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Our Design Catalogue

Self Drilling Screws - Dacromet


Dacromet range of Welfast Self Drilling Screws provides a pollution-free ceramic coating solution. The coating offers corrosion protection due to hot-dip galvanizing without discoloring the base/wood. These Screws with proper dacrotized coating typically withstand a 1000-hour salt-spray test, greatly minimizing the risk of hydrogen embrittlement thus eliminating the need of baking parts after the finish is applied.



Dacromet range of Welfast Self Drilling Screws offers the following additional features to that of a Bright Zinc Coated Self Drilling Screw:

  • Four-Way Corrosion Resistance:
    • Barrier Protection
    • Galvanic Action
    • Passivation
    • Self Repairing
  • Bi-Metallic Capabilities – One of the prime features of Dacromet Self Drilling Screws is Good Bi-Metallic corrosion resistance due to concentration of aluminum within the coating.
  • Solvent Resistant – Due to Dacromet coating, Welfast Self Drilling Screw become inorganic and thus resistant to solvents, gasoline, brake fluids, etc.
  • Embrittlement Free – The absence of acids in our screws due to Dacromet coating assures freedom from Hydrogen Embrittlement.
  • Paint Base – Dacromet range of Welfast Self Drilling Screws is a base for most paints, including electrodeposited paint.

How to Install :

  • Insert the 8 or 10 mm (according to required size) hex head adapter into the drill motor. Center the adapter into the drill’s chuck to ensure that adaptor does not wander.
  • Put on the safety glasses to protect your eyes.
  • Inspect the hex end of the adaptor for cleanliness. If metal shavings are built up inside the tip, insert the drilling end of the screw into the cavity of the hex head while holding the trigger of the drill.
  • Place a self-drilling screw into the hex head adapter.
  • Depress the trigger of the drill slowly, while the drilling tip of the screw rests against the metal. Increase the speed of the drill when the screw finds its center.
  • Stop drilling when the head of the self drilling screw tightens against the surface of the metal. If the drill you are using does not have a clutch, pay close attention to the screw head, as too much pressure will either snap the screw of strip the threads formed in the metal by the screw.
  • Perform Step 3 before you install another self drilling screw.

Hex Washer Head with Black Washer - Coarse Thread :

Sr. No. Size (mm) Drill Point Drilling Capacity (mm) Pcs / Box Pcs / Carton
1 5.5 x 14 x 25 #4 6 500 2000
2 5.5 x 14 x 35 400 1600
3 5.5 x 14 x 45 #5 8 350 1400
4 5.5 x 14 x 55 250 1000
5 5.5 x 14 x 68 200 800


Hex Washer Head with Black Washer - Fine Thread :
Sr.
No.
Size (mm) Drill Point Drilling Capacity (mm) Pcs / Box Pcs / Carton
1 5.5 x 24 x 25 #4 6 500 4000
2 5.5 x 24 x 38 400 1600
3 5.5 x 24 x 55 #5 8 250 1000
4 5.5 x 24 x 60 200 1600
5 5.5 x 24 x 65 200 800

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