Andrews Fasteners company in manufacturing Direct Tension Indicators Washers (DTI Washers) in well know in construction industry company based in United States – TurnaSure. All our washers are marked with our headmark FAST (previously AND.).
Benefits of using Direct Tensions Indicators Washers:
- The use of DTIs is the simplest way of ensuring that bolting assemblies are tensioned properly;
 - The use of DTIs saves cost on inspection;
 - No torque figures are required, only feeler gauges;
 - Risk reduction on over tightening;
 - DTIs are manufactured in compliance with EN 14399-9 and can be supplied with CE approved preloadbolting assemblies;
 - Unique curved protrusion design of Turnasure DTIs reduce necessary of using nut face / bolt face washers for 8.8 grade assemblies;
 - Direct Tension Indicators (DTI) retain their accuracy regardless of their surface condition during tightening, be they oiled, coated or even rusted.
 - DTIs provide assurance of slip resistance.
 
Product Range
| Description | Specification | Size range | 
|---|---|---|
| Direct Tension Indicators Washers (DTI Washers) | EN 14399-9 Alternative to BS 7644-1, ASTM F959M  | M12–M36 | 
Finishes available
| Finish | Specification | 
|---|---|
| S/C Self Colour  | Bare | 
| SHER / SHERA Sherardized Vapour galvanising  | EN ISO 17668 EN 13811 BS 7371-8 BS 4921  | 
| MZP / MG Mechanical Applied Coating (Galvanized/Zinc)  | BS 7371-7 ASTM B695  | 
For technical information and advice on the use of Direct Tension Indicators Washers supplied by Andrews Fasteners please see our Technical Support Page.

