Roofing Screws
Hex Flange head / self drilling Rusted Finished
Available sizes 5.5 * 25 / 5.5 * 55
Description
Roofing Screws (short 5.5×25, long 5.5×55)
Expected qualities
- ● The sharpness of cutting-edge
- ● Tightening washer
- ● Durability
Properties of our screws
Sharpness – Trial drilling done on 6mm thick mild steel plate – can use more than 5 times while competitor’s screws can use only 3 times – Quality OK.
Tightening washer – 2.5mm thick EPDM washer; EPDM – Ethylene Propylene Diene Monomer; Synthetic Rubber.
Durability – Salt spray test for 500hrs corrosion condition environment / No contact corrosion possible.
What is the C4 corrosion condition?
C4 Environments externally typically are industrial areas and/or coastal areas with moderate salinity. Internally, typical environments include chemical plants, swimming pools and coastal shipyards.
What is a RUSTED finish?
- ● 1st coating – 5 microns Zn protective layer
- ● 2nd coating – Epoxy adhesive layer
- ● 3rd coating – 15 microns ceramic coating
No contact corrosion – No direct contact with the sheet due to ceramic coating. Hence no contact corrosion.
