not be confused with an A2 stainless fastener designation. |
Worked Grade-Interpretation Examples
Example 1: SAE 4140 shaft
Starting point: A designer calls for “4140” for a machined shaft. The designation identifies an SAE chromium-molybdenum composition family.
- Choose the applicable bar, forging, or other product specification.
- State diameter or section size and delivery condition.
- Define heat treatment and required mechanical or hardness acceptance criteria.
- Define testing, inspection, tolerances, and certification.
Sanity check: A property value from an unrelated diameter or heat-treatment condition cannot be assumed for this shaft.
Example 2: ASTM A36 structural plate
Starting point: A detail calls for ASTM A36 plate. Here the identifier points to a structural product specification rather than an SAE composition grade.
- Confirm that the product form and thickness fall within the applicable specification scope.
- Apply project drawings, dimensions, tolerances, and supplementary requirements.
- Confirm the welding procedure and any toughness or service-temperature requirements.
- Require the appropriate material certification and inspection records.
Sanity check: “A36” does not automatically mean the material is interchangeable with SAE 1018.
Comparing or Substituting Steel Grades Safely
A designation that looks similar in another system is a candidate for evaluation, not an automatic equivalent. Check all of the following before accepting a substitution:
- Required chemistry limits and permissible product analysis variation
- Mechanical-property requirements, test direction, and section-size range
- Toughness, temperature, fatigue, wear, and corrosion requirements
- Product form, dimensional tolerances, finish, and manufacturing route
- Supplied condition, heat treatment, and permitted repair or processing
- Weldability, qualified welding procedure, and postweld requirements
- Standard edition, project acceptance criteria, testing, traceability, and certification
Decision rule: If the drawing, code, customer specification, or authority having jurisdiction names a material standard, obtain documented approval before substituting another designation.
Sources, Scope, and Data Rights
Turn2Engineering curated designation reference—source checked August 10, 2026.
This page uses official standards metadata, public scope information, limited factual designation references, and original explanatory summaries. It does not reproduce complete proprietary chemistry, mechanical-property, heat-treatment, hardness, or UNS cross-reference tables.
- SAE J403_202402—Chemical Compositions of SAE Carbon SteelsFebruary 2024. Supports the SAE carbon-steel designation basis and its composition scope; it does not establish finished-product properties or condition.
- SAE J404_200901—Chemical Compositions of SAE Alloy SteelsJanuary 2009. Supports common SAE alloy-steel composition families; product specifications and condition remain separate.
- ASTM E527-23—Unified Numbering System practiceSupports the distinction between an alloy identifier and a material specification. A UNS number does not define form, condition, quality, or complete purchase requirements.
- ASTM A36/A36M, ASTM A572/A572M, ASTM A992/A992M, and ASTM A500/A500MPublic catalog scopes support the structural product-specification rows. Each designation remains limited to the products, grades, conditions, and requirements in its current complete standard.
- ASTM A240/A240M and ASTM A681-24Public catalog scopes support the distinction between stainless plate/sheet/strip specifications and wrought alloy tool-steel products. The complete active standards control.
Dataset and Source-Check Details
- Dataset
- 26 common U.S.-market structural, SAE carbon, SAE alloy, stainless, and tool-steel identifiers
- Primary fields
- Designation family, identifier basis, typical context, confirmation requirements, and source path
- Excluded fields
- Universal strength, hardness, elongation, machinability, corrosion ratings, chemistry matrices, and automatic international equivalents
- Rights decision
- Bounded editorial reference only; no bulk CSV or standards-table download
- Missing-value policy
- Condition-dependent information is described explicitly rather than shown as zero or an unexplained blank
- Publisher
- Turn2Engineering
Steel Grades Chart FAQs
In the SAE system, the leading digits identify a broad alloy family and the final two conventionally indicate approximate nominal carbon content in hundredths of a percent. The designation does not define final heat-treated properties, product form, or section size.
No. ASTM A36 is a structural product/material specification, while SAE 1018 is principally a composition designation. Some characteristics may overlap in particular products, but they are not automatic equivalents.
There is no universal answer. Strength depends on the alloy, product specification, condition, heat treatment, section size, test method, and whether yield, tensile, fatigue, impact, or another property controls the design.
Only after verifying chemistry, mechanical requirements, product form, dimensions, condition, heat treatment, testing, certification, standard editions, and project acceptance. A cross-reference is a comparison starting point, not substitution approval.
Those properties often vary with product form, dimensions, processing, heat treatment, test orientation, and governing specification. A single number without those conditions would be misleading.
Use the Designation as a Starting Point
The fastest safe workflow is to identify the naming system, confirm what the designation actually controls, then complete the product specification, form, size, condition, properties, testing, and certification. This chart helps organize that work without presenting false universal properties or automatic equivalents.