As the internal flap is supplied with draft proofing strips, the slot size required will be offset, to allow any items posted through the letterplate set to flow into the inside of the house.
(It is advisable to use the stainless steel sleeves below, as your template for machining the slot through the door).
We supply two sizes of stainless steel U-channel as follows:
- Size 1 – 75mm deep x 228mm wide 50mm high, to suit a 70mm door leaf.
- Size 2 – 48mm deep x 228mm wide 50mm high, to suit a 44mm door leaf.
An insight into the manufacturing process…
Initially, castings are too hard and brittle to be worked into finished products, so they are subjected to an 80-hour heat treatment process known as annealing, after which they are cooled slowly, changing the carbon structure of the iron so that it is soft and malleable. Rough edges are removed, the castings are assembled and a rustproofing finish is applied.
A two-coat oven-cured paint process is then carried out, and then the products pass into our warehouse for final assembly, inspection and packaging ready for despatch.
For advice on product suitability and compatibility please call us on 01206 804317 or email us on firstname.lastname@example.org. We have stockists throughout the UK who will be able to offer specialist advice on all aspects of architectural ironmongery. Please contact us for details of your nearest stockist.