Zinc handles have been fitted for years to patio doors, with manufacturers thinking that zinc doesn’t corrode.
However an increasing number of door manufacturers and indeed homeowners are now coming to us asking why their zinc handles are corroding, as you can see in our case study video.
Why do zinc handles corrode?
The answer is in the base metal. Diecast zinc is very different to zinc galvanising and corrodes quickly because of its composition of multiple elements. As soon as the powder coated surface finish on the handle becomes scratched or damaged, the diecast zinc base metal soon pitts and corrodes.
Why do stainless steel handles not corrode?
Stainless steel’s corrosion resistance is a result of a very thin film oxide layer on the steel’s surface. This is formed by the alloying agents in the stainless steel, such as chromium and molybdenum, mixing with the oxygen in the water or air to form this thin but stable film of metal oxide. Stainless steel must have at least 10.5% chromium for the passive layer to form. The more chromium and molybdenum that is added, the more stable the passive layer becomes, and the better the corrosion resistance. Note that Molybdenum is only found in 316 Stainless Steel, not 304 Stainless Steel. The Molybdenum is what helps resist corrosion from chlorides such as saline (salt) air or acidic timber.
Our range of BLU 316 marine grade stainless steel hardware contains 16 to 18% Chromium and 2 to 3% Molybdenum. Therefore fitting hardware from our BLU range, with their lifetime guarantee, will keep your doors and windows looking good, and your customers happy, for years to come.
As part of our case study, we visited Beach House in Portreath, Cornwall, right on the edge of the sea. The patio doors on the property had been fitted for just over a year and the zinc patio handles were already badly corroded. Having used our BLU 316 stainless steel hardware range on another property, the homeowner contacted us to see what we could do to help sort. Whilst you couldn't get a tougher test for door hardware, being this close to the sea, we were confident our KM9 series Patio Door Handles made from 316 Stainless Steel would be up to it. The results as you can see in the images and video speak for themselves.
There are three main reasons why door manufacturers are switching to fit our KM9 Series Patio Handle to their patio straight sliding doors:
- They add value – customers have reported being able to increase their margin, for the same sliding door, after switching to fit our BLU KM9 series Patio Slide Handle.
- They won’t corrode – made from 316 stainless steel to prevent corrosion and supplied with a Lifetime Guarantee for that extra customer ‘peace of mind’
- Strength and Durability – the solid 316 stainless steel backplate provides added strength and durability, providing a quality feel and making them suitable even for larger leaf sliding doors.
So, should you choose handles made from zinc or stainless steel for your front doors, patio doors, windows?
The choice is yours. If you want a handle which is cheap but is going to fail, corrode and result in expensive site call-backs then fit a zinc handle. If however you want a handle which is going to enhance the look and operation of your patio sliding door, isn't going to corrode and is going to result in happy customers then we recommend you fit our BLU KM9 Series Stainless Steel Patio Slide Handle.
As the homeowner said after her new BLU Patio Door handles were fitted “Thank you for coming round and for fitting the new handles we are so happy with them”.
You can view our full range of BLU 316 Marine Grade Stainless Steel Hardware here.
To discuss in more detail how we can help with your hardware requirements please contact us on sales@coastal-group.com or 01726 871 025.
