SPECIAL Hot Work Tool Steel CS1
CS1 tool steel with ultra-clean microstructure offers superior toughness, excellent thermal fatigue resistance and high temper stability. It is widely used for drop forging, hot forming and extrusion dies.
- Standard: CS1 Kind&Co
- Technique: Forged
- Shape: Block
- Heat treatment: Annealed / Q+T
- Surface Treatment: Black, Machined
- Tolerance: +/- 1%
- MOQ: 1
We supply CS1 in various custom sizes

block size range
- Thickness: ≤700 mm
- Width: ≤1200 mm
Chemical Composition (%)
Grade | C | Si | Mn | Cr | Mo | V |
CS1 | 0.5 | 0.30 | 0.40 | 5.0 | 1.90 | 0.55 |
Main characteristics of CS1 tool steel
- Ultra-clean microstructure – prolongs die service life
- Balanced hardness & toughness – withstands thermal shock
- Superior thermal fatigue resistance – minimizes heat cracking
- High temper stability – stable at high temperatures
CS1 tool steel applications
CS1 steel For Drop forging
CS1 features pure uniform structure and great impact toughness, coping with frequent heavy blows to cut die replacement costs in drop forging operations.
CS1 steel For Hot forming
This steel balances thermal stability and crack resistance, holding steady precision under cyclic high heat during all hot forming manufacturing processes.
CS1 steel for Extrusion presses
With outstanding hot hardness and anti-heat-check performance, it endures sustained high pressure heat cycles for long-lasting extrusion production.
Our production technology for CS1 KIND&CO Die Steel
- Melting
- Forging
- Hardening & Annealing
- Finishing
- Stock & Sawing
- Machining
- Vacuum Hardening
- UT 100% SEP1921 Class 3 D/d or E/e
- Spheroidized microstructure as per standard NADCA207-2003 AS1-AS9
- Macrostructure, microstructure, grain size, and impact toughness shall meet the standards specified in GB/T 1299-2025 for Tool and Die Steels.
mechanical properties & heat treatment of CS1 steel
| Heat temperature | Start forging temperature | Finish forging temperature | Cooling method |
| 1120-1150 °c | 1050-1100 °c | 900-850 °c | Pit or sand cooling |
Annealing
- Temperature 820-840℃,4-6 hrs.
- Cooling Slow furnace cooling
- Hardness max. 230 HB
Hardening
- Temperature 1010-1040℃
-
Cooling Air, warm bath of approx.540℃,Oi/polymer;
Interrupt oil or polymer cooling at 230-280℃ or vacuum hardening
Recommendations
- Nitriding possible
- Preheating before use Temperature 150-350℃ according to application
Tempering
- Temperature 540-680℃
- Hardness see tempering curve
Why Choose NSPM as Your CS1 Tool Steel Supplier
Source Direct
Direct mill cooperation ensures stable supply, competitive pricing, and consistent quality. Global resource integration and strong supply chain management guarantee reliable material sourcing and long-term availability.
Stock Ready
50,000+ tons inventory across 11 warehouses enables fast delivery. Flexible cutting, short lead times, and ready stock support urgent demands and improve customers’ production efficiency.
Expert Team
600+ professionals, including R&D specialists and technical engineers, provide application-driven support. Fast response and deep tooling knowledge ensure accurate solutions for diverse industrial needs.
Fully Inspected
Strict quality control system with full traceability, UT testing, and heat treatment records. Certified standards (ISO, CE) ensure every material meets high-performance and reliability requirements.
Full-Chain Machining
From steel supply to precision machining, heat treatment, and equipment manufacturing, NSPM offers integrated solutions that enhance accuracy, efficiency, and overall tooling performance.