---
title: "718H Steel for Injection Molding Inner Trays: Properties, Selection and Processing Guide - JATERSON"
description: "For 2026 high-volume plastic injection molding production, procurement and engineering teams are prioritizing mold materials that cut lead times and reduce long-term operational costs. 718H pre-hardened steel for inner tray molds delivers superior hardness, machinability and wear resistance compared to standard P20 grades, eliminating post-processing heat treatment delays while extending tool life by 30-40% for high-abrasion applications. Zhejiang-based injection molding manufacturer JATERSON sh..."
url: "https://www.jaterson.com/manufacturing/718h-steel-injection-molding-inner-trays-properties-selection-processing-guide.html"
language: "en"
type: "Article"
category: "Injection Molding Guide"
datePublished: "2026-08-29"
dateModified: "2026-08-29"
brand: "JATERSON"
manufacturer: "JATERSON"
image: "https://static.jaterson.com/uploads/industry/injection/8yzAgmrDNqeWB.webp"
---

# 718H Steel for Injection Molding Inner Trays: Properties, Selection and Processing Guide

For engineering and procurement teams sourcing inner tray molds for plastic injection molding,the performance of 718H as a core material depends on three high-priority variables that directly impact total cost of ownership,production lead time,and mold lifespan.The first and most critical variable is base material grade consistency,as even minor deviations in alloy composition or pre-hardening treatment can lead to uneven wear,premature cracking,or part quality defects.The second variable is processing parameter alignment during mold fabrication,as 718H’s pre-hardened structure requires specific cutting,polishing,and venting designs to retain its inherent benefits.The third variable is application-specific surface treatment selection,which must be matched to the plastic resin used for your inner tray to avoid unnecessary abrasion or corrosion over production runs.

## Core Variables That Determine 718H Inner Tray Mold Performance

![718H Steel for Injection Molding Inner Trays: Properties, Selection and Processing Guide](https://static.jaterson.com/uploads/industry/injection/8yzAgmrDNqeWB.webp)

### Material Grade Consistency

718H is a pre-hardened P20 modified steel,with added nickel to improve hardness and toughness without post-heat treatment.However,not all 718H grades are identical: low-cost uncertified variants often have nickel content as low as 0.3%,compared to the standard 0.8-1.2% required for consistent performance.For inner trays,which often have complex rib structures and tight dimensional tolerances,uneven hardness across the steel block can lead to uneven wear on rib edges,leading to part burrs or dimensional deviation after as few as 100k shots.At JATERSON,we only source 718H from certified steel mills with full material test reports (MTRs) provided to customers before production begins,to eliminate this risk.

### Processing Parameter Alignment

Because 718H is pre-hardened to 33-38 HRC,it requires slower feed rates and higher torque CNC cutting tools compared to softer P20 steel.Common processing mistakes include using standard high-speed steel cutting tools instead of carbide-coated tools,which leads to micro-cracks on the mold surface that are invisible to the naked eye but expand during repeated heating and cooling cycles in [injection molding](https://www.jaterson.com/knowledge/injection-molding-all/).For inner tray molds,which often have large flat surfaces and multiple venting channels,improper cutting can also lead to uneven vent depth,causing part burn marks or insufficient filling during production.We recommend a feed rate of **150-200 mm/min** for rough cutting 718H,and **50-80 mm/min** for finish cutting,with a spindle speed of 8000-12000 RPM for carbide tools,to avoid surface damage.

### Application-Specific Surface Treatment

718H has moderate corrosion and wear resistance,but it is not suitable for all inner tray applications without additional treatment.For example,if your inner tray is molded from PVC or PET,which release corrosive byproducts during heating,untreated 718H will develop surface corrosion within 6 months of continuous production,leading to pitting on the part surface.For inner trays molded from glass-filled resins (20%+ glass content),untreated 718H will show visible wear on contact surfaces after 150k shots,requiring re-polishing that adds 3-5 days of downtime.Matching the correct surface treatment to your application can extend 718H mold life by 30-40% with only a 10-15% increase in mold cost.

## Key 718H Material Properties vs Common Inner Tray Mold Alternatives

![Common Inner Tray Mold Failures: Why 718H Material Is the Reliable Fix](https://static.jaterson.com/uploads/industry/default/G44ezi0ZAs85G.webp)

To help teams make informed selection decisions,we have compiled a comparison of 718H to other common mold materials used for inner tray applications,based on our 20+ years of manufacturing experience in Zhejiang.All metrics are aligned to 2026 standard industry testing protocols for mold steel.

| Material Grade | Pre-hardened Hardness (HRC) | Machinability Score (1-10,10=easiest) | Wear Resistance Score (1-10,10=best) | [Corrosion Resistance](https://www.jaterson.com/knowledge/resistance-to-corrosion/) Score (1-10,10=best) | Relative Cost (vs P20 = 1x) | Best Use Case for Inner Trays |
| --- | --- | --- | --- | --- | --- | --- |
| P20 | 28-32 | 9 | 5 | 4 | 1x | Low-volume runs (100k parts),non-abrasive resins (PP,PE) |
| 718H | 33-38 | 7 | 7 | 5 | 1.4x | Mid-to-high volume runs (100k-1M parts),general resins (ABS,PC,PP with fillers) |
| S136 | 48-52 (post heat treat) | 4 | 9 | 9 | 2.8x | High-volume runs (>1M parts),corrosive resins (PVC,PET),food-grade applications |
| H13 | 46-50 (post heat treat) | 3 | 8 | 6 | 2.2x | High-temperature resin runs (PA,PEEK),high-wear applications |

For most mid-to-high volume inner tray production runs (100k to 1M parts) using general engineering resins like ABS,PC,or unfilled PP,718H offers the best balance of cost,lead time,and performance.Unlike S136 or H13,it requires no post-fabrication heat treatment,cutting 3-5 days off mold production lead time,and is 60% less expensive than S136 while delivering 40% better wear resistance than standard P20.

## 718H Inner Tray Material Selection Checklist

To avoid common selection mistakes and ensure your 718H inner tray mold meets production requirements,use the following actionable checklist during the sourcing process:

- Confirm 718H material certification from the steel mill,including explicit alloy composition (1.2311/1.2312 equivalent for European standard grades,or AISI P20+Ni for US standard grades) and pre-hardened hardness testing reports from 3 points across the steel block to avoid uneven heat treatment.
- Cross-reference material hardness with your planned production volume: select 36-38 HRC 718H for runs over 500k parts,and 33-35 HRC for runs between 100k-500k parts to balance machinability and wear resistance.
- Validate compatibility with the plastic resin used for your inner tray: if your tray uses 20%+ glass filled PP or PC,add a 0.02mm hard chrome plating to the 718H mold surface to reduce abrasion by 40%.
- Factor in lead time requirements: 718H requires no post-fabrication heat treatment,cutting 3-5 days off mold [production lead time](https://www.jaterson.com/knowledge/production-lead-time/) compared to grades like S136 or H13 that require heat treatment after cutting.
- Confirm your manufacturer has experience processing 718H steel for inner tray molds,as improper feed rates during CNC cutting can cause micro-cracks that lead to premature mold failure after 200k-300k shots.

## Common Processing and Implementation Mistakes to Avoid

Based on our experience producing hundreds of 718H inner tray molds for global customers,we see two recurring mistakes that lead to unexpected costs and downtime:

First,many teams skip pre-production hardness testing across the full steel block.Even certified 718H can have hardness deviations of up to 3 HRC if the mill’s heat treatment process is inconsistent,leading to uneven wear across the mold surface.For inner trays with tight dimensional tolerances (±0.05mm or less),this deviation can lead to out-of-spec parts after 200k shots,requiring full mold replacement months earlier than planned.Always request hardness test data from at least 5 points across the steel block before fabrication begins.

Second,many buyers assume 718H is suitable for all resin types without additional treatment.As noted earlier,corrosive resins like PVC or high-fill resins require surface plating to prevent premature wear.We recently worked with a European consumer electronics customer who initially skipped chrome plating for a 718H inner tray mold used for 30% glass-filled PC,leading to visible scoring on the tray surface after 120k shots.Adding a 0.02mm hard chrome plating to the reworked mold extended its service life to 800k shots,with no additional quality defects.

## Cost and Lead Time Impact of 718H for Inner Tray Molds

When evaluating 718H against other materials,it is critical to calculate total cost of ownership (TCO) rather than just upfront mold cost.For a typical 2-cavity inner tray mold for consumer electronics packaging:

- Upfront cost for P20 mold: ~$2,500,expected lifespan 100k shots,per-part [mold cost](https://www.jaterson.com/knowledge/tooling-cost/): $0.025

- Upfront cost for 718H mold: ~$3,500,expected lifespan 600k shots,per-part mold cost: $0.0058

For production runs over 200k parts,718H delivers a 75% reduction in per-part mold cost,offsetting the 40% higher upfront cost within the first 3 months of production.

In terms of lead time,718H molds typically take 10-14 days to fabricate for standard inner tray designs,compared to 14-18 days for S136 molds that require post-fabrication heat treatment.For teams facing tight product launch deadlines,this 4-5 day lead time reduction can have a significant impact on time-to-market.

## Quality Control Checks for 718H Inner Tray Material

At JATERSON,we implement three non-negotiable quality control checks for all 718H inner tray molds before shipping to customers:

1.Material certification verification: We provide full mill MTRs for all 718H steel,including alloy composition and pre-hardening hardness data,for customer approval before fabrication begins.

2.Post-fabrication hardness test: We test hardness at 10 points across the mold cavity and core to ensure deviation is less than **±1 HRC**,eliminating uneven wear risk.

3.Surface quality check: We conduct surface roughness testing for all inner tray contact surfaces,ensuring Ra 0.8μm to prevent part sticking and reduce demolding force requirements.

We also provide a 6-month warranty for all 718H inner tray molds against material or processing defects,for production runs up to the rated lifespan for the selected grade.

For most mid-to-high volume inner tray injection molding projects,718H is the most cost-effective and reliable material choice,as long as teams prioritize grade consistency,proper processing,and application-aligned surface treatment.If you have questions about whether 718H is suitable for your specific inner tray application,our engineering team can provide customized guidance based on your production volume,resin type,and dimensional tolerance requirements.

## Related Resources

- [Injection Molding Guide](https://www.jaterson.com/manufacturing/injection-molding/)
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