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Compare Security Fasteners

When choosing the right security fastener, not all options offer the same level of protection, reliability, or installation control. In this comparison, we break down two standout products side-by-side to help you evaluate their strengths, limitations, and ideal use cases. Whether you’re securing high-value infrastructure or simply looking to deter casual tampering, understanding how these fasteners differ can make all the difference.

Security Fastener
Our Thoughts
Good For
Not Good For
Driver Availability
Maximum Torque (MFG Claim)
Minimum Quantity
Average Break-In Time
Cost Per Fastener
Samples Available
Keyway Type
Tool Control
Head Style Options
Material Options
Reusability
Tamper Resistance
Tool Compatibility
Installation Method
Visual Deterrence Level
Removal Risk if Tool Leaks
Lead Time to Purchase
Where to Buy

Kinmar Permanent by Hafren Security Fasteners

Kinmar Permanent by  Hafren Security Fasteners

The Kinmar Permanent screw is a true one-way fastener designed for permanent installations where no future access is needed. Its unique shape makes unauthorized removal extremely difficult without specialized tooling or destruction. However, its broad, flat top offers limited resistance to physical attacks like grinding or gripping tools. The overall security relies more on deterrence than invulnerability.

Kinmar Permanent
  • Permanent Fixtures
  • Low-Maintenance Installations
  • Visual Deterrence
Kinmar Permanent
  • Applications Requiring Maintenance
  • High-Tool Exposure Environments
  • Resistance to Physical Destruction
Kinmar Permanent
None: One-way design, no driver for removal. Kinmar Permanent
Not specified; high torque before shearing. Kinmar Permanent
Not specified; likely moderate (e.g., 100 pieces). Kinmar Permanent
Extremely high: Permanent, resists all removal attempts. Kinmar Permanent
$1.62 - $5.35 Kinmar Permanent
Not specified; likely available for bulk orders. Kinmar Permanent
One-way keyway, shears after installation. Kinmar Permanent
None: Permanent design, no removal tools. Kinmar Permanent
Button. Kinmar Permanent
Steel, stainless steel; A2, A4 options. Kinmar Permanent
Non-reusable; permanent installation. Kinmar Permanent
Extremely high: One-way design prevents removal. Kinmar Permanent
No tools for removal; one-way design. Kinmar Permanent
Manual or power-driven; shears after installation. Kinmar Permanent
High: One-way design signals permanence. Kinmar Permanent
None: No removal tools exist. Kinmar Permanent
Not specified; likely 1–4 weeks. Kinmar Permanent

Not Available in stores.
Order online.

Purchase from Accu

Kinmar Permanent

Tri-Groove 

Tri-Groove

This fastener is widely available and lacks meaningful tool control or tamper resistance. While often marketed as a "security screw," it does not meet our standards for the security classification. It may deter casual tampering but offers very little protection against intentional removal.

Tri-Groove
  • General Fastener Use
Tri-Groove
  • Security Use
Tri-Groove
Widely available; sold in stores and online. Tri-Groove
Moderate; varies by size and material. Tri-Groove
Low: Often available in small packs. Tri-Groove
Low: Easily removed in minutes. Tri-Groove
Low: Varies by supplier, size, and material. Tri-Groove
Likely available from distributors. Tri-Groove
Standard, not proprietary. Tri-Groove
N/A: Bits widely available to public. Tri-Groove
Button, flat, pan, socket; varies by supplier. Tri-Groove
Steel, stainless steel (e.g., 304, 316), sometimes brass or zinc-plated—depends on supplier. Tri-Groove
Reusable with matching bit; integrity depends on torque and material. Tri-Groove
Low: Easily defeated with standard bits or modified tools. Tri-Groove
Compatible with standard bits; widely available tools. Tri-Groove
Manual or power-driven with bit; standard installation process. Tri-Groove
Low: Recognizable shape signals basic security, not highly deterrent. Tri-Groove
N/A: Tool/Bit is widely available. Tri-Groove
N/A: Commonly stocked item. Tri-Groove

Available in stores.
Order online.

Purchase from Grainger

Tri-Groove

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