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

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

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.

Industry Applications

This locator block is ideal for:
✓ Automated assembly line tooling
✓ CNC workholding fixtures
✓ Inspection gauge bases
✓ Modular pallet systems

Why Partner With Us?

• Proven wire EDM precision for hardened tool steel
• True 90° internal/external corners without radius
• In-house stress-relief & cryogenic treatment for dimensional stability
• 25+ years of fixture & locator manufacturing experience