Sichuan Liaofu Special Steel Company is one of the most experienced manufacturers and suppliers of s2 tool steel in China. With over 20 years' experience, our factory offer high quality products made in China with competitive price. Welcome to contact us for wholesale service.
After several years of development, Sichuan Liaofu Special Steel Industry Co., Ltd mainly produce die steel, high alloy steel smelting, refining, forging, machining, heat treatment of high-quality goods, and formed complete production management system, our company is a private enterprise, the hometown of abrasive tool steel production in China - hubei,
S2 is a class of tool steels designed to resist breakage by shock. Under the AISI classification system there are seven types, labeled S1 to S7.
S2 is always used to produce screwdriver with hex size 6.35mm
Overview
Shock-resisting steels are designed to have high impact resistance (toughness), along with other properties such as strength, hardness. Silicon is a common addition to this class of steels, as it provides tempering resistance and increases toughness.[1]
Applications for shock-resisting steels includes springs, as well as chisels, dies for forging, and punches.[1] S2 steel is also used to make ball bearings for the mining industry.[2] They are also used for screwdrivers and driver bits.[3]
S2 tool steel chemical composition:
| Type | C % | Si % | V % | Cr % | Mn % | Ni % | Mo % | W % |
|---|---|---|---|---|---|---|---|---|
| S1 (UNS T41901) | 0.40–0.55 | 0.15–1.20 | 0.15–0.30 | 1.00–1.80 | 0.10–0.40 | <0.30 | <0.50 | 1.50–3.00 |
| S2 (UNS T41902) | 0.40–0.55 | 0.90–1.20 | <0.50 | - | 0.30–0.50 | <0.30 | 0.30–0.60 | - |
| S3[4] | 0.50 | 2.00 | - | 0.74 | - | - | - | 1.00 |
| S4 (UNS T41904) | ? ~0.4–0.65 | 1.75–2.25 | 0.35 | 0.35 | 0.60–0.90 | - | ||
| S5 (UNS T41905) | 0.50–0.65 | 1.75–2.25 | <0.35 | <0.50 | 0.60–1.00 | - | 0.20–1.35 | - |
| S6 (UNS T41906) | 0.40–0.50 | 2.00–2.50 | 0.20–0.40 | 1.20–1.50 | 1.20–1.50 | - | 0.30–0.50 | - |
| S7 (UNS T41907)] | 0.45–0.55 | 0.20–1.00 | 0.20–0.30[b] | 3.00–3.50 | 0.20–0.90 | - | 1.30–1.80 | - |
S2 alloy steel is a shock-resisting tool steel type. It retains good ductility even in hardened conditions, which allows it to perform in applications where shock impact is transmitted to the alloy. Shock-resisting tool steels like this are designated as group S steels.
How strong is S2 alloy steel?
| Physical Properties | Metric | English | Comments |
|---|---|---|---|
| Density | 7.83g/cc | 0.283lb/in³ | |
| Mechanical Properties | Metric | English | Comments |
| Hardness, Knoop | 624 | 624 | Converted from Rockwell C Hardness. |
| Hardness, Rockwell C | 55 | 55 | |
| Hardness, Vickers | 602 | 602 | Converted from Rockwell C Hardness. |
| Tensile Strength, Ultimate | 2150MPa | 312000psi | |
| Tensile Strength, Yield | 2000MPa | 290000psi | |
| Elongation at Break | 7.0 % | 7.0 % | in 50 mm |
| Bulk Modulus | 160GPa | 23200ksi | Typical for steel |
| Shear Modulus | 80.0GPa | 11600ksi | Typical for steel |
some pictures of S2 tool steel
FAQ
Q: Does S2 really hold up for screwdriver bits that get twisted hard every day?
A: Yes – that's exactly what it's made for. The 6.35mm hex size is the common standard, and S2 keeps its ductility even at HRC 55–58, so the tip doesn't snap off under side load. We supply round bars ground to that hex size directly – you just cut and broach.
Q: How does S2 compare to S7 for a cold‑forming punch – which one should I pick?
A: S7 has more chromium and molybdenum (3.0–3.5% Cr, 1.3–1.8% Mo) and better toughness at higher hardness, but S2 is cheaper and easier to machine in the annealed state. For punching mild steel up to 6mm thick, S2 works fine. For thicker or harder stock, step up to S7.
Q: I see the tensile strength listed at 2150MPa – is that real, and can I use S2 for high‑strength bolts?
A: That number is real, but it's for hardened and tempered condition. However, tool steel isn't meant for fasteners – it's brittle at that strength level. Use it for tools, not structural bolts. We sell it to bit makers, not to bolt shops.
Q: How do I estimate the weight of a long S2 bar for shipping cost – do you have a density figure?
A: We use 7.83 g/cc. For a round bar, it's πr² × length × 7.83 ÷ 1000 to get kg per metre. For flat stock, it's width × thickness × length × 7.83. We can also cut to your exact length and weigh each bundle on our floor scale – you pay the actual net weight.
Q: Do you melt and forge this yourself, or are you just a trader?
A: We are a private mill – we do our own smelting, refining, forging, machining, and heat treatment. That means we control the chemistry from the melt to the final bar. If you need a specific heat size or custom profile, we can adjust the forging process rather than just cutting from stock.
Q: Your company is in Sichuan, but the description says Hubei is the hometown of tool steel – where do you actually ship from?
A: Our production base is in Hubei – that's where the forging and heat‑treatment lines are. The Sichuan office handles sales and export. All shipments leave from our Hubei warehouse, near major ports. Lead time to Shanghai is about 3 days by truck, then onto container vessels.
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