Steel Grades Chart — Common ASTM, SAE, Stainless & Tool Steels
Need a grade fast? Search 4140, 304, A36, D2, shafts, corrosion, structural tubing, or tooling. The chart shows the grade family, steel type, why it is commonly considered, typical uses, and the source path.
These are starting points, not automatic material selections. Final suitability depends on the product specification, form, condition, heat treatment, dimensions, service environment, and required properties.
No matching grade is included in this 26-grade reference. Try the designation only (for example 4140, 316, A36, or D2), a family such as stainless, or an application such as shafts or tooling.
Scroll horizontally to view all columns and vertically to view additional grades. The grade column remains available as the row header.
| Compare | Why it’s considered | Typical use | Standard / source | |||
|---|---|---|---|---|---|---|
| ASTM A36 | Structural | Carbon structural steel | General-purpose structural carbon steel with broad use in fabricated structural products. | General structural plates, shapes, and bars | ASTM A36/A36M-19 | |
| ASTM A572 Grade 50 | Structural | High-strength low-alloy structural steel | High-strength low-alloy structural grade used when a higher specified strength level is needed. | Structural plate, shapes, sheet piling, and bars where the specification applies | ASTM A572/A572M-25 | |
| ASTM A992 | Structural | Structural shapes | Structural-shape specification widely used for rolled building-framing shapes. | Rolled structural shapes used in building framing | ASTM A992/A992M-22 | |
| ASTM A500 Grade C | Structural | Structural tubing | Cold-formed structural-tubing grade for round and shaped HSS products. | Round and shaped structural tubing where the specification applies | ASTM A500/A500M-23 | |
| SAE 1018 | Carbon | Low-carbon steel | Low-carbon steel commonly chosen for general machining, forming, and fabricated components. | Commonly specified for cold-finished bar and general machined parts, subject to product specification | SAE J403_202402 | |
| SAE 1020 | Carbon | Low-carbon steel | Low-carbon composition used across many general-purpose carbon-steel products. | General carbon-steel products and components, subject to the applicable product specification | SAE J403_202402 | |
| SAE 1045 | Carbon | Medium-carbon steel | Medium-carbon steel with more heat-treatment and hardness potential than low-carbon grades. | Shafts, axles, pins, and machine components where the selected condition is suitable | SAE J403_202402 | |
| SAE 1095 | Carbon | High-carbon steel | High-carbon steel selected when hardness and wear resistance are developed by suitable processing. | Springs, strip, and wear or edge applications after suitable processing | SAE J403_202402 | |
| SAE 4130 | Alloy | Chromium-molybdenum | Chromium-molybdenum alloy steel used for tubing and engineered components where controlled processing matters. | Tubing, fittings, and machine or aerospace components under an applicable product specification | SAE J404_200901 | |
| SAE 4140 | Alloy | Chromium-molybdenum | Chromium-molybdenum alloy steel with strong heat-treatment response for shafts, gears, axles, and machine parts. | Heat-treated shafts, gears, axles, fasteners, and machine components | SAE J404_200901 | |
| SAE 4340 | Alloy | Nickel-chromium-molybdenum | Nickel-chromium-molybdenum alloy steel for highly loaded components after controlled heat treatment. | Highly loaded aerospace, power-transmission, and machine components after controlled processing | SAE J404_200901 | |
| SAE 8620 | Alloy | Nickel-chromium-molybdenum carburizing steel | Low-alloy carburizing steel used when a hard case and tougher core are required. | Carburized gears, shafts, bushings, and other case-hardened components | SAE J404_200901 | |
| Type 304 | Stainless | Austenitic stainless steel | Austenitic stainless steel for general corrosion-resistant fabrication and equipment. | General corrosion-resistant fabricated equipment and components | ASTM A240/A240M-26 | |
| Type 304L | Stainless | Low-carbon austenitic stainless steel | Lower-carbon 304 variant commonly selected for welded corrosion-resistant fabrication. | Welded corrosion-resistant fabrications where the selected product specification permits | ASTM A240/A240M-26 | |
| Type 316 | Stainless | Molybdenum-bearing austenitic stainless steel | Molybdenum-bearing austenitic stainless used for more demanding corrosion exposure after environment review. | Process, food, architectural, and marine-adjacent equipment after environment review | ASTM A240/A240M-26 | |
| Type 316L | Stainless | Low-carbon molybdenum-bearing austenitic stainless steel | Lower-carbon 316 variant commonly selected for welded corrosion-resistant fabrication. | Welded process and corrosion-resistant fabrications after environment review | ASTM A240/A240M-26 | |
| Type 410 | Stainless | Martensitic stainless steel | Martensitic stainless steel whose useful hardness, strength, and toughness depend strongly on heat treatment. | Valves, fasteners, blades, and wear components after suitable heat treatment | ASTM A240/A240M-26 | |
| Type 430 | Stainless | Ferritic stainless steel | Ferritic stainless steel used in appliances, trim, and moderately corrosive service where its formability and finish fit. | Appliances, trim, and moderately corrosive service after suitability review | ASTM A240/A240M-26 | |
| 17-4 PH | Stainless | Precipitation-hardening stainless steel | Precipitation-hardening stainless steel used for high-strength corrosion-resistant components after aging condition is specified. | Aerospace, valve, shaft, and high-strength corrosion-resistant components | ASTM A693-24 · ASTM A564/A564M-25 | |
| 2205 | Stainless | Duplex stainless steel | Duplex stainless steel used where strength and resistance to chloride-bearing environments are important. | Process, chemical, marine, and chloride-bearing service after detailed environment review | ASTM A240/A240M-26 | |
| O1 | Tool | Oil-hardening cold-work tool steel | Oil-hardening cold-work tool steel used for gauges, knives, punches, and general tooling. | Gauges, knives, punches, and tooling after controlled heat treatment | ASTM A681-24 | |
| A2 | Tool | Air-hardening cold-work tool steel | Air-hardening cold-work tool steel balancing wear resistance, toughness, and dimensional stability. | Punches, dies, gauges, and wear tooling after controlled heat treatment | ASTM A681-24 | |
| D2 | Tool | High-carbon high-chromium cold-work tool steel | High-carbon, high-chromium cold-work tool steel emphasizing wear resistance after heat treatment. | Dies, shear blades, punches, and wear tooling after controlled heat treatment | ASTM A681-24 | |
| S7 | Tool | Shock-resisting tool steel | Shock-resisting tool steel for impact-loaded punches, chisels, and tooling. | Impact tooling, punches, chisels, and shear applications after suitable heat treatment | ASTM A681-24 | |
| H13 | Tool | Chromium hot-work tool steel | Chromium hot-work tool steel for die casting, extrusion, forging, and other elevated-temperature tooling. | Die-casting dies, extrusion tooling, and hot-work tooling after controlled heat treatment | ASTM A681-24 | |
| M2 | Tool | Molybdenum high-speed tool steel | Molybdenum high-speed tool steel for drills, taps, milling cutters, and other cutting tools. | Drills, taps, milling cutters, broaches, and other cutting tools after controlled heat treatment | ASTM A681-24 |
SAE 4140
- Steel type
- Chromium-molybdenum
- Identifier basis
- Composition grade
- Key reason it is considered
- Chromium-molybdenum alloy steel with strong heat-treatment response for shafts, gears, axles, and machine parts.
- Typical use
- Heat-treated shafts, gears, axles, and machine components
- What the name establishes
- An SAE chromium-molybdenum alloy-steel composition designation
- Confirm before use
- Product specification, section size, supplied condition, heat treatment, hardness or mechanical requirements, testing, and certification
- Source path
- SAE J404_200901
Important: grade names do not by themselves define every mechanical property, product form, heat treatment, thickness range, test requirement, toughness requirement, finish, weld procedure, or acceptance criterion. Use the focused grade panel and the governing standard to close those gaps.
Compare Selected Steel Grades
Select up to three rows in the chart. The comparison stays descriptive so condition-dependent properties are not presented as false universal values.
Choose a Steel Grade by What You Need
Use this as a shortlist, then verify the exact product standard and condition. The right answer depends on loading, environment, fabrication, section size, heat treatment, inspection, availability, and code requirements.
Structural plate, bars & shapes
Start with: ASTM A36 for common general structural products; ASTM A572 Grade 50 where its HSLA strength level and product scope fit; ASTM A992 for rolled structural shapes used in building framing.
Structural tubing / HSS
Start with: ASTM A500 Grade C when the required cold-formed structural tubing product and project specification align with A500/A500M.
General machined carbon-steel parts
Start with: SAE 1018 or 1020 for low-carbon applications; consider SAE 1045 when a medium-carbon grade and greater heat-treatment response are useful.
Shafts, gears & highly loaded parts
Start with: 1045 for many medium-carbon components; 4140 for Cr-Mo alloy performance after controlled heat treatment; 4340 for more highly loaded applications; 8620 for carburized case-hardened parts.
Corrosion-resistant fabrication
Start with: 304 for broad general stainless use; 316 where its molybdenum-bearing chemistry better fits the reviewed environment; 2205 for duplex-stainless applications; 17-4 PH when high strength plus corrosion resistance is needed after aging.
Dies, punches & cutting tools
Start with: O1, A2, or D2 for cold-work tooling; S7 for shock-loaded tools; H13 for hot-work tooling; M2 for high-speed cutting tools.
Common Steel Grade Comparisons
A36 vs 1018
They are not automatic equivalents. ASTM A36 is a structural product/material specification. SAE 1018 is a carbon-steel composition designation. Compare the exact product form, chemistry requirements, mechanical requirements, dimensions, condition, testing, and certification before considering a substitution.
1018 vs 1045 vs 4140
1018: low-carbon starting point for general parts. 1045: medium-carbon grade when more strength/hardness potential is needed. 4140: Cr-Mo alloy grade used when heat treatment, section size, and higher-duty service justify the alloy choice. Final properties depend on the supplied and heat-treated condition.
304 vs 316 stainless steel
Both are austenitic stainless types. 316 is molybdenum-bearing and is commonly evaluated for more demanding corrosion or chloride-bearing exposure. Neither grade name alone proves suitability for a specific chemical, chloride level, temperature, finish, weld condition, or product form.
A2 vs D2 vs S7 tool steel
A2 is an air-hardening cold-work type often chosen for a balance of wear resistance and dimensional stability. D2 emphasizes wear resistance. S7 is a shock-resisting type for impact-loaded tooling. Heat treatment and target hardness are essential parts of the selection.
A36 vs A572 Grade 50 vs A992
These are structural specifications with different scopes and requirements. A36 covers common structural shapes, plates, and bars; A572 includes HSLA structural grades including Grade 50; A992 covers rolled structural shapes. Do not choose solely from a strength shorthand—confirm product form, thickness, project requirements, welding, toughness, and certification.
What Steel Grade Numbers Mean
SAE carbon and alloy steel numbers
For familiar four-digit SAE carbon and alloy steel designations, the leading digits identify the broad carbon or alloy family and the final two digits conventionally correspond to approximate nominal carbon content in hundredths of a percent. For example, 4140 is an SAE chromium-molybdenum alloy-steel designation. The number does not establish the final heat-treated strength, hardness, section-size response, product form, or purchase specification.
Terminology note: “AISI 4140” and similar AISI/SAE wording remains common in industry and search, but SAE states that AISI is no longer issuing steel grade designations; the grades in SAE J403 and J404 are SAE grades.
ASTM, stainless, and tool-steel identifiers
An ASTM designation such as A36 or A992 points to a product/material specification with a defined scope. A stainless type such as 304 or 316 identifies a familiar alloy type but still needs the applicable product specification and form. Tool-steel names such as A2, D2, S7, H13, and M2 identify tool-steel types whose final properties depend strongly on processing and heat treatment.
Why One Strength or Hardness Number Can Mislead
Searchers often want yield strength, tensile strength, hardness, machinability, or weldability beside every grade. Those values are useful only when their condition is clear. A single universal number beside “4140,” “410,” “17-4 PH,” or “D2” can be misleading because properties can change materially with product specification, section size, delivery condition, heat treatment, test orientation, and whether a published value is a required minimum or a typical value.
| Layer | What it tells you | What still needs confirmation |
|---|---|---|
| Grade / type | Composition family, alloy type, or grade identity. | Product form, condition, dimensions, testing, and final properties. |
| Product specification | Scope and requirements for the supplied product. | Project-specific or service-specific supplementary requirements. |
| Form & size | Plate, sheet, bar, tubing, shape, forging, or other product plus dimensions. | Heat treatment, finish, inspection, and service suitability. |
| Condition & processing | Hot rolled, cold finished, annealed, normalized, quenched and tempered, aged, or another condition. | The complete acceptance criteria and fitness for the actual application. |
For structural design context beyond grade identification, see steel materials and engineering design.
Before Substituting One Steel Grade for Another
- Compare the complete chemistry and product-specification requirements—not only the grade name.
- Compare required yield, tensile, hardness, toughness, fatigue, wear, or corrosion performance in the actual condition and size range.
- Verify product form, dimensions, tolerances, finish, manufacturing route, and delivery condition.
- Verify heat treatment, weld procedure, post-weld requirements, inspection, testing, and material certification.
- Check the active standard edition plus project, customer, code, and authority requirements.
Do not treat a cross-reference as approval. A similar designation in ASTM, SAE, EN, DIN, JIS, or another system is a comparison starting point. It is not automatic evidence of interchangeability.
Engineering Sources and Scope
Turn2Engineering curated 26-grade reference — source check updated October 6, 2026.
This page uses official standards metadata and public scope information plus original explanatory summaries. It does not reproduce proprietary standards tables or present condition-dependent mechanical-property values as universal grade properties.
- SAE J403_202402 — Chemical Compositions of SAE Carbon SteelsStabilized February 2024; source basis for the SAE carbon-steel designations in this chart.
- SAE J404_200901 — Chemical Compositions of SAE Alloy SteelsSource basis for common SAE alloy-steel designations including 4130, 4140, 4340, and 8620.
- ASTM A36/A36M-19, ASTM A572/A572M-25, ASTM A992/A992M-22, and ASTM A500/A500M-23Active structural product specifications used to define the structural rows and their product scopes.
- ASTM A240/A240M-26Active specification for chromium and chromium-nickel stainless plate, sheet, and strip; used here as a product-form source path for the listed stainless types.
- ASTM A693-24 and ASTM A564/A564M-25Active precipitation-hardening stainless product specifications relevant to 17-4 PH / Type 630 depending on product form.
- ASTM A681-24 — Standard Specification for Tool Steels AlloyActive wrought alloy tool-steel specification supporting the O1, A2, D2, S7, H13, and M2 tool-steel rows.
Steel Grades Chart FAQ
The 41xx series identifies a chromium-molybdenum alloy-steel family, while the final two digits conventionally correspond to approximate nominal carbon content in hundredths of a percent. The designation does not define final heat-treated strength or hardness.
No. ASTM A36 is a structural product/material specification, while SAE 1018 is a carbon-steel composition designation. They are not automatic equivalents.
1018 is a low-carbon SAE grade, 1045 is a medium-carbon SAE grade, and 4140 is a chromium-molybdenum alloy grade. That changes the available processing and property range, but the final comparison must use the actual product form, condition, section size, heat treatment, and required properties.
Both are austenitic stainless types. 316 is molybdenum-bearing and is commonly evaluated for more demanding corrosion or chloride-bearing environments. Service suitability still depends on the exact environment, temperature, finish, product form, fabrication, and governing specification.
There is no single strongest grade independent of condition. Yield, tensile, hardness, fatigue, toughness, and other properties depend on alloy, product specification, section size, processing, heat treatment, and the governing test requirements.
“AISI 4140” remains common industry wording, but SAE J404 states that AISI is no longer issuing steel grade designations and that the listed grades are SAE grades. This chart therefore uses SAE 4140 while retaining AISI terminology in search matching.
Only after checking the full chemistry, mechanical requirements, form, dimensions, condition, heat treatment, testing, certification, active standard editions, and project acceptance criteria. A cross-reference is not automatic substitution approval.