What Is Zintek Coating? A Guide to Zinc Flake Surface Treatment for Bolts & Fasteners

Introduction

If you've been sourcing high-strength bolts or fasteners for automotive, construction, or industrial applications, you may have come across the term Zintek coating. In recent months, we've received a growing number of inquiries from European and North American customers asking about this surface treatment — what it is, how it works, and whether it's the right choice for their application.

This article breaks it all down.

What Is Zintek Coating?

Zintek is a zinc flake coating system applied to fasteners and metal components to provide superior corrosion resistance. It belongs to the same family as well-known systems such as Geomet® and Dacromet®, but with a key differentiator: Zintek coatings contain integrated lubricants, allowing the coefficient of friction to be precisely adjusted during application.

This makes Zintek especially valuable in automotive assembly, where consistent torque-tension relationships are critical for safety and quality control.

Key Technical Advantages

  • Adjustable friction coefficient — The built-in lubricant allows engineers to dial in the exact K-factor required by OEM specifications, reducing the risk of under- or over-torquing during installation.
  • No hydrogen embrittlement — Unlike electroplated zinc coatings, Zintek is applied at low temperatures without an electrochemical process. This eliminates the risk of hydrogen embrittlement, making it especially suitable for high-strength steels (Grade 10.9, 12.9, and above).
  • Excellent chemical resistance — Zintek-coated fasteners demonstrate strong resistance to acids, alkalis, and other aggressive chemicals encountered in automotive underbody and industrial environments.
  • RoHS & ELV compliant — Zintek coatings are free of hexavalent chromium (Cr6+), making them fully compliant with the EU's End-of-Life Vehicle (ELV) Directive and RoHS regulations — a critical requirement for European OEM supply chains.

OEM Approvals & Specifications

Zintek has earned approval from several major global OEMs, confirming its reliability in demanding production environments:

OEM Specification Approved Coating System
Bosch 0-204-Y82-119 Zinteck
Daimler DBL 9440.40 Zinteck, Zinteck Top, Zinteck Top L
PSA (Stellantis) B15 3320 Zinteck 200, Zinteck Top LF
Volkswagen TL245 otl-t601 Zinteck 200

Zintek vs. Standard Zinc Plating: What's the Difference?

Many buyers are familiar with standard electroplated zinc (blue-white or yellow passivated), which is widely used for general-purpose corrosion protection. Here's how Zintek compares:

Property Electroplated Zinc Zintek (Zinc Flake)
Corrosion resistance (salt spray) 72–200 hrs 500–1,000+ hrs
Hydrogen embrittlement risk Yes (electrochemical process) No (thermal cure)
Suitable for Grade 10.9 / 12.9 Requires baking; risk remains Yes, fully safe
Friction coefficient control Limited Precise, adjustable
Cr6+ free (RoHS/ELV) Depends on passivation Yes
OEM automotive approvals Limited Bosch, Daimler, VW, PSA, etc.

Typical Applications

Zintek-coated fasteners are widely used in:

  • Automotive chassis, suspension, and engine components
  • Heavy machinery and off-highway equipment
  • Wind energy and solar mounting structures
  • Infrastructure and construction hardware exposed to harsh environments
  • Any application requiring high-strength fasteners with reliable torque control

Is Zintek Right for Your Application?

If your project involves high-strength bolts (Grade 10.9 or 12.9), requires OEM-compliant surface treatment, or operates in a corrosive or chemically aggressive environment, Zintek is worth serious consideration.

At FULLERKREG Fasteners, we supply DIN/ISO standard bolts with Zintek surface treatment to customers across Europe and North America. Whether you need standard hex bolts, socket head cap screws, or custom configurations, we can provide technical data sheets, salt spray test reports, and competitive wholesale pricing.

📩 Contact us for a quote or to request a sample batch for evaluation.

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