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![Unalloyed tool steels / carbon steels](/images/uploads/e326f3cd-d9d9-4155-80b5-45a6015cd088/unalloyed-tool-steels-carbon-steels-category-hand-tool-stock-1920x1080.jpg)

Category · 35 grades

# Unalloyed tool steels / carbon steels

Unalloyed tool steels are carbon steels whose working properties are developed primarily through carbon content and heat treatment. They are characterised by high attainable hardness and wear resistance, and are used for cutting tools, punches, dies, gauges and other tooling where edge retention and resistance to deformation are important.

| Grade | Material no. | C | Si | P | S | Mn | Cr |
|---|---|---|---|---|---|---|---|
| [SK90](/materials/jis/sk90 "SK90") | — | 0.85 - 0.95 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC140](/materials/ks/stc140 "STC140") | — | 1.3 - 1.5 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC90](/materials/ks/stc90 "STC90") | — | 0.85 - 0.95 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC70](/materials/ks/stc70 "STC70") | — | 0.65 - 0.75 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK95](/materials/jis/sk95 "SK95") | — | 0.9 - 1 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK60](/materials/jis/sk60 "SK60") | — | 0.55 - 0.65 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC95](/materials/ks/stc95 "STC95") | — | 0.9 - 1 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC75](/materials/ks/stc75 "STC75") | — | 0.7 - 0.8 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK120](/materials/jis/sk120 "SK120") | — | 1.15 - 1.25 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK70](/materials/jis/sk70 "SK70") | — | 0.65 - 0.75 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC105](/materials/ks/stc105 "STC105") | — | 1 - 1.1 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC80](/materials/ks/stc80 "STC80") | — | 0.75 - 0.85 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC60](/materials/ks/stc60 "STC60") | — | 0.55 - 0.65 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK140](/materials/jis/sk140 "SK140") | — | 1.3 - 1.5 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [SK80](/materials/jis/sk80 "SK80") | — | 0.75 - 0.85 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC120](/materials/ks/stc120 "STC120") | — | 1.15 - 1.25 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC85](/materials/ks/stc85 "STC85") | — | 0.8 - 0.9 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [STC65](/materials/ks/stc65 "STC65") | — | 0.6 - 0.7 | 0.1 - 0.35 | max 0.03 | max 0.03 | 0.1 - 0.5 | max 0.3 |
| [1.1620](/materials/material-no/1.1620 "1.1620") | [1.1520](/materials/material-no/1.1520 "1.1520") | 0,65-0,75 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,40 | — |
| [C80U](/materials/din-en/c80u "C80U") | [1.1525](/materials/material-no/1.1525 "1.1525") | 0,75-0,85 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,40 | — |
| [C105W2](/materials/din-en/c105w2 "C105W2") | [1.1535](/materials/material-no/1.1535 "1.1535") | 0,85-0,95 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,40 | — |
| [1.1545](/materials/material-no/1.1545 "1.1545") | [1.1545](/materials/material-no/1.1545 "1.1545") | 1,00-1,10 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,40 | — |
| [C110U](/materials/din-en/c110u "C110U") | [1.1554](/materials/material-no/1.1554 "1.1554") | 1,00-1,10 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C110W1](/materials/din-en/c110w1 "C110W1") | [1.1555](/materials/material-no/1.1555 "1.1555") | 1,15-1,25 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,40 | — |
| [C125U](/materials/din-en/c125u "C125U") | [1.1563](/materials/material-no/1.1563 "1.1563") | 1,20-1,35 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C135U](/materials/din-en/c135u "C135U") | [1.1573](/materials/material-no/1.1573 "1.1573") | 1,30-1,45 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C70W2](/materials/din-en/c70w2 "C70W2") | [1.1620](/materials/material-no/1.1620 "1.1620") | 0,65-0,74 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C80W2](/materials/din-en/c80w2 "C80W2") | [1.1625](/materials/material-no/1.1625 "1.1625") | 0,75-0,85 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C105W2](/materials/din-en/c105w2 "C105W2") | [1.1645](/materials/material-no/1.1645 "1.1645") | 1,00-1,10 | 0,10-0,30 | 0,03 | 0,03 | 0,10-0,35 | — |
| [C45U](/materials/din-en/c45u "C45U") | [1.1730](/materials/material-no/1.1730 "1.1730") | 0,42-0,50 | 0,15-0,40 | 0,03 | 0,03 | 0,60-0,80 | — |
| [C60U](/materials/din-en/c60u "C60U") | [1.1740](/materials/material-no/1.1740 "1.1740") | 0,55-0,65 | 0,15-0,40 | 0,035 | 0,035 | 0,60-0,80 | — |
| [C67W](/materials/din-en/c67w "C67W") | [1.1744](/materials/material-no/1.1744 "1.1744") | 0,64-0,72 | 0,15-0,40 | 0,035 | 0,035 | 0,60-0,80 | — |
| [C75W](/materials/din-en/c75w "C75W") | [1.1750](/materials/material-no/1.1750 "1.1750") | 0,72-0,82 | 0,15-0,40 | 0,035 | 0,035 | 0,60-0,80 | — |
| [C55W](/materials/din-en/c55w "C55W") | [1.1820](/materials/material-no/1.1820 "1.1820") | 0,50-0,58 | ≤0,15 | 0,03 | 0,03 | 0,30-0,50 | — |
| [C85U](/materials/din-en/c85u "C85U") | [1.1830](/materials/material-no/1.1830 "1.1830") | 0,80-0,90 | 0,25-0,40 | 0,025 | 0,02 | 0,50-0,70 | — |

## Standards covering this category

 22

- [**JIS***18 grades*](/materials/jis "JIS — 18 grades in this category")
- [**DIN / EN***17 grades*](/materials/din-en "DIN / EN — 17 grades in this category")
- [**KS***15 grades*](/materials/ks "KS — 15 grades in this category")
- [**ČSN***13 grades*](/materials/csn "ČSN — 13 grades in this category")
- [**GOST***12 grades*](/materials/gost "GOST — 12 grades in this category")
- [**PN***12 grades*](/materials/pn "PN — 12 grades in this category")
- [**AISI / SAE***11 grades*](/materials/aisi-sae "AISI / SAE — 11 grades in this category")
- [**AFNOR***11 grades*](/materials/afnor "AFNOR — 11 grades in this category")
- [**UNI***11 grades*](/materials/uni "UNI — 11 grades in this category")
- [**ISO***9 grades*](/materials/iso "ISO — 9 grades in this category")
- [**GB***9 grades*](/materials/gb "GB — 9 grades in this category")
- [**ÖNORM***9 grades*](/materials/onorm "ÖNORM — 9 grades in this category")
- [**UNS***8 grades*](/materials/uns "UNS — 8 grades in this category")
- [**BS***8 grades*](/materials/bs "BS — 8 grades in this category")
- [**UNE***7 grades*](/materials/une "UNE — 7 grades in this category")
- [**MSZ***7 grades*](/materials/msz "MSZ — 7 grades in this category")
- [**STAS***7 grades*](/materials/stas "STAS — 7 grades in this category")
- [**BDS***7 grades*](/materials/bds "BDS — 7 grades in this category")
- [**SRPS***6 grades*](/materials/srps "SRPS — 6 grades in this category")
- [**STN***5 grades*](/materials/stn "STN — 5 grades in this category")
- [**SS***3 grades*](/materials/ss "SS — 3 grades in this category")
- [**ASTM***2 grades*](/materials/astm "ASTM — 2 grades in this category")

## Property ranges

 16

| Property | Unit | Min | Max | Grades |
|---|---|---|---|---|
| Rm | N/mm² | 410 | 1420 | 6 |
| Re | N/mm² | 325 | 1230 | 3 |
| A5 | % | 10 | 28 | 5 |
| Z | % | 34 | 50 | 3 |
| KCU | kJ/m² | 270 | 270 | 1 |
| HB | — | 183 | 217 | 26 |
| HRC | — | 55 | 63 | 10 |
| rho | g/cm³ | 7.489 | 7.852 | 17 |
| E | GPa | 166 | 209 | 2 |
| alpha | 10^-6/K | 10.5 | 16.8 | 3 |
| lambda | W/(m·K) | 24 | 49 | 4 |
| cp | J/(kg·K) | 469 | 970 | 3 |
| rho\_el | nΩ·m | 130 | 1196 | 4 |
| Ac1 | °C | 720 | 730 | 5 |
| Ac3 | °C | 770 | 830 | 4 |
| Ar1 | °C | 700 | 700 | 5 |

Derived from 26 grades in this category with a recorded value.

## Composition range

 8

| Property | Unit | Min | Max | Grades |
|---|---|---|---|---|
| C | % | 0.42 | 1.5 | 35 |
| Si | % | 0.1 | 0.4 | 35 |
| P | % | 0.025 | 0.035 | 35 |
| S | % | 0.02 | 0.035 | 35 |
| Cr | % | 0.3 | 0.3 | 18 |
| Mn | % | 0.1 | 0.8 | 35 |
| Ni | % | 0.25 | 0.25 | 18 |
| Cu | % | 0.25 | 0.25 | 18 |

Derived from 35 grades in this category with a recorded value.

## Related guides

 3

- [**Carbon, Alloy, Stainless, and Tool Steel: How the Categories Overlap**](/wiki/steel-families/carbon-alloy-stainless-and-tool-steel "Carbon, Alloy, Stainless, and Tool Steel: How the Categories Overlap")
- [**Tool Steels: Classification, Properties, and Applications**](/wiki/steel-families/tool-steels-classification-properties-and-applications "Tool Steels: Classification, Properties, and Applications")
- [**Carbon Equivalent Calculations for Welding**](/wiki/calculated-values/carbon-equivalent-calculations "Carbon Equivalent Calculations for Welding")