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1.2316 Prehard Steel: Ready-to-Use Time-Saving Mold Material

Mold factories worry more about complicated procedures than high material cost. If you buy annealed steel, you have to send it out for heat treatment after machining. Quenching distortion will cause dimensional tolerance out of range and ruin all previous work. 1.2316 Prehard Steel refers to 1.2316 delivered in pre-hardened condition, made to solve this pain point. The steel mill completes quenching and tempering in advance, and the steel you receive reaches 28-34 HRC, machinable and ready for direct use. This article explains the advantages, applicable limits and risk avoidance tips of prehardened 1.2316 from the practical production perspective of mold manufacturers.

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1.2316 material milled surface

What Is 1.2316 Prehard Steel & The Logic of Prehardened Delivery

 
In the mold steel industry, “pre-hardened” means a delivery state. Steel mills finish quenching and high-temperature tempering before shipment to adjust hardness to the range fit for direct machining and service. The standard hardness of 1.2316 prehard steel is 28-34 HRC with precise design. The lower limit 28 HRC ensures sufficient wear resistance and deformation resistance to prevent premature mold abrasion caused by insufficient hardness. The upper limit 34 HRC stays within the ideal range for high-speed CNC machining and EDM, bringing acceptable tool life without cutting efficiency loss. Another core merit of prehardened steel is zero heat treatment risk. The steel delivered has finished quenching and tempering, only requiring subsequent machining and finishing. It completely avoids common defects from self-operated heat treatment such as quenching distortion, cracking and uneven hardness. For 75% of injection molding applications, DIN 1.2316 prehard steel with 28-34 HRC fully meets production demands.
 

1.2316 Prehard Steel vs Annealed Steel: When to Choose Prehardened Grade

 

1.2316 steel has two delivery options: prehardened at 28-34 HRC and annealed at 20-25 HRC.

 

Scenarios to select prehardened steel: The required service hardness of molds falls between 28-34 HRC, covering most injection molds; factories without internal heat treatment equipment or unwilling to bear heat treatment risks, as prehardened steel can be machined directly without extra procedures; small and medium mold shops with tight delivery schedules, since prehardened stock can be processed immediately without waiting for outsourced heat treatment queues.

 

Scenarios to select annealed steel: Customers demand customized higher hardness such as 40-48 HRC for high-wear molds, and annealed steel serves as the standard blank for post-machining heat treatment; molds with extremely complex shapes, multiple deep cavities or thin walls, the softer 20-25 HRC annealed grade reduces tool loss; manufacturers with mature in-house heat treatment processes, annealed steel offers maximum processing flexibility.

 

Simple judgment rule: If your target service hardness stays 28-34 HRC, 1.2316 prehard mold steel is the optimal solution for faster, stable and worry-free production.

Comparison ItemPrehardened (28-34 HRC)Annealed (20-25 HRC)
Direct machining after deliveryYesYes
Require post-processing heat treatmentNoYes (quenching + tempering)
Risk of heat treatment distortionZero (processed by steel mill)Exists (3-5% rejection rate)
Tool consumption levelModerateLow
Lead timeShortLong (includes outsourced heat treatment cycle)
Hardness adjustabilityFixed at 28-34 HRCCustomizable target hardness

Practical Machining Guide for 1.2316 Prehard Steel

 

For CNC machining of 28-34 HRC prehardened steel, proper cutting tools and parameters are critical. TiAlN or AlCrN coated carbide cutters are recommended. These two coatings perform well on hard materials with excellent heat resistance and low friction coefficient.

 

Suggested cutting parameters: Roughing speed 80-100 m/min, feed per tooth 0.08-0.15 mm/tooth, cutting depth 1-3 mm; Finishing speed 100-150 m/min, feed per tooth 0.05-0.10 mm/tooth, cutting depth 0.1-0.5 mm.

 

Adequate coolant supply is necessary. Martensitic stainless steel has poor thermal conductivity, and local overheating will trigger work hardening and accelerate tool wear. Stress relief treatment at 200°C for 2 hours must be conducted after EDM to eliminate residual stress inside the recast white layer.

 

One forbidden operation for 1.2316 prehard steel: Local repair welding without post-weld heat treatment during machining. Hardness fluctuation inside the welding heat-affected zone will lead to uneven mold abrasion during operation.

 

Delivery Specifications & Acceptance Standards of 1.2316 Prehard Steel

 

Delivery specifications and acceptance criteria directly affect subsequent processing when purchasing 1.2316 prehard steel.

 

Common available stock sizes: 10-80 mm thick hot-rolled plates (prehardened with black surface); 80-400 mm thick forged & upset-drawn plates (prehardened with machined black surface).

 

Standard delivery condition for plastic mold steel is prehardened black surface, the default state of DIN 1.2316 prehard steel.

 

Three mandatory inspection items for acceptance

 
  1. Hardness test: Measure at least three positions on each plate (two ends plus center). All readings shall range 28-34 HRC with hardness difference no more than 3 HRC.
  2. Five core chemical elements on MTC: C, Si, Mn, P, S must comply with standard limits, especially P ≤0.030% and S ≤0.020%.
  3. Ultrasonic test: UT inspection report is compulsory for plates thicker than 80 mm to exclude internal cracks and residual shrinkage cavities.
     

    If all three items pass inspection, the 1.2316 prehard material can be put into machining safely.

FAQ:

Q1: What to do if received 1.2316 Prehard Steel hardness is below 28 HRC?

A: Contact your supplier immediately for re-inspection or return. 28-34 HRC is the guaranteed quality standard of 1.2316 prehard steel. Hardness lower than 28 HRC indicates incomplete quenching and tempering from the steel mill. Do not put it into production reluctantly. Low-hardness molds will suffer abnormal rapid abrasion and cause heavy losses.

A: Yes. 1.2316 prehard mold steel at 28-34 HRC fits WEDM processing. Note that a 0.01-0.03 mm thick tensile-stressed recast layer forms on wire-cut surfaces. Conduct stress relief tempering at 200°C for 2 hours or polish the white recast layer gently with fine sandpaper after wire cutting to avoid microcracks during mold service.

A: Technically feasible. Perform full annealing first to lower hardness to 20-25 HRC for machining, then carry out quenching and tempering to reach target hardness. But this practice wastes all advantages of prehardened steel. If you need hardness higher than 28-34 HRC, purchase annealed 1.2316 from the start at a lower cost. The core value of prehardened steel lies in direct machining without secondary heat treatment.

Conclusion

Choosing the correct delivery state of mold steel lifts machining efficiency by 30% and shortens lead time by one week. If you hesitate between prehardened and annealed 1.2316 grades or have doubts on acceptance standards, engineers from Keyspark Steel are ready to offer professional judgment. We own 20 years of industry experience with in-stock goods shipped on the same day to support your reliable purchasing decision.

 

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

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