UV Durability Test Report

 

Why Torque-Tight | Independent Testing

UV Durability Test Results:
Torque-Tight vs. Competing Indicators

Third-party laboratory testing shows Torque-Tight indicators hold their color and structure through 500 hours of accelerated UV exposure. The leading imported competitor began failing at hour 288.

Passed — Full 500 Hours

Torque-Tight Standard Indicators

4.5–5.0

AATCC color rating maintained throughout the full 500-hour test. No significant fading. No structural degradation. Made in USA.

Failed — Hour 288

Wheel Check (imported competitor)

2.5

AATCC color rating dropped to 2.5 by hour 288 — significant fading well before the test concluded. Imported product.

About the Test

Torque-Tight commissioned independent UV weathering testing at Element Materials Technology, an ISO 17025 accredited laboratory. The test was conducted under ASTM G154-23 Cycle 1 — the industry-standard accelerated UV weathering protocol for plastics and coatings exposed to outdoor conditions.

Test Report EWA176974. Both Torque-Tight indicators and Wheel Check competitor indicators were evaluated under identical conditions for 500 continuous hours.

Test Parameters

Laboratory

Element Materials Technology

Accreditation

ISO 17025 certified

Test standard

ASTM G154-23 Cycle 1

Report number

EWA176974

Test duration

500 hours continuous

Measurement

AATCC color rating (1–5 scale)

Products tested

Torque-Tight standard indicators vs. Wheel Check competitor indicators

Test cycle

UV-A 340nm lamp, 8 hr UV / 4 hr condensation

Results by Interval

Color was measured at regular intervals using the AATCC gray scale, which rates color change from 5 (no change) to 1 (severe change). A rating of 4 or higher is generally considered acceptable for safety-critical, high-visibility applications.

Hours Elapsed Torque-Tight (AATCC Rating) Wheel Check (AATCC Rating) Status
0 (baseline)

5.0

5.0
Both start equal
100 hours

4.5

4.0
TT holds strong
200 hours

4.5

3.5
Gap widens
288 hours

4.5

2.5
Wheel Check fails
500 hours

4.5–5.0

2.5
TT passes full test

Understanding the AATCC Rating Scale

AATCC Gray Scale — Color Change Rating

5

5.0 — No change. Color identical to baseline. Full visual performance maintained.

4

4.0 — Slight change. Minor color shift, still fully acceptable for safety-critical high-visibility applications.

3

3.0 — Noticeable change. Meaningful fading visible to the naked eye. Approaching the limit of acceptable performance.

2

2.5 — Significant change. Where Wheel Check measured at hour 288. Substantial fading. High-visibility function compromised.

1

1.0 — Severe change. Near complete color loss. Indicator no longer performs its visual function.

A 2.5 AATCC rating means the indicator has faded severely enough that its high-visibility function is compromised — the whole reason the product exists. Torque-Tight held 4.5 to 5.0 for the full 500 hours.

Why UV Performance Matters for Fleet Operations

☀️

Outdoor exposure is constant

Commercial vehicles operate outdoors year-round. A lug nut indicator mounted on a truck in Phoenix or a transit bus in Denver faces direct UV exposure every day. Indicators that fade lose their visual function — the whole point of the product.

👁️

Faded indicators fail inspection

A faded, discolored indicator is harder to read during a pre-trip walkaround. Drivers miss rotation. Inspectors miss misalignment. The safety benefit disappears long before the indicator physically falls off.

💰

Replacement cost adds up

Fleets that use imported indicators frequently report replacing them every 12–18 months due to fading and curling. Torque-Tight's UV stability means longer service life and lower total cost of ownership.

🏛️

Transit agencies need documented performance

Procurement decisions for transit agencies and government fleets require documented, third-party evidence of product performance. This test report — ISO 17025 accredited, ASTM G154-23 standard — provides that documentation.

Material That Makes the Difference

Torque-Tight standard indicators are molded from virgin polymer low-density polyethylene (LDPE), a UV-stabilized formulation specifically selected for outdoor durability. This material has a Vicat softening (not melting) point of 214°F (101°C) per ASTM D1525 — well above operating temperatures at the wheel end — and is manufactured to consistent tolerances in the USA

The UV stabilization is built into the polymer, not applied as a surface coating. Surface coatings degrade; stabilized polymer does not.

Imported indicators are typically manufactured from lower-grade polyethylene without UV stabilization packages. The test results show exactly what that difference looks like after real-world exposure time.

Buy America Compliance

Torque-Tight standard lug nut indicators are manufactured in the United States and are Buy America compliant, suitable for transit agency procurement under FTA Buy America requirements. This test report, combined with the Made in USA manufacturing status, makes Torque-Tight the specification-compliant choice for government and transit fleet procurement.

Wheel Check & Checkpoint are imported products and do not qualify under Buy America requirements.

Test Documentation

Report: EWA176974 — Element Materials Technology

Accreditation: ISO/IEC 17025 — scope covers accelerated weathering testing of materials

Standard: ASTM G154-23, Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials, Cycle 1 (UVA-340, 8 hr UV at 60°C / 4 hr condensation at 50°C)

Measurement: AATCC Evaluation Procedure 1, Gray Scale for Color Change

Full test report available to procurement departments and fleet managers upon request. Contact sales@torque-tight.com or call (734) 245-9681.

Available in 10, 100, 1,000, and 4,000-pack configurations.
All sizes ship from the USA.

Available in 10, 100, 1,000, and 4,000-pack configurations.
All sizes ship from the USA.