Overview
DTI Washer
Direct Tension Indicator (DTI) washers with small raised protrusions on the bearing face that progressively flatten as bolt tension increases. When the protrusions are compressed to the specified gap, the required preload has been achieved — providing a reliable visual and feeler gauge check without relying solely on torque wrench accuracy. Manufactured to BS 7644 and used in HSFG bolt assemblies for bridges, industrial steel structures, and transmission towers where verified bolt tension is mandatory.
Key Features & Benefits
- Protrusions flatten at precise bolt preload — visual tension confirmation
- Eliminates over-tightening and under-tightening errors
- Feeler gauge check replaces sole reliance on torque wrench
- Hardened alloy steel for consistent indicator performance
- Mandatory for slip-critical structural connections
- Compatible with IS 3757 and BS 4395 HSFG bolt assemblies
- Black and HDG finishes for site and corrosive environments
- Reduces risk of joint failure due to inadequate preload
01
Small raised bumps on the washer surface flatten when the bolt reaches proper structural tension.
02
Feeler gauge testing verifies if correct clamping pressure is reached.
03
Avoids the need for expensive structural torque testing calibrations.
