Purohit Steel is a leading Grade S1 / 1.2550 Stockist and Exporter in India, supplying premium shock-resisting tool steel with verified chemical composition, mechanical properties and full traceability for tool rooms, forging shops and manufacturers of impact tools.
As an ISO-certified company established in 1965, we maintain ready stock of Grade S1 / 1.2550 in round bar and flat bar form, with in-house bandsaw cutting, machining, grinding and EDM support for fast turnaround across India and export markets.
Table of Contents
- 1. What is Grade S1 / 1.2550 Steel
- 2. Why Purohit Steel for S1
- 3. Comparison: S1 vs S7 vs O1
- 4. Chemical Composition
- 5. Mechanical Properties
- 6. Physical & Thermal Properties
- 7. Equivalent International Grades
- 8. Heat Treatment Guidelines
- 9. Available Forms & Sizes
- 10. Machining & Selection Notes
- 11. Applications & Uses
- 12. Industries We Serve
- 13. Related Products
- 14. Authorized Stockist Brands
- 15. Cities We Supply in India
- 16. Our Services
- 17. Frequently Asked Questions
- 18. About Purohit Steel
- Our Certifications
- Countries We Export Worldwide
- Export Packaging & Shipping
- Quality Inspection & Testing
- Latest Price List
- MOQ & Payment Terms
- People Also Search For
What is Grade S1 / 1.2550 Steel?
Grade S1 (DIN Werkstoffnummer 1.2550, chemical designation 60WCrV8) is an oil-hardening, tungsten-chromium-vanadium shock-resisting tool steel manufactured to DIN EN ISO 4957. It belongs to the ASTM S-series of shock-resisting grades, developed specifically for tools subjected to repeated impact and shock loading rather than continuous abrasive wear.
S1 combines good hardenability with excellent toughness and dimensional stability. The tungsten content contributes to wear resistance and helps the steel resist softening, while the silicon content promotes a microstructure resistant to distortion in the tempered condition. After oil hardening and tempering, S1 typically achieves 56-60 HRC while retaining useful ductility.
S1 offers a very broad usable tempering range (roughly 175-540°C), letting toolmakers dial in the exact balance of hardness and shock resistance the application needs — see the comparison table below for how it compares with S7 and O1.
Why Purohit Steel for Grade S1 / 1.2550
- Ready Stock: Round bar and flat bar sizes held in inventory for immediate dispatch
- ISO-Certified Quality: Documented quality management since 1965
- Authorized Stockist: Sourced through globally reputed manufacturers, including NLMK Verona and SeAH CSS
- Value-Added Machining: In-house bandsaw cutting, precision machining, grinding, drilling, gun drilling, EDM and wire-cut
- Technical Support: Assistance with grade selection, heat treatment guidance and equivalence mapping
- Pan-India & Export Supply: Warehousing in Vasai with a sales outlet in Mumbai, serving customers across India and international markets
- Export-Ready Packaging: Palletised, moisture-protected packing suitable for both domestic transport and export shipment
Comparison: S1 vs S7 vs O1
Buyers often need to choose between related shock-resisting and general-purpose cold work grades. The table below compares S1 / 1.2550 against two other grades Purohit Steel stocks, to help select the right material for the application.
| Factor | S1 / 1.2550 | S7 | O1 / 1.2510 |
|---|---|---|---|
| Alloy family | Tungsten-Cr-V, oil-hardening | Cr-Mo, air-hardening | Mn-Cr-W, oil-hardening |
| Working hardness | 56-60 HRC | 54-58 HRC | 57-62 HRC |
| Shock / impact resistance | Excellent | Best in class among cold work grades | Moderate |
| Hardenability / distortion in heat treatment | Good, oil quench needed | Excellent, air-hardening minimises distortion | Good for thin/medium sections, oil quench |
| Wear resistance | Moderate | Good | Good, better edge holding than S1/S7 |
| Best suited for | Chisels, hammers, punches, riveting tools | Larger punches, dies and precision tooling under heavy shock | General-purpose gauges, blanking & forming dies, cutting tools |
Grade S1 / 1.2550 Chemical Composition
Composition as per DIN EN ISO 4957 (typical mill range, weight %):
| Element | Symbol | Composition (%) |
|---|---|---|
| Carbon | C | 0.55 - 0.65 |
| Silicon | Si | 0.70 - 1.00 |
| Manganese | Mn | 0.15 - 0.45 |
| Chromium | Cr | 0.90 - 1.20 |
| Tungsten | W | 1.70 - 2.20 |
| Vanadium | V | 0.10 - 0.20 |
| Phosphorus | P | 0.030 max |
| Sulphur | S | 0.030 max |
| Iron | Fe | Balance |
Mechanical Properties of Grade S1 / 1.2550
Typical values; supplied soft-annealed and hardened by the customer or on request:
| Property | Typical Value |
|---|---|
| Supply hardness (annealed) | ≤229 HB |
| Hardness (hardened & tempered) | 56 - 60 HRC (usable range 40-63 HRC depending on temper) |
| Shock / Impact Resistance | Excellent |
| Toughness | Very good, with good ductility retained at working hardness |
| Wear Resistance | Moderate |
| Dimensional Stability | Good, aided by silicon content |
| Corrosion Resistance | Low |
| Modulus of Elasticity (E) | ~210 GPa |
Values are typical and vary with section size, tempering temperature and mill batch. Mill test certificates (EN 10204 2.2 / 3.1) are available on request.
Physical & Thermal Properties
| Property | Value |
|---|---|
| Density | ~7.85 g/cm³ |
| Thermal Conductivity (room temp.) | ~29-33 W/(m·K) |
| Coefficient of Thermal Expansion (20-200°C) | ~12 × 10-6 /K |
| Specific Heat Capacity | ~460 J/(kg·K) |
| Modulus of Elasticity | ~210 GPa |
Equivalent International Grades
| Country / Standard | Designation |
|---|---|
| Germany (Werkstoffnummer, DIN EN ISO 4957) | 1.2550 / 60WCrV8 |
| USA (AISI / SAE, ASTM A681) | S1 |
| USA (UNS) | T41901 |
S1 is part of the shock-resisting S-series alongside S7 — refer to the comparison table above before substituting grades.
Heat Treatment Guidelines
| Process | Guideline |
|---|---|
| Supply condition | Soft-annealed, ≤229 HB — ready to machine before hardening |
| Preheating (larger / intricate tools) | 650-700°C |
| Hardening (austenitizing) | Raise quickly to 900-950°C, hold to equalise |
| Quenching | Oil or salt bath, quench to approx. 52-65°C |
| Tempering | 175-540°C depending on target hardness; typically 1 hr at ~230°C for standard use, up to 540-650°C for maximum toughness; soak 2 hrs per 25 mm section, air cool |
| Resulting hardness range | Approx. 40-63 HRC depending on tempering temperature; working range typically 56-60 HRC |
Available Forms & Sizes
- Round Bars
- Flat Bars
- Custom sizes cut to drawing via in-house bandsaw cutting
Material is machined, ground, drilled and finished in-house through our precision machining, grinding, drilling, gun drilling, EDM and wire-cut facilities.
Machining & Selection Notes
- Machinability: S1 machines well in the annealed condition using standard HSS or carbide tooling.
- Tempering for application: Use a lower tempering temperature (~175-230°C) for maximum hardness where wear matters more, or a higher temper (up to ~540°C) where toughness against repeated impact is the priority.
- Quenching: Oil-quench promptly and uniformly to reduce distortion risk in larger sections; salt bath quenching can further improve dimensional control.
- Welding / repair: Limited weldability; preheat and stress-relieve after any weld repair.
- Grade selection: Choose S1 for hand and pneumatic impact tools such as chisels and punches; step up to S7 for larger, air-hardening tooling with the highest available shock resistance, or choose O1 where wear resistance and edge holding matter more than shock resistance — see the comparison table above.
Applications of Grade S1 / 1.2550 Steel
S1 / 1.2550 is used wherever tools must absorb repeated impact without cracking or chipping, across forging, construction and heavy manufacturing industries.
- Hot and cold chisels
- Hammers and sledgehammer tools
- Punches and drift tools
- Hot forging dies
- Riveting and boiler tools
- Cold headers and upsetter tools
- Heavy-duty woodworking tools
- Shear blades for shock applications
Hand & Pneumatic Tools
S1's combination of high hardness and retained ductility makes it well suited to chisels, punches and pneumatic tool bits that see continuous, repeated striking in service.
Forging Industry
S1's thermal shock resistance and toughness make it suitable for hot forging dies and tools exposed to cyclic heating and cooling in addition to mechanical impact.
Industries We Serve
- Forging industry
- Tool room industry
- Construction & heavy engineering
- Automotive component manufacturing
- Mould and die manufacturing
- General engineering & industrial manufacturing
Authorized Stockist
Grade S1 / 1.2550 Supply Locations Across India
We supply Grade S1 / 1.2550 steel across major industrial cities including Mumbai, Pune, Khopoli, Nashik, Aurangabad, Navi Mumbai, Palghar, Umbergaon, Vapi, Valsad, Daman, Vadodara, Ahmedabad, Rajkot, Hyderabad, Bangalore, Chennai, Cochin, Delhi, Gurgaon, Manesar and Sonipat — as well as to export markets.
Our Steel Products
Our Services
Frequently Asked Questions
About Purohit Steel
Purohit Steel was established in 1965 by Shree Bherumalji Rajpurohit, a visionary in metallurgy. Over the decades, we have built a strong reputation as a trusted stockist and exporter of tool steel, plastic mould steel and engineering steel products across India.
As an ISO-certified company, we source premium materials from globally reputed manufacturers and operate a modern warehousing facility in Vasai along with a sales outlet in Mumbai, enabling efficient storage, fast processing and timely delivery across India and export markets.
With decades of relationships with tool & die manufacturers and a customer-focused approach, Purohit Steel continues to deliver reliable, technically supported steel solutions for the tooling industry.
Read more about Purohit Steel, view our certifications, or get in touch with our technical sales team.
Our Certifications
Purohit Steel operates as an ISO-certified company, backed by documented quality management, safety and compliance certifications that support reliable supply to domestic and export customers.
View all certificates in detail on our Certifications page.
Countries We Export Worldwide
Beyond India, Purohit Steel exports tool & mould steel grades to customers across the following countries and regions:
| Export Destinations | |||||
|---|---|---|---|---|---|
| UAE | Saudi Arabia | Oman | Bangladesh | Sri Lanka | Nepal |
| Vietnam | Thailand | Indonesia | Kenya | Nigeria | South Africa |
For export enquiries and destination-specific documentation, please contact our sales team.
Export Packaging & Shipping
Bars, flats and blocks are packed to withstand handling, transit and marine shipment, whether for domestic dispatch or export orders.
- Palletised and strapped packing for round bars, flat bars and blocks
- Moisture-protected wrapping to prevent surface corrosion in transit
- Seaworthy export packing with clear shipping marks and material identification
- Documentation support including packing lists, invoices and mill test certificates for customs clearance
- Shipment by road, rail or sea freight as per order requirement and destination
Quality Inspection & Testing
Every batch held in our stock is checked through documented inspection procedures before dispatch, so mould makers and OEMs receive material with verified, traceable quality.
- Chemical composition verification against mill certificates
- Hardness testing (Brinell / Rockwell) on received stock
- Dimensional inspection as per standard bar and block tolerances
- Visual and surface defect inspection
- EN 10204 2.2 / 3.1 mill test certificates provided on request
- Third-party inspection coordination available for export orders
Full material traceability is maintained from incoming stock through to dispatch for every order.
Latest Price List
Pricing depends on section size, quantity, form (round bar / flat bar / block) and current raw material rates. Indicative guidance is below — contact us for a firm, up-to-date quotation.
| Form | Typical Price Basis |
|---|---|
| Round Bar | Per Kg, based on diameter & length — contact for latest rate |
| Flat Bar / Plate | Per Kg, based on thickness & size — contact for latest rate |
| Block (cut to size) | Per Kg / Per Piece, based on drawing — contact for latest rate |
Prices are subject to change with raw material and freight costs. Share your required size and quantity via the quotation form or WhatsApp for the latest price.
MOQ & Payment Terms
Minimum Order Quantity: Flexible MOQ depending on size and form — from small trial quantities for tooling houses up to bulk orders for OEMs, subject to confirmation at enquiry stage.
Payment Terms: Advance payment / part-advance with balance before dispatch for domestic orders; T/T (bank transfer) or Letter of Credit (LC) for export orders, depending on order value and destination.