H13 tool steel

Identity and product definition

BÖHLER's W302 lists 52–56 HRC after oil or salt-bath quenching and 50–54 HRC after air or vacuum quenching, for its 1020–1080°C hardening range. The ranges describe the named product and quench routes. Qualify the tool section and verify the finished hardness after tempering. BÖHLER W302 hardening data

H13 is a chromium-molybdenum-vanadium hot-work tool steel designation. Böhler's W302 brochure associates its product with AISI H13, UNS T20813, EN X40CrMoV5-1 and material number 1.2344. Its average analysis is carbon 0.39%, chromium 5.20%, molybdenum 1.40% and vanadium 0.95% by mass. Those are producer average values, not a complete generic H13 acceptance specification. Böhler, W302 technical brochure

Uddeholm markets Orvar Supreme as an H13-type product and lists typical chemistry of C 0.39%, Si 1.00%, Mn 0.40%, Cr 5.20%, Mo 1.40% and V 0.90%. Its claim of compliance with NADCA #207 Superior H13 requirements belongs to that named product; it is not a quality claim for every steel sold as H13. Uddeholm, Orvar Supreme product page

What hot-work performance means

Böhler describes W302 through hot strength, wear resistance, toughness and heat-checking resistance. These are different performance dimensions, not one interchangeable “high-temperature rating.” Böhler, W302 applications and properties

For selection, describe the work material, contact pressure, tool temperatures, heating/cooling cycle, lubrication and cooling conditions. Separate gradual surface heat checking from gross cracking, plastic deformation and wear. A harder tool may not solve a failure caused by insufficient toughness, cooling layout or stress concentration.

EDRO's H13 ESR offering lists die casting, hot extrusion and forming tools, with flat plate and round-bar processing options. These are supplier capabilities and application leads, not a promise of a particular die life. EDRO, H13 ESR

Supplied condition and final heat treatment

Uddeholm's Orvar Supreme brochure describes ESR production and a soft-annealed delivery condition of approximately 180 HB. The delivered machinable stock is therefore distinct from a hardened-and-tempered finished die. Uddeholm, Orvar Supreme technical brochure, edition 13, June 2021

Record the complete thermal route: rough machining, stress relief where required, preheating, austenitizing, quench, tempering and subsequent surface treatment. Section size, geometry and furnace capability belong in the process qualification. A furnace setpoint alone does not demonstrate the required core temperature or cooling response.

The Böhler W302 brochure illustrates the importance of quench conditions: for its stated 1020–1080°C hardening range, it lists obtainable hardness of 52–56 HRC in oil/salt bath versus 50–54 HRC in air/vacuum. These are product-guidance ranges, not guaranteed hardness throughout arbitrary tool sections or a complete heat-treatment instruction. Böhler, W302 hardening guidance

For process planning, agree the final hardness range and required toughness with the toolmaker and heat treater. Do not accept as-quenched hardness as evidence that tempering, dimensional stability or service readiness has been achieved.

Tempering evidence and tool-size limits

Uddeholm's brochure recommends at least two tempers with cooling to room temperature between them and warns against 425–550°C tempering because of reduced toughness. Its tempering curves were obtained on 15 × 15 × 40 mm samples cooled in forced air; it explicitly warns that real tools may attain lower hardness because of tool size and treatment parameters. Uddeholm, tempering section and curve qualification

For a geometry-only illustration, a 100 mm-thick tool is 100 / 15 = 6.67 times the 15 mm sample dimension. This ratio does not calculate a hold time or cooling rate. It simply shows why direct transfer of a small-sample curve needs a heat-transfer and process assessment.

Surface treatments and finish

Uddeholm describes nitriding as creating a wear-resistant hard layer, but warns that the brittle layer can crack or spall under thermal or mechanical shock, with risk increasing as layer thickness increases. Core treatment and surface treatment must be selected together. Uddeholm, nitriding and nitrocarburizing

Specify case-depth definition, surface-hardness test/load, final finish and any compound-layer restrictions separately from bulk HRC. A nitrided surface value is not the core hardness and does not establish resistance to gross fracture. Review grinding, EDM, polishing and coating operations for their effect on the final surface and dimensional acceptance.

Do not treat H13 as a stainless corrosion grade. Define storage, cleaning and protective practices for the actual tool environment independently of its hot-work designation. Supplier statements about wear resistance do not qualify resistance to a cleaning chemical or molten material under every operating condition.

Repair welding and service records

Uddeholm's separate Orvar Supreme welding guide distinguishes annealed and hardened starting conditions, controls temperature during welding, and gives different post-treatment routes. It warns that excessive local temperature can cause distortion, soft zones or cracking. Filler selection also matters when the repaired surface must be polished or photo-etched. Uddeholm, Orvar Supreme welding recommendations

Use the full producer procedure with a qualified repair plan. Identify the previous tempering history, damage extent, joint preparation, filler, thermal controls and required inspection. Do not turn one quoted preheat value into a universal H13 welding recipe. Document the repair and its acceptance before returning the tool to production.

Ordering and source editions

An actionable order includes grade/product, melt or remelt route where required, section and orientation, supplied condition, certificate and required cleanliness/toughness criteria. Attach the finished-tool hardness, inspection and surface-treatment requirements to the manufacturing route. Retain failures by mechanism and operating history rather than promising a universal number of shots or cycles.

Uddeholm's technical brochure is printed edition 13, 06.2021, despite its 2024 upload path. The Böhler brochure bears W302 DE -11.06 - 1000 SPS; that printed code is retained without assigning an independently verified revision date. No printed revision date was verified for the separate welding guide or web product pages. Confirm required current producer instructions and contractual editions.

See also grades, tempers and conditions.