materials-finishes

Diamond-Like Carbon (DLC) Coatings: Sub-Micron Hardness for Master Key Pins

Engineering Overview: Engineering breakdown of Diamond-Like Carbon (DLC) thin-film coatings on stainless steel lock pins, providing 3000 HV hardness and 0.05 friction.

Technical & Engineering Specifications

Hardness 3000 - 3500 HV Diamond-Equivalent Hardness
Application Commercial Master Key Split Wafers & High-Cycle Pins
Film Thickness 1.0 to 2.0 um
Coating Technology Plasma-Assisted Chemical Vapor Deposition (PACVD DLC)
Friction Coefficient 0.05 Ultra-Low Friction

Sub-Micron Carbon Nanotechnology

In high-frequency commercial master key cylinders operating over 1,000,000 cycles, pin wear alters bitting depths. Diamond-Like Carbon (DLC) coating deposits a diamond-bonded carbon layer (1–2 μm).

Nanomechanical Properties

  • Vickers Hardness: 3000 to 3500 HV (sp3 diamond carbon matrix).
  • Friction Coefficient: $\mu = 0.05$ (Ultra-Low Dry Friction).
  • Zero Wear: Prevents master split wafer erosion over decades of use.

Frequently Asked Engineering & Selection Questions

Q1: Why are master key pins coated with Diamond-Like Carbon (DLC)?

DLC provides 3000+ HV diamond hardness and self-lubricating 0.05 friction, preventing pin wear from altering master key combinations.