The method that inspects the lining steel of model steel door window normally has:  

1.Cite weight method estimate, that is, weigh weigh pvc folding door price philippines, with reinforced steel doors and Windows weight, otherwise light.  

2.With magnets on the doors and Windows of the frame, fan, such as magnet adsorption profiles there are reinforced steel, on the contrary, no.  

3. Observe whether there are screws fastening the section steel on the frames and fans of doors and Windows, and verify whether there are reinforced sections.  

Anyhow, the customer should be careful when product of choose and buy, choose the product of normal manufacturer as far as possible, strict examination, lest be deceived.