8407 vs H13 – Composition, Heat Treatment, Properties, and Applications

Introduction

Engineers, procurement managers, and manufacturing planners frequently face a choice between nationally specified tool steels when selecting materials for hot-work tooling, dies, and heavy-duty components. The decision typically balances factors such as toughness versus wear resistance, hardenability versus weldability, service temperature capability versus cost and availability. H13 (AISI/ASTM) is a globally familiar hot‑work tool steel; “8407” is encountered as a Swedish industrial designation in some supply chains and technical documents.

The core selection dilemma is therefore often one of standard-system alignment and specification tolerance rather than a binary materials-performance gap: the Swedish-designated 8407 is used within national or regional supply systems and may be specified with slightly different composition limits and heat-treatment recommendations than US-standard H13. This article compares the two from the perspectives most relevant to engineering and procurement decisions.

1. Standards and Designations

• H13: Common designations — AISI H13, SAE J426, ASTM A681 (tool steel specifications), and equivalents under EN/W-Nr mappings (e.g., X40CrMoV5-1 family equivalents under EN). H13 is classified as a hot-work tool steel (chromium-molybdenum-vanadium alloy tool steel).
• 8407: Appears as a Swedish national or producer-specific designation used in some Nordic or European documentation. It is not a single global standard like AISI H13; instead, 8407 may be defined in a national (SS) standard, in manufacturer product literature, or in a customer specification sheet. It is generally considered within the category of hot-work/tool steels when used as an H13 analogue.

Classification: - H13: Tool (hot-work) steel — alloy tool steel designed for hot strength, toughness, and thermal fatigue resistance. - 8407: Tool (hot-work) steel designation in Swedish/national lists — likewise intended for hot-work applications but subject to national specification differences.

Note: When a procurement or engineering specification lists “8407,” verify whether it references a Swedish Standards Institute (SS) number, a supplier grade, or a cross-reference to a recognized EN/AISI grade.

2. Chemical Composition and Alloying Strategy

Below is a table presenting the key alloying elements commonly cited for AISI H13, and a note column for 8407 due to variability of national/supplier specifications. Always confirm 8407’s exact composition from the issuing standard or mill certificate.

Element	H13 (typical/spec range)	8407 (Swedish designation)
C (Carbon)	0.32 – 0.45 wt%	Supplier/standard dependent — often specified to achieve H13-like hardenability
Mn (Manganese)	0.20 – 0.50 wt%	Variable; check grade sheet
Si (Silicon)	0.80 – 1.20 wt%	Variable
P (Phosphorus)	≤ 0.030 wt%	Typical low-S/P limits per tool-steel practice
S (Sulfur)	≤ 0.030 wt%	Typical low-S/P limits per tool-steel practice
Cr (Chromium)	4.75 – 5.50 wt%	May be similar; verify exact chromium content
Ni (Nickel)	≤ 0.30 wt%	Usually minimal or absent
Mo (Molybdenum)	1.10 – 1.75 wt%	May be comparable to H13 to maintain hot strength
V (Vanadium)	0.80 – 1.20 wt%	May be comparable; can vary with carbide strategy
Nb (Niobium)	—	Rare in classic H13; some Swedish variants may include microalloying
Ti (Titanium)	—	Typically not a primary alloying element for H13
B (Boron)	—	Not standard in H13; trace in some alloys for hardenability control
N (Nitrogen)	—	Not a controlled alloying element for H13

Explanation of alloying strategy: - Carbon sets baseline hardness and strength and controls carbide formation. - Chromium provides hardenability, high-temperature strength, and oxidation resistance. - Molybdenum and vanadium form hard carbides that improve high-temperature strength, wear resistance, and temper resistance. - Silicon supports strength and oxidation resistance at elevated temperatures. - Small differences in Cr, Mo, and V between national specs can shift hardenability and secondary hardness characteristics; thus a Swedish 8407 with slightly different limits can show measurable differences in temper response or carbide distribution compared to H13.

3. Microstructure and Heat Treatment Response

Typical microstructures: - H13 (after proper quenching and tempering): tempered martensite with a dispersion of alloy carbides (Cr-carbides, Mo-carbides, V-carbides). In the annealed condition it is spheroidized/pearlitic-matrix depending on processing route used by the mill. - 8407: Expected microstructure is intended to match hot-work tool steels — i.e., martensitic matrix with alloy carbide dispersions after hardening. Exact carbide type and distribution depend on the precise Cr/Mo/V balance.

Heat-treatment response and processing routes: - Annealing (stress-relief/soft anneal): reduces hardness for machining and improves ductility. For H13, typical annealed hardness ~180–240 HB depending on processing; final hardness after full heat treatment is much higher. - Normalizing: refines grain size; multiple normalizing cycles can be used to homogenize large sections. - Quenching & tempering: H13 is commonly austenitized (typically 1000–1100 °C range depending on section size and supplier recommendation) and oil-quenched or gas-quenched to martensite, followed by multiple tempers to develop required tempering resistance. 8407, if aligned to H13, will use similar thermal cycles but with supplier-specific recommendations for austenitizing temperatures and tempering schedules. - Thermo-mechanical processing: forging and controlled rolling can refine prior austenite grain size and optimize carbides; Swedish process specifications sometimes emphasize precise forging and normalization cycles to achieve repeatable toughness.

Impact of composition on heat treatment: - Slightly higher Cr and Mo increase hardenability and secondary-hardening tendency; slightly higher V increases fine carbide dispersion and wear resistance. Thus small differences in 8407 vs H13 composition, if present, will manifest in temper response and secondary hardening behavior.

4. Mechanical Properties

Mechanical properties vary strongly with heat treatment and section size. The table below provides typical, representative ranges for AISI H13 and a qualitative column for 8407 where supplier specification is required.

Property	H13 (typical ranges after quench & temper)	8407 (representative/qualitative)
Tensile Strength (Rm)	~900 – 1800 MPa (heat-treatment dependent)	Comparable ranges expected if designed as H13-analogue; verify mill cert
Yield Strength (Rp0.2)	~700 – 1600 MPa	Comparable, depending on tempering
Elongation (A%)	~6 – 15%	Comparable; may be slightly higher or lower depending on carbide population
Impact Toughness (Charpy)	Varies with tempering: typically 10 – 50 J (depending on temper and section)	Depends on exact composition and heat treatment; Swedish specs may emphasize toughness for certain tool types
Hardness (HRC)	Annealed: ~18–24 HRC; quenched & tempered: ~44–54 HRC typical service range	Similar target hardness ranges; check supplier temper charts

Interpretation: - H13 is designed to balance high hot strength and reasonable toughness. It can be hardened to produce high tensile and yield strengths with moderate ductility. - If 8407 is specified to be an H13-equivalent, expect broadly similar mechanical performance, but differences in allowable composition tolerances or recommended heat-treatment cycles from Swedish specs can shift the exact strengths or toughness numbers. Always request heat-treatment instructions and certificates.

5. Weldability

Weldability of hot-work tool steels is influenced by carbon equivalent and hardenability. Common formulas used to evaluate preheat/postheat and filler selection:

• Carbon equivalent (IIW): $$ CE_{IIW} = C + \frac{Mn}{6} + \frac{Cr+Mo+V}{5} + \frac{Ni+Cu}{15} $$

• Pcm (European weldability parameter): $$ P_{cm} = C + \frac{Si}{30} + \frac{Mn+Cu}{20} + \frac{Cr+Mo+V}{10} + \frac{Ni}{40} + \frac{Nb}{50} + \frac{Ti}{30} + \frac{B}{1000} $$

Qualitative interpretation: - H13 typically has a moderate carbon content and significant Cr/Mo/V, giving a moderate-to-high carbon equivalent. This drives the need for controlled preheat, interpass temperatures, and post-weld heat treatment to avoid cracking and hardness in heat-affected zones. - 8407: if composition is similar to H13, expect similar weldability constraints. If a Swedish 8407 formulation reduces carbon or adjusts alloying, weldability may be marginally improved or degraded accordingly. - Best practices: use matching or slightly lower-hardness weld consumables, controlled preheat and interpass temperature, peening or post-weld tempering, and weld procedure qualification.

6. Corrosion and Surface Protection

• Neither H13 nor typical hot-work tool steels are stainless. Corrosion resistance is moderate due to chromium levels (4–5 wt% in H13), but they are not intended for corrosive environments without protection.
• Surface protection options: oil/grease, painting, plating (nickel/Chrome), and galvanizing (note galvanizing can be problematic for tooling due to diffusion and heat). For tooling exposed to humidity or cooling water, apply inhibitors or coatings (PVD/CVD, nitriding for wear and corrosion enhancement where appropriate).
• PREN is not applicable for non-stainless tool steels; the PREN formula: $$ \text{PREN} = \text{Cr} + 3.3 \times \text{Mo} + 16 \times \text{N} $$ is used for stainless corrosion prediction and is not used for H13/8407 class materials.

7. Fabrication, Machinability, and Formability

• Machinability: In the annealed condition both H13 and H13-equivalent Swedish grades are reasonably machinable but harder alloys and higher vanadium increase tool wear. Expect standard carbide tooling practices for roughing and high-speed finishing.
• Formability and bending: Hot-work tool steels are not highly formable in hardened condition. Forming is usually done in annealed condition; cold bending of finished H13 components is limited and requires careful stress relief to avoid cracking.
• Surface finishing: Grinding and EDM are common. EDM is often used for intricate cavities; microstructure and hardness influence EDM speed and electrode wear.
• Supplier notes: Swedish standards or supplier-specific 8407 grades may include recommended machining allowances, anneal recipes, and forging practices that differ from typical AISI H13 datasheets — follow supplier documentation.

8. Typical Applications

8407 (Swedish designation)	H13 (AISI/ASTM)
Hot-work die inserts in Nordic toolrooms where 8407 is a specified national grade; punches for forging with region-specific heat-treatment protocols	Hot-work dies, extrusion and die-casting tooling, forging dies, hot stamping dies, shear blades requiring thermal fatigue resistance
Cold-work applications when 8407 variant is tailored for specific carbide populations	Widely used globally in hot-work tooling where thermal cycling and abrasion occur
Supplier-specific niche tooling where national procurement prefers domestic specification and certification	Standard benchmark grade for international sourcing of hot-work tool steel

Selection rationale: - Use the grade that matches the performance requirement (wear vs toughness), the heat-treatment shop capability, and the procurement logistics. Where production is local to Sweden or Nordic suppliers, 8407 may provide specification and supply-chain advantages. For global sourcing and well-established data sheets, H13 is often preferred.

9. Cost and Availability

• H13: Widely available world-wide in bar, pre-hardened plates, billets, and forgings from many mills; competitive pricing due to large production volumes and extensive supply chains.
• 8407: Availability may be regionally concentrated (Sweden/Nordic suppliers) and could be offered either as a branded product or under national specification. Cost and lead time depend on whether 8407 is stocked by major distributors or requires special ordering from regional mills.

Procurement note: - When cost and lead time are critical, H13 often offers more supplier choice. When specification conformity or regional certification is required (e.g., contractual callouts to a national standard), 8407 may be necessary despite possible premium or lead-time impacts.

10. Summary and Recommendation

Summary table (qualitative):

Criterion	8407 (Swedish designation)	H13 (AISI)
Weldability	Similar constraints if composition matches H13; verify supplier Pcm/CE guidance	Moderate to challenging; requires preheat/postheat controls
Strength–Toughness balance	Supplier-dependent; can be tailored to emphasize toughness	Proven balance for hot-work: good temper resistance and toughness
Cost & Availability	Potential regional limitation; may be premium locally depending on demand	Broad global availability; generally more options and competitive pricing

Conclusions and recommendations: - Choose H13 if: - You need a widely specified, globally available hot-work tool steel with well-documented chemistry, heat-treatment charts, and a large supplier base. - Your application requires proven temper resistance, thermal fatigue resistance, and you require predictable global sourcing and support.

• Choose 8407 if:
• The procurement specification or regulatory/contractual requirement explicitly calls for a Swedish-designated grade or a supplier-certified 8407.
• You are working within Nordic supply chains where 8407 has established heat-treatment instructions, certifications, or advantageous lead times and where slight compositional or processing differences are desirable for a given tooling application.

Final practical advice: - Do not assume numeric equivalence; always request the mill certificate (chemical analysis and heat-treatment record) for 8407 and compare it to your H13 requirements. - Validate critical performance through sample parts or heat-treated test coupons, especially for welding procedures and for large cross-sections where hardenability and heat treatment response are most sensitive. - For welded assemblies, calculate $CE_{IIW}$ or $P_{cm}$ using the actual certified chemistry and define welding preheat/postheat and PWHT per the calculated risk of HAZ hardening and cracking.