The Difference Between Malleable and Cast Iron Door Hardware.
There is often confusion about the difference between malleable
iron and cast iron hardware. There are many cheaper cast iron
products for sale now, many of which are identical in size,
shape and general appearance to quality door and window
hardware. The difference is that cast iron will break.
Kirkpatrick Ltd for Walsall in the UK, has been synonymous with
the production of high quality malleable iron builders's
ironmongery for over 140 years. Producing an extensive range of
Black Antique and Plain Gothic styles.
Kirkpatrick's malleable iron products are hand-made in the their
foundry in Walsall using green sand casting process. At this
stage the castings are hard and brittle and cannot be hammered,
so they are subjected to a heat treatment known as 'annealing'.
In this process the castings are surrounded by an inert
haematite ore within iron drums and loaded into ovens of six to
eight tons capacity. The ovens take about two days to reach the
annealing temperatue of 980 C. The castings are then soaked at
this temperature for around 80 hours, after which they are
allowed to cool naturally. During this process the carbon
structure of the iron is changed. The resulting castings are no
longer hard and brittle, but soft and malleable.
After shot blasting and grinding to remove any rough edges the
castings are then assembled into finished or semi-finished
products. Following assembly a rust proofing finish may be
applied and a two-coat paint process is carried out, before
being passed for final inspection.
Kirpatrick malleable iron products you can be confident that you
are getting a product which is both functional and highly
decorative and one that, well maintained, will give many years
of service and pleasure. Have a look at the wide range available
at http://www.arciron.com