Our Blog

DIN 1.2316: The Complete In-Depth Material Guide

DIN 1.2316 is a pre-hardened stainless plastic mold steel under German DIN standard. It uses a three-alloy system with high chromium, molybdenum and small amounts of nickel. This material balances corrosion resistance, mirror polishing performance and toughness for complex mold cavities well. This article fully explains the technical strengths of DIN 1.2316, a widely used precision mold steel, from chemical composition, core properties to application cases.

Table of Content

Hot product

DIN 1.2316
DIN 1.2316
1.2316 steel turned bar
1.2316 steel turned bar
1.2316 steel milled surface
1.2316 steel milled surface
1.2316 milling service
1.2316 milling service
1.2316 material milled surface
1.2316 material milled surface

1. Material Definition of DIN 1.2316

DIN 1.2316 mold steel is a classic pre-hardened martensitic stainless plastic mold steel following German DIN rules. Its international grade is X38CrMo16, and the matching Chinese standard grade is 3Cr17NiMo. It is classified as improved 420 stainless mold steel in the industry. It is a mainstream precision mold steel for plastic molds that needs good corrosion resistance, high polishing performance and no extra hardening treatment.
 

DIN 1.2316 steel is made with two common melting methods: VD vacuum refining and ESR electroslag remelting. It is fully quenched and tempered before delivery, so you can machine molds directly without extra heat treatment. It widely replaces traditional P20, 718, 420 and 2083 mold steels. It also offers better cost performance than S136 mirror stainless steel. DIN 1.2316 is the standard material for plastic molds with corrosive melt, high surface appearance needs, medical and cosmetic product molds.

 

Full supporting processing services are available, including CNC milling & grinding, nitriding surface treatment, mirror polishing, ultrasonic flaw detection, CNC precision machining and EDM texturing. It fits the whole supply chain: mold steel traders, mold workshops and plastic injection factories.

 

2. Standard Chemical Composition of DIN 1.2316

DIN 1.2316 is medium-carbon stainless mold steel with high chromium, molybdenum and nickel. Nickel works as a key auxiliary alloy element. Its standard chemical contents decide four core features: rust resistance, polishing ability, toughness and dimensional stability (mass fraction %):
 
  • Carbon (C): 0.33–0.43%. It balances basic hardness, wear resistance and cutting performance.
  • Chromium (Cr): 15.50–17.50%. It forms a tight chromium passivation film, the main element for anti-rust and anti-corrosion performance.
  • Molybdenum (Mo): 0.80–1.30%. It improves hardenability, low-temperature impact toughness, pitting resistance and temper stability under high temperature.
  • Nickel (Ni): normally controlled at 0.5–1.0%, average 0.8%. It is a critical balancing element.
  • Manganese (Mn): 0.30–1.00%, Silicon (Si): 0.30–1.00%. They refine internal metal structure and improve flow during casting.
  • Phosphorus P ≤0.035, Sulfur S ≤0.035. Low harmful impurities greatly lower risks of internal inclusion, porosity and cracks.
 

Key Functions of Nickel in DIN 1.2316

Greatly improve base toughness and reduce brittleness caused by high chromium

High-chromium martensitic steel is naturally brittle. Around 0.8% nickel refines martensite grain and lowers brittleness. At the same hardness, impact toughness rises clearly. Molds with deep ribs, thin walls and sharp corners rarely chip off. This is one main reason DIN 1.2316 works much better than regular 420 steel for complex molds.

 

Work with chromium and molybdenum to boost corrosion and pitting resistance

Nickel stabilizes the surface passivation film with stronger adhesion. When exposed to acid from PVC plastic or salt spray, the film does not break easily to form corrosion pits. Its long-term anti-rust ability beats nickel-free 420 steel.

 

Make metal structure even for consistent polishing and texturing

Nickel stops carbides from gathering unevenly. The inner structure becomes uniform, so no cloudy marks or pinholes show after polishing. Etched textures have even depth without uneven spots. ESR grade with stable nickel can reach high-standard mirror finish.

 

Cut internal heat stress and raise dimensional stability

During pre-hardening tempering, nickel eases phase change stress. Thick plates and big forgings have tiny hardness difference between surface and core. Less deformation happens after CNC machining and repeated hot-cold injection cycles. Precision multi-cavity molds keep tight size tolerance.

 

Keep good toughness under low working temperature

In cold winter workshops or molds cooled quickly by water, nickel prevents sharp toughness drop. Tiny cracks do not form under repeated force from ejector pins and mold opening/closing.

The three-alloy mix of high chromium + molybdenum + nickel makes DIN 1.2316 a special anti-corrosion stainless steel for plastic molds. It is different from regular carbon mold steel and standard pre-hardened steel. ESR remelted material has higher purity and stricter nickel-chromium-molybdenum control than regular VD vacuum steel, perfect for precision molds with strict surface requirements.
 

3. Hardness, Physical & Mechanical Basic Properties of DIN 1.2316

DIN 1.2316 is pre-hardened before delivery with standard hardness 28–32 HRC, equal to 280–325 HB. This common hardness range removes the need for full quenching or second tempering.
 

Exact Mechanical Data (20°C room temperature)

  • Tensile strength σb: 1020–1120 MPa
  • Yield strength σ0.2: 855–980 MPa
  • Elongation after fracture δ5: 10%–14%
  • Room temperature impact toughness KV: 18–25 J. Nickel reduces toughness gap between surface and core of thick forgings.
  • Elastic modulus: 205000 MPa
 

Physical & Thermal Data

  • Density: 7.85 g/cm³
  • Linear expansion coefficient (20–100°C): 10.4×10⁻⁶ K⁻¹. It matches thermal expansion of PC, PMMA and PVC plastics to reduce size shift during injection cycles.
  • Room temperature thermal conductivity: 24–26 W/(m·K). Stable heat dissipation controls mold deformation from temperature difference.
  • Dimensional change rate under long-time 300°C injection <0.03%, with strong thermal fatigue resistance.
 
This steel has excellent hardenability. For forgings up to 300 mm thick, hardness difference between core and surface ≤2 HRC. The nickel-molybdenum alloy brings high strength, low deformation and stable size. It resists thermal fatigue and repeated injection stress. It machines well with smooth EDM surface. After nitriding, surface hardness hits HV 680–720+ to greatly lift wear life. It fits multi-cavity precision molds, large plastic molds and mass-production molds with long service time.
 

4. Eight Detailed Performance Advantages of DIN 1.2316

Pre-hardened, no quenching needed to shorten production and remove deformation & crack risks

DIN 1.2316 is fully stress-released during factory tempering. Nickel cuts leftover heat stress. You can directly complete full machining: CNC roughing, finish milling, deep hole drilling, tapping, EDM, texturing and mirror polishing.

Regular quenched stainless steel must go through high-temperature quenching & tempering after rough machining. It easily bends, deforms, cracks at deep ribs and goes out of tolerance, costing lots of rework hours. DIN 1.2316 skips full heat treatment, cutting mold production time over 30%. It fits precision plastic molds, complex multi-cavity molds and rush export mold orders. The advantage stands out for small cosmetic and medical multi-cavity molds. Steel can be cut and ground immediately without waiting for heat treatment.
 

Strong acid & alkali resistance, long anti-rust and anti-pitting performance for corrosive plastic raw materials

DIN 1.2316 uses a three-element anti-corrosion system: 16% chromium plus 0.8% nickel and 1% molybdenum. A tight continuous chromium oxide film forms automatically after machining. Nickel strengthens film adhesion to resist hydrochloric acid from PVC, fluoride from flame-retardant plastic, acid additives in POM and corrosive gas/liquid from modified ABS under high heat.

Its anti-corrosion ability is over 3 times better than regular pre-hardened P20 and 718 steel. In humid southern factories, water-cooled molds, coastal salt-spray workshops and 24-hour mass production, mold cavities rarely form rust, water marks or corrosion pits. Rust will not leave scratches or black spots on plastic parts to lower rework frequency for polishing. Even if molds sit unused for weeks, simple wiping removes all rust marks to cut maintenance cost. It is the specified anti-corrosion steel for PVC pipe molds, flame-retardant switch housing molds and acid-modified plastic molds.
 

Graded polishing capacity; ESR grade reaches high transparent mirror finish

Two quality grades are available: VD vacuum refined and ESR electroslag remelted. Nickel evens metal structure and stops uneven carbide gathering, creating clear polishing gaps between grades:

  • VD vacuum grade: tiny inner impurities, max polishing finish 6000–8000 grit. Meets demands for regular transparent housings and standard cosmetic bottles.
  • ESR electroslag grade: ultra-fine metal structure, very low sulfur & phosphorus, no inner holes or porosity. Nickel stably controlled at 0.7–0.9%. Polishing reaches steady 10000–12000 grit high gloss with no cloud, pinholes or orange peel marks on plastic parts.
Minimum surface roughness after polishing hits Ra 0.02 μm. It perfectly fits transparent PC lamp covers, PMMA optical lenses, acrylic decorative parts and high-end transparent cosmetic shells with high light transmission demands. Polishing factories save material loss, working hours and raise good product rate.
 

Very stable etching & texturing, even texture depth without uneven marks or cracks

Even carbide distribution and nickel-refined grain keep uniform etching speed. Light grain texture, deep lychee grain, fine wire drawing and 3D carved texture can be processed evenly with consistent depth, no uneven color or edge cracks.

Many stainless steels crack at deep ribs during etching. DIN 1.2316 gains strong base toughness from nickel and molybdenum. Molds with complex height differences and thin wall corners never crack after texturing. It works for high-end home appliance plastic shells, auto interior plastic parts and large-capacity wash packaging molds that need uniform texture. Texturing factories face much less rework than with regular 420 steel.
 

Balanced high toughness at high and low temperatures, anti-chipping for thin walls & deep ribs

0.8% nickel mixed with molybdenum balances hardness and impact toughness. Under 28–32 HRC pre-hardened state, room temperature impact value stays steady. Toughness only drops slightly under cold injection conditions. Stress concentrated areas (deep reinforcing ribs, 0.8–2 mm thin walls, sharp steps, long thin inserts) do not chip from mold locking or repeated ejector hits. It resists chipping better than pre-hardened S136H at the same hardness and lowers cost for mold fitting and welding repair. Service life rises clearly for irregular medical device shells and multi-rib electronic connector molds.

 

Supports surface nitriding for better wear and anti-sticking, fits glass fiber filled modified plastic

Two main hardening methods are supported: gas soft nitriding and ion nitriding. Nitride layer thickness controllable from 0.08–0.2 mm, surface hardness hits HV 680–720 after nitriding. Friction drops greatly to stop plastic melt sticking and scratching molds.

Nickel does not block nitrogen penetration. The steel keeps full stainless performance after nitriding without weaker corrosion resistance. The nitride layer sticks tight and hardly peels off. For long mass production with 10%–30% glass fiber or mineral powder filled plastic, non-nitrided molds last 300,000–400,000 shots, while nitrided molds reach 500,000–700,000 shots to extend service life greatly. All nitriding factories can process this steel easily with no risk of chromium loss or surface rust after nitriding.
 

Easy cutting, low tool loss and lower total machining cost

The medium pre-hardened hardness of 28–32 HRC plus nickel-refined grain lowers cutting resistance. Compared with quenched S136 and 420 stainless steel at HRC 48–52, cutting resistance drops around 40% during milling, drilling and tapping. Carbide cutting tools wear slower, machine feed speed can increase to lift CNC efficiency over 25%. EDM material removal speed stays steady with no brittle white layer on surface, so later polishing and texturing are not affected. Fitters spend less time hand grinding molds. Large mold factories cut total cost on cutting tools, electricity and labor for batch mold making.

 

High purity & safe material, passes third-party tests to meet medical & food environmental standards

High-purity ESR grade keeps stable nickel, chromium and molybdenum ratios with no excessive harmful heavy metals. It smoothly passes SGS heavy metal test, food contact safety test and basic medical biocompatibility test with no lead, arsenic or cadmium over limits.

It meets domestic and international standards for food plastic containers, disposable medical supplies and medical beauty device shells. Full material certificates and test reports support export customs clearance. DIN 1.2316 fits plastic injection factories and mold makers for cross-border export orders.
 

5. Application Range & Full Supply Chain Scenarios of DIN 1.2316

DIN 1.2316 is a widely used high-grade pre-hardened stainless plastic mold steel covering the full chain of mold steel trade, mold machining and plastic injection forming:
 
  • Corrosive plastic molds: PVC pipe molds, flame-retardant plastic switch housings, injection molds for plastic with acid additives
  • Cosmetic packaging molds: transparent perfume bottles, cream jars, cosmetic shells and bottle cap molds
  • Medical plastic molds: syringe housings, medicine box shells, sterile medical supplies and small medical device shell molds
  • Transparent optical plastic molds: PC car lamp covers, PMMA optical lenses, transparent home appliance shells and light-transmitting decorative part molds
  • Food contact plastic molds: food storage boxes, plastic tableware and drinking container molds
  • Precision electronic molds: small home appliance plastic shells, electronic connectors and small digital accessory molds
  • Special matched parts: blow mold cavities, extruder mold inserts and mold cores/sleeves for long-term mass production
 

6. Full In-Depth Comparison: DIN 1.2316 vs S136 Steel

Chemical Composition Difference

  • DIN 1.2316: Cr 15.5–17.5%, C 0.33–0.43%, Mo 0.8–1.3%, Ni 0.5–1.0% (average 0.8%). Higher chromium plus nickel & molybdenum for better toughness and pitting resistance, three-element anti-corrosion alloy system.
  • S136: Cr 13.5–14.5%, C 0.35–0.45%, no molybdenum, no controlled nickel content. Lower chromium, missing nickel and molybdenum for toughness & pitting resistance, naturally more brittle base metal.
 

Delivery State & Basic Hardness

  • DIN 1.2316: Standard pre-hardened at 28–32 HRC, machine directly without quenching & tempering. Nickel balances heat stress during tempering in factory.
  • S136: Delivered soft annealed at HB 220. Must go through rough machining, then quenching at 1020–1050°C plus two low-temperature tempering to reach HRC 48–52 final hardness. Extra high-temperature heat treatment brings deformation and crack risks. No nickel to ease phase change stress, so thick large parts deform more easily.
 

Anti-Corrosion & Anti-Rust Performance

DIN 1.2316 has clear advantages: higher chromium + molybdenum + nickel work together to stop pitting. It performs better against PVC, acid plastic and salt spray. Nickel stabilizes passivation film, so pits and rust appear over 30% later during long production with corrosive plastic. It is the first choice for coastal, high-humidity workshops and 24-hour production with corrosive melt.

 

S136 offers basic anti-rust performance only for neutral non-corrosive plastic. Long mass production with strong corrosive material easily creates local pitting rust without nickel & molybdenum to fix broken passivation film.

 

Max Mirror Polishing & Material Purity

S136 takes the lead for top mirror finish: most commercial S136 uses unified ESR electroslag melting with consistent high purity. Steady 12000–15000 grit ultra-mirror finish with zero cloud or pinholes. It is the top pick for optical lenses and ultra-transparent medical parts.

 

DIN 1.2316 has two grades (VD / ESR). Nickel evens metal structure; ESR grade hits 10000 grit mirror finish for most transparent parts and high-end packaging. It is slightly weaker than S136 for ultra-high light transmission top optical components.

 

Toughness, Anti-Chipping & Suitability for Complex Cavities

DIN 1.2316 delivers better overall toughness: around 0.8% nickel plus molybdenum greatly lift impact resistance. Pre-hardened soft base metal avoids cracks or welding repair on deep ribs, thin walls, sharp corners and long thin inserts. Large thick plates have even nickel content with tiny inside-outside toughness gap for stable large molds.

S136 with quenched high hardness is brittle without nickel to balance toughness. Thin walls, sharp corners and deep ribs easily form tiny cracks under force. Complex irregular molds face higher scrap risk. Welding repair is harder and cracks more easily after welding.

 

Cutting Difficulty & Machining Cost

DIN 1.2316 lowers total machining cost: pre-hardened at 28–32 HRC, nickel-refined grain reduces cutting resistance for easier machining, less tool loss and no waiting for heat treatment. Total working hours cut over 30% for small & medium molds.

S136 annealed soft material machines easily in rough cutting, but quenching & tempering takes 7–15 extra days. Finish machining works on hard HRC 48–52 steel with fast tool wear and slow feed speed. Total cost on labor and cutting tools rises 20%–35%.

 

Wear Improvement after Nitriding

Both steels can be nitrided to boost wear resistance. DIN 1.2316 nickel base metal eases stress in nitride layers to avoid peeling, with no drop in anti-corrosion ability after nitriding. S136 brittle high-hardness base holds nitride layers well but chips easily under impact force. Both fit high-wear glass fiber plastic mass production with similar shot counts after nitriding.
 

Market Price & Cost Performance

Compare same ESR electroslag grade: DIN 1.2316 sells 25%–35% cheaper than S136. VD vacuum refined DIN 1.2316 has an even bigger cost advantage.
Material selection logic by cost performance:
  • Choose DIN 1.2316: molds for corrosive PVC & flame-retardant plastic, medical & cosmetic packaging, complex cavities, rush delivery mass molds and budget-controlled export mold orders.
  • Choose S136: ultra-transparent optical lenses, non-corrosive high-end transparent luxury packaging, precision small molds requiring flawless ultra-mirror finish.
 

Precise Application Difference

DIN 1.2316 fits: PVC corrosive plastic, flame-retardant plastic, medical & cosmetic packaging, rush mass molds, large complex cavity molds, export mold orders with cost limits.

S136 fits: ultra-transparent optical lenses, non-corrosive high-end transparent luxury packaging, precision small molds requiring perfect mirror surface with zero defects.

 

7. Common Delivery Sizes of 1.2316 Steel & Full Supporting Processing Services

Main available DIN 1.2316 profiles on market: precision ground plates, six-side milled flat plates, solid round bars, square steel, large-size forged thick plate blanks and custom special forgings.
 
Full downstream supporting processing: steel cutting, six-side precision milling & grinding, flat surface fine grinding, mirror polishing, gas & ion nitriding, ultrasonic internal flaw inspection, re-tempering heat treatment, outsourced CNC rough machining and EDM texturing. We can provide original factory material certificates, spectrum test reports and mechanical performance test sheets. It supports two purchase modes: full container bulk export for mold factories & steel traders, and small-batch cutting retail.
 

Translation Notes (follow your request)

  • Keep all technical data, grades, standards, percentages completely unchanged as original text;
  • Use simple industrial English, short sentences, avoid complex professional clauses, fit overseas B2B mold steel website SEO reading;
  • Repeat DIN 1.2316 properly to retain original keyword density, no deletion of core technical logic and comparison details;
  • All mold industry common terms adopt international standard simple expressions for overseas buyers & engineers.

Conclusion

📩 Contact Keyspark Steel now if you need →

📧 Email: Sales@keysparksteel.com
📱 Mobile/WhatsApp: +86 150 2405 6480

Related Posts