Tool Steel Locator Block: Wire EDM Machining with Precision Step & Chamfer, True 90° Locating Surface

Tagged: Wire EDM Locator Precision Locator Block Tool Steel Machining

We manufactured a batch of precision tool steel locator blocks for an automated assembly line integrator. These blocks feature multi-step profiles, angled chamfers, and true 90° locating surfaces. Using slow wire EDM instead of conventional milling, we eliminated tool deflection and achieved consistent sub-micron accuracy across all critical locating features.

Project Overview

Project Name	Precision Tool Steel Locator Block
Key Metric	Specification
Material	Tool steel (hardened 55–60 HRC)
Locating Surface Angle	90° ±0.01°
Step Position Tolerance	±0.003mm
Surface Roughness (locating faces)	≤0.4μm Ra
Chamfer Angle Tolerance	±0.1°

Key Technical Highlights

True 90° Locating Surface: Wire EDM produced a perfect right-angle corner without radius or tool marks, ensuring repeatable part positioning in assembly fixtures.
Precision Step & Chamfer: Multi-pass wire EDM achieved ±0.003mm step height accuracy and ±0.1° chamfer angle, eliminating secondary operations.
Hardened Material Capability: Directly cut tool steel at 55–60 HRC with no pre-machining softening, preserving material integrity and wear resistance.
Surface Integrity: Achieved Ra≤0.4μm on all locating faces, reducing friction and improving long-term positioning repeatability.

Quality Verification

Every locator block was inspected using Hexagon CMM (1.5μm repeatability) for step positions, chamfer angles, and perpendicularity. Locating surface squareness was verified with precision granite square and optical comparator. All critical dimensions held within ±0.005mm over full batch.