You sold your customer a container of roofing screws. Steel looks good. Coating passes salt spray. But six months later: "Water is dripping through my metal roof."

The screw is still perfect. The bonding between washer and screw failed.

Not all bonded washers are the same.

Cold adhesive washers rely on surface glue. Peel strength is weak. Under sun, rain, and thermal cycling, the adhesive layer degrades and the washer slips off the screw. Water follows.

Hot vulcanized washers are a different story. Heat and pressure during vulcanization form permanent chemical cross-links between rubber and metal. The bond becomes part of the rubber itself.

Here's what that means for your roofs:

◎ Peel strength – Vulcanized bonding withstands installation torque without separation. Cold glue peels under stress.

◎ Temperature range – Remains elastic from -40°C to +120°C. Cold adhesive becomes brittle in winter and soft in summer heat.

◎ UV resistance – Vulcanized EPDM contains no sulfur compounds, so UV degradation is minimal. Cold adhesive joints crack and fail.

◎ Consistent sealing – Even with angled installation, hot vulcanized washers conform and seal.

Every roofing screw we supply comes with hot vulcanized EPDM washers. The rubber is chemically fused to the metal washer before assembly. No loose parts. No premature bond failure. Just a dry roof. Your customers don't see the bonding method. They only see the leak. Give them washers that stay put.

Want to test the difference?

Reply "Hot bond" and we'll send you samples—vulcanized vs. cold adhesive. Pull them off by hand. You'll feel the difference immediately.