Precision Tolerance Standards

Comprehensive breakdown of our dimensional accuracy, geometric tolerancing, and industry-compliant inspection protocols for CNC, sheet metal, and molding processes.

Defining Accuracy at Scale

At MetalCore, tolerance isn't just a specification—it's a commitment. We maintain rigorous standards across all manufacturing processes, ensuring parts meet or exceed ASME Y14.5-2018 and ISO 2768 requirements.

Whether you're producing flight-critical aerospace components, high-volume automotive parts, or biocompatible medical devices, our engineering team optimizes designs for manufacturability while preserving your exact tolerance requirements.

"We don't just meet tolerances. We engineer processes to consistently hold them across production runs of 10 or 10,000 parts."

Process Accuracy Comparison

CNC Machining
±0.005" / ±0.127mm
Sheet Metal
±0.010" / ±0.254mm
Injection Molding
±0.003" / ±0.076mm

*Standard tolerances. Tighter specs available upon engineering consultation.

Industry Standards We Follow

📐

ASME Y14.5-2018

Dimensioning and Tolerancing standard governing GD&T application, datum reference frames, and feature control frames.

Primary Standard
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ISO 2768-1 & -2

General tolerances for linear/angular dimensions and geometric tolerances for free-fitting (mK/MK) to fine-fitting (mH/MH) classes.

Global Compliance
📏

IT Grade System (01-18)

ISO tolerance grades mapped to our machining capabilities. We routinely achieve IT2-IT5 for precision turning and milling.

Precision Mapping
✈️

AS9100 Rev D

Aerospace quality management standard requiring documented tolerance verification, material traceability, and PPAP/FAI reporting.

Aerospace Certified

Standard Tolerance Ranges by Process

Default tolerances applied when drawings lack explicit callouts. Custom requirements are priced based on tooling, cycle time, and inspection complexity.

CNC Machining (Mill & Turn)

Feature TypeStandard TolerancePrecision TierNotes
Linear Dimensions±0.005" (±0.127mm)IT4 / FineCan hold ±0.001" with CMM verification
Holes (Drilled/Tapped)+0.005"/-0.000"H7/H8Reamed/bored for tighter fits
Concentricity/Runout±0.003" TIRGD&T ControlledRequires soft jaws or live tooling
Surface FinishRa 32 - 63 μinStandardRa 8-16 available (polishing/Honing)

Sheet Metal Fabrication

OperationStandard ToleranceMATERIAL ThicknessNotes
Laser/Waterjet Cut±0.008" (±0.20mm)0.020" - 0.375"Tighter on flat stock, wider on thick plate
Bend Angles±1° to ±2°Springback compensatedTight tolerances require CNC press brakes with angle measurement
Flange Length±0.015" (±0.38mm)0.030"+Dependent on tooling radius and K-factor
Flatness±0.030" / ftPost-bendStress relief or post-forming available

All tolerances conform to ISO 2768-mK unless otherwise specified. Custom GD&T frameworks supported.

GD&T Application & Control

We use modern GD&T to define part functionality, reduce ambiguity, and maximize yield. Our engineers review all drawings for proper datum selection and tolerance stack-up analysis.

Position

Controls hole/pattern location relative to datums

Flatness

Ensures surfaces lie within a parallel boundary zone

Profile of Surface

Controls form, orientation, and location simultaneously

Runout

Controls circular/cylindrical features during rotation

Parallelism

Ensures axes or planes remain equidistant

Perpendicularity

Controls 90° relationships between features

Inspection & Verification Methods

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CMM Metrology

Bridge & scanning CMMs for 3D coordinate measurement.

  • Probed & laser scanning probes
  • Temperature compensated chamber
  • ISO 10360 certified
📊

First Article Inspection

Complete dimension validation before production release.

  • AS13100 compliant reports
  • Full drawing cross-off documentation
  • Digital signatures & traceability
📈

Statistical Process Control

Real-time monitoring to prevent drift and scrap.

  • X-bar & R control charts
  • Cpk/Ppk capability analysis
  • Automated SPC dashboards

Tolerance & Engineering FAQ

What happens if I don't specify tolerances on my drawing?

Default tolerances per ISO 2768-mK (medium tolerance for linear dimensions) or ASME Y14.5 general tolerances will be applied. For critical features, we recommend explicit callouts to avoid ambiguity and reduce inspection costs.

How much does tighter tolerance cost?

Tighter tolerances increase machining time, require slower feeds, specialized tooling, and additional inspection cycles. Typically, moving from ±0.005" to ±0.001" can increase part cost by 20-40%. Our engineers can optimize your design to reduce tolerance cost without sacrificing function.

Do you provide certified inspection reports?

Yes. Every batch includes a dimensional report. First Article Inspections (FAI), Material Certifications (Mill/Certs), and PPAP packages are available for aerospace, medical, and automotive programs.

Can you hold tight tolerances on large parts?

Yes, but thermal expansion and machine deflection become factors. We use granite tables, thermal stabilization, and in-process probing to maintain accuracy on parts up to 60" x 40" x 30".

Need Custom Tolerance Specifications?

Our manufacturing engineers will review your drawings, run tolerance stack-up analyses, and provide an optimized quote within 24 hours.

Request Engineering Review →
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