{"id":9438,"date":"2025-08-03T16:17:49","date_gmt":"2025-08-03T08:17:49","guid":{"rendered":"https:\/\/aobosteel.com\/?page_id=9438"},"modified":"2026-04-27T07:26:10","modified_gmt":"2026-04-26T23:26:10","slug":"s1-tool-steel","status":"publish","type":"page","link":"https:\/\/aobosteel.com\/ko\/s1-tool-steel\/","title":{"rendered":"S1 Tool Steel | 1.2550"},"content":{"rendered":"
\"\"<\/span>
\n
\n
Home<\/mark> <\/a>> Tool Steel Catalog<\/mark> <\/u><\/a>> S1 Tool Steel<\/h6><\/div>\n\n\n\n
Aobo Steel | Global Tool Steel Supplier in China<\/em><\/h5><\/div>\n\n\n\n

AISI S1 Tool Steel | 1.2550 | SKS41 Chromium-Tungsten Shock-Resisting Steel<\/h2><\/div>\n\n\n\n
\u2713100% UT Tested Quality Assurance<\/h5><\/div>\n\n\n\n
\u2713SEP 1921-82 Class D\/d Guaranteed<\/h5><\/div>\n\n\n\n
\u2713Annealed State Delivery<\/h5><\/div>\n\n\n\n
\u2713Surface: Black Scale, Turned, Mill Finish, or Polished<\/h5><\/div>\n\n\n\n
\n
Quick Inquiry For S1 Material<\/a><\/div>\n<\/div>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n
\n

S1 tool steel is a shock-resisting material. Its primary characteristic is exceptional toughness, which makes it highly resistant to impact loading. Understanding its properties helps determine if it fits your manufacturing needs correctly.<\/p>\n\n\n\n

1. Chemical Composition<\/h2>\n\n\n\n

The typical chemical composition (weight %) for S1 steel falls within these ranges:<\/p>\n\n\n\n

C<\/td>W<\/td>Cr<\/td>Si<\/td>V<\/td>Mn<\/td>Mo<\/td>P<\/td>S<\/td><\/tr>
0.40 – 0.55%<\/td>1.50 – 3.00%<\/td>1.00 – 1.80%<\/td>0.15 – 1.20%<\/td>0.15 – 0.30%<\/td>0.10 – 0.40%<\/td>up to 0.50%<\/td>\u2264 0.030%<\/td>\u2264 0.030%<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

2. S1 Tool Steel Properties<\/h2>\n\n\n\n

Understanding these S1 steel properties will help you determine its suitability for your specific factory applications:<\/p>\n\n\n\n

2.1 Hardness<\/h3>\n\n\n\n

S1 tool steel can achieve a hardness of 40-63 HRC after heat treatment<\/em>. However, for most practical applications requiring its signature shock resistance, S1 is typically used in a working hardness range of 50-56 HRC<\/strong>, often around 55 HRC. It\u2019s important to remember that while higher hardness improves wear<\/em> resistance, it generally reduces toughness.<\/p>\n\n\n\n

2.2 Heat Treatment Response<\/h3>\n\n\n\n

S1 is an oil-hardening steel, capable of reaching its required hardness through oil quenching<\/em>. For simpler or larger cross-sections, water or brine quenching may also be viable options. It exhibits a medium depth of hardening.<\/p>\n\n\n\n

Post-hardening and tempering<\/em> are critical steps.<\/span> While a low tempering temperature (around 300\u00b0C \/ 570\u00b0F) yields maximum hardness, S1 offers a broad usable tempering range from approximately 175\u00b0C to 540\u00b0C (350\u00b0F to 1000\u00b0F). Compared with steels with higher alloy content, S1 tool steel will exhibit a more pronounced decrease in hardness as tempering temperature increases. Be aware that tempering below 315\u00b0C (600\u00b0F) can increase the steel’s notch sensitivity.<\/p>\n\n\n\n

2.3 Toughness and Shock Resistance<\/h3>\n\n\n\n

This is where S1 tool steel truly excels. It has very high, often the highest, toughness among tool steels, particularly when compared to many cold-worked grades. This exceptional toughness, a core property of S1 steel, makes it ideal for applications involving repeated impacts, mechanical shocks, or sudden loads. The medium carbon content, combined with silicon and tungsten additions, is key to this characteristic.<\/p>\n\n\n\n

2.4 Wear Resistance<\/h3>\n\n\n\n

S1 tool steel offers medium to low wear resistance. This is generally lower than cold-work tool steels, such as D2<\/a><\/em> or A2<\/a><\/em>. The tungsten content does contribute some inherent wear resistance. For applications requiring enhanced surface wear resistance, nitriding can be considered. However, this process requires careful management, as the temperatures involved might reduce the core hardness and strength, potentially leading to plastic deformation in high-stress areas if not properly controlled.<\/p>\n\n\n\n

2.5 Hot Hardness and Heat Resistance<\/h3>\n\n\n\n

S1 tool steel possesses low to medium hot hardness<\/strong>. It doesn\u2019t maintain its hardness at elevated temperatures as effectively as high-speed steels. Nevertheless, thanks in part to its tungsten content, it offers a degree of heat resistance, allowing its use in moderately elevated-temperature service or some hot-working applications, generally up to temperatures around 540\u00b0C (1000\u00b0F).<\/p>\n\n\n\n

2.6 Machinability<\/h3>\n\n\n\n

When properly annealed, S1 tool steel is considered to have good machinability<\/strong>. Its rating is often cited as 90-95, compared to a 1% carbon steel standard of 100. Even in the hardened condition, machinability is considered fairly good. The machinability of S1 steel can be further improved by increasing the sulfur content.<\/p>\n\n\n\n

2.7 Dimensional Stability<\/h3>\n\n\n\n

Oil quenching, the typical method for S1, generally results in small and predictable dimensional changes<\/strong>. While air-hardening steels like S7 offer superior dimensional stability, the dimensional stability performance of S1 tool steel is considered good in oil- or water-hardening grades. Water quenching causes severe thermal shock to S1 tool steel, increasing the risk of cracking and deformation, so it should be used with caution.<\/p>\n\n\n\n

\n
\n
\"S1<\/figure>\n<\/div>\n\n\n\n
\n

Interested in S1 Tool steel?<\/strong> Please fill out the following form to contact us for the most competitive S1 tool steel!<\/strong><\/p>\n\n\n\n

\n\t\t\t\t\t\t