Introduction to AISI H13 Flat Wire & Straight Bar
AISI H13 (DIN 1.2344 / JIS SKD61) flat wire and straight bar is a precision-profiled hot-work tool steel product engineered for applications demanding exceptional thermal fatigue resistance. Delivered exclusively in the soft annealed condition with a maximum hardness of 235 HBW, this material offers optimal machinability and predictable heat treatment response. The controlled 5% chromium base, balanced with molybdenum and vanadium, ensures excellent resistance to heat checking and premature cracking. At FUSHUN METAL, we produce H13 profiles within a strict thickness range of 2–50 mm and width of 10–300 mm. Explore our complete range of premium tool steel grades for demanding industrial applications.
| Standard System | Grade / Designation |
|---|---|
| AISI / ASTM | H13 |
| DIN / EN / ISO | 1.2344 / X40CrMoV5-1 |
| JIS | SKD61 |
| GB/T | 4Cr5MoSiV1 |
| BS | BH13 |
| NF | X40CrMoV5 |
Applications & Product Gallery
This versatile profile is widely utilized in high-stress manufacturing sectors requiring reliable thermal cycling performance. Common applications include hot shear blades, slitter knives for metal processing lines, and die-casting mold inserts. It is also ideal for hot extrusion die segments, precision stamping dies, and forging die trim blades. For related high-temperature alloys, review our heat-resisting steel selection.
Additional use cases cover thermal cycling fixtures, glass molding tooling, and wear-resistant industrial knives operating under repeated thermal shock. The material's consistent spheroidized carbide distribution makes it a preferred choice for high-performance mould steel components requiring tight dimensional stability.
Request a QuoteSpecifications & Execution Standards
Our manufacturing processes strictly adhere to internationally recognized metallurgical specifications. We guarantee full compliance with the following standards for chemical composition, dimensional tolerances, and mechanical testing:
- ASTM A681 Standard Specification for Tool Steel Alloy (Covers H13 flat bars and wire rods)
- DIN EN ISO 4957 Tool Steel Standard (Grade X40CrMoV5-1 / 1.2344)
- JIS G4404 Alloy Tool Steel Standard (Grade SKD61)
- BS 4659 Specification for Tool and Die Steels (Grade BH13)
- GB/T 1299 Alloy Tool Steels (Grade 4Cr5MoSiV1) – Rolled flat bars and precision straight bars
Available Sizes & Delivery Conditions
FUSHUN METAL specializes in H13 flat wire and straight bar within a precise dimensional range. Our mill utilizes a 6,000-ton hydraulic press and GFM radial forging machine to ensure superior internal soundness before precision rolling and drawing.
- Thickness: 2 mm – 50 mm
- Width: 10 mm – 300 mm
- Length/Form: Cut-to-length straight bars (standard 2,000–6,000 mm) or coil form (for thickness ≤8 mm)
Delivery & Minimum Order Quantity
Ready stock covers common flat bar sizes for immediate dispatch, with single-piece orders accepted and delivery within approximately 7 days. Custom rolled or drawn flats typically require a 3-ton MOQ with a 30-day lead time. Small-batch special orders are supported by compact induction furnaces, while large-volume projects utilize 30–60 ton EAF campaigns for rapid turnaround.
Chemical Composition Analysis
| Element | AISI H13 | DIN/EN 1.2344 | JIS SKD61 | GB 4Cr5MoSiV1 |
|---|---|---|---|---|
| C | 0.32–0.45 | 0.37–0.42 | 0.32–0.42 | 0.32–0.45 |
| Si | 0.80–1.20 | 0.80–1.20 | 0.80–1.20 | 0.80–1.20 |
| Mn | 0.20–0.50 | 0.30–0.50 | ≤0.50 | 0.20–0.50 |
| Cr | 4.75–5.50 | 4.80–5.50 | 4.50–5.50 | 4.75–5.50 |
| Mo | 1.10–1.75 | 1.20–1.50 | 1.00–1.50 | 1.10–1.75 |
| V | 0.80–1.20 | 0.90–1.10 | 0.80–1.20 | 0.80–1.20 |
| P | ≤0.030 | ≤0.030 | ≤0.030 | ≤0.030 |
| S | ≤0.030 | ≤0.030 | ≤0.030 | ≤0.030 |
Note: Bold values indicate tighter control ranges per the EN standard. All values represent heat analysis.
Melting Routes & Processing
We match the melting route to your performance requirements and cost targets. Standard H13 flat wire and bars are produced via EAF + LF + VD for reliable cleanliness and uniform composition. For applications requiring superior isotropy and extended thermal fatigue life, we offer ESR or PESR remelting.
For aerospace-grade or mission-critical tooling, VIM + VAR double vacuum melting is available to achieve ultra-low gas content and maximum purity. Our metallurgical engineers will help you select the optimal process route. Contact us to discuss the best melting practice for your project.
Mechanical Properties & Heat Treatment
| Condition | Hardness | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Reduction of Area (%) |
|---|---|---|---|---|---|
| Soft Annealed (Delivery) | ≤235 HBW | ~750 | ~550 | ~18 | ~45 |
| Hardened & Tempered @ 550°C | 50–52 HRC | ~1,950 | ~1,650 | ~10 | ~35 |
| Hardened & Tempered @ 600°C | 46–48 HRC | ~1,750 | ~1,450 | ~12 | ~40 |
Note: Material is supplied strictly in the annealed condition. Hardened values are typical reference data after end-user heat treatment.
Recommended Heat Treatment Cycles
| Process | Temperature Range | Soaking Time | Cooling Method |
|---|---|---|---|
| Soft Annealing | 845–900 °C | 2–4 hours | Furnace cool to ~500 °C, then air |
| Stress Relieving | 650–700 °C | 1–2 hours | Air cool |
| Hardening | 1000–1040 °C | 15–30 min | Vacuum, high-pressure gas, or oil |
| Tempering | 550–650 °C | 2 hours min (×2 or ×3) | Air cool to room temp between cycles |
Preheating at 600–650 °C and 800–850 °C is strongly recommended to minimize thermal shock. Material is delivered fully annealed and ready for your final heat treatment.
Surface Finish & Machining Capabilities
FUSHUN METAL supplies H13 flat wire and straight bar in black surface or precision-machined finishes. Bright rolled or peeled surfaces achieve Ra ≤ 6.3 μm, while precision ground or milled finishes reach Ra ≤ 1.6–3.2 μm. Dimensional tolerances are tightly controlled from ±0.05 mm for thin gauges up to ±0.20 mm for thicker sections.
Straightness is maintained within ≤2 mm/1000 mm, and flatness ≤3 mm/1000 mm for widths over 50 mm. CNC rough machining, edge chamfering, and custom profile milling are available to reduce your secondary processing time. All surfaces are inspected for seams, laps, and decarburization before dispatch.
Quality Assurance & Inspection Protocols
Quality is controlled at every stage of production. Raw materials are strictly vetted before melting, with real-time spectral analysis and temperature monitoring during processing. Every batch undergoes comprehensive post-production inspection, including chemical verification, hardness testing, and metallographic evaluation of carbide spheroidization.
Ultrasonic testing is performed per SEP 1921 Class 3 or ASTM A388, with stricter acceptance levels available upon request. Decarburization depth is limited to ≤1.0% of thickness per side. All shipments include an EN 10204 Type 3.1 certificate, and our system is certified to ISO 9001 and AS9100 standards.
Packing & Shipping Standards
Packaging is engineered for safe ocean freight and handling. Thin-gauge flat wire is tightly coiled, strapped, and mounted on fumigated wooden pallets. Straight bars are securely bundled with high-tensile steel wire or individually crated to prevent edge damage and bending during transit.
Bright-finished or ground products are wrapped in VCI paper or protective film to preserve surface roughness. All materials are coated with industrial-grade anti-rust oil before packing, guaranteeing zero corrosion during long-distance shipping. Custom heat-number tagging and container blocking are standard.
Frequently Asked Questions
Is the H13 flat bar supplied ready for machining, or does it require stress relieving first?
The material is delivered fully soft annealed (≤235 HBW) with a uniform spheroidized carbide structure, making it immediately ready for milling, drilling, or turning. For heavy stock removal, we recommend a mild stress-relieving cycle after rough machining.
Can you cut the straight bars to my exact length, and what tolerance can you hold?
Yes. We offer precision saw cutting and CNC milling to your specified lengths. Standard saw cuts hold ±3 mm tolerance, while precision machined cuts can be held within ±0.5–1.0 mm, reducing material waste.
How do you control decarburization on the flat wire and bar edges?
Decarburization is strictly managed through controlled-atmosphere annealing and precision rolling. For ground finishes, the decarb layer is completely removed. For black surface material, total decarburization is limited to ≤1.0% of thickness per side.
Do you supply this product in coil form for automated feeding?
Yes. For thicknesses between 2–8 mm, we supply H13 flat wire in tightly wound coils with consistent camber control, suitable for automated stamping. Contact us with your coil weight and diameter requirements.
