Finishes
Aluminum
FSB 0105
Aluminum natural colored anodized
Immersion and Absorption
Deep Staining of the Oxidized Coating
Aluminum is the most common metal in the Earth’s crust. It occurs widely in feldspar, mica, and clay materials and is mainly extracted from bauxite.
Aluminum is a light metal (relative density 2.699 g/cu.m) with a melting point of 660 degrees Celsius. Its natural color is silvery white. It can be cast or rolled into virtually any shape, including foil.
Aluminum is extracted from bauxite in two separate stages. Pure Aluminum oxide (alumina) is generated, and this is then broken down into Aluminum and oxygen by a process of electrolysis in a fused cryolite solution. Despite the high energy cost of the initial extraction process, Aluminum is environmentally sound. Being a lightweight among metals, it saves energy when used. It can also be fully recycled at a fraction of the cost involved in its manufacture.
After machining, the surface is anodized. This is an electrochemical process which trans-forms the surface of the metal into a given thickness of Aluminum oxide. FSB uses the standard GS process (direct-current sulphuric acid electrolysis) to form its anodized coatings. This process produces an oxidized layer approximately 10 µm thick. Coating hardness is between 250 and 350 kp/ sq.mm (Vickers), equivalent to 2,500 - 3,500 N/sq.mm.
The silvery oxidized layer can be stained to extend the range of possible finishes. FSB makes use of two methods:
- Surface and penetrating staining by immersion and absorption
- The silvery white anodized aluminum is chemically stained in organic and inorganic dye solutions.
- Deep staining of the oxidized coating
- Metal compounds are electrolytically implanted into the silvery oxidized layer using an alternating current. This is also known as the two-step method.
Once coloration is complete, the surface is sealed. This ensures abrasion strength as well as color and weather fastness.
Aluminum essentially needs no looking after. The surface is protected by natural or artificial anodisation. Marks can be removed with water and a soft cloth.
Harder materials can gouge or abrade an Aluminum surface. The scratches left by rings are a typical example. Though such blemishes may be a visual nuisance, they in no way impair the functional properties of the product. There are many users who view the impact of time on the objects of everyday use as an ennobling process.
FSB processes only pure melting alloys, similar to ASTM B179–75, as follows:
| AlMg3 | AlMg1 | AlMgSi0,5 |
|---|---|---|
| Material No. 3.3541.02 (based on DIN 1725) | Material No. 3.3315 (based on DIN 1725) | Material No. 3.3206 (based on DIN 1725) |
Stainless Steel
FSB 6204
Stainless steel satin finish
FSB 6205
Stainless steel mirror finish
The generic term “stainless steel” embraces over 100 separate rust and acid resistant steels. We manufacture our builders’ hardware utilizing a chromium-nickel steel classified as material 1.4301 under DIN 17440, similar to ASTM 304. It contains approximately 18% chromium and 8% nickel.
This alloy has proved particulary successful in the building industry.
History
In 1912, the Krupp company in Essen, Germany, patented a new material that was known as Nirosta or V2a steel. It was soon adopted for applications ranging from the construction of containers for the chemical industry and components for motorcar and aviation design to building materials and domestic appliances.
FSB supplies Stainless steel door and window fittings as standard in the following finishes:
| FSB 6204 (Standard Finish) | FSB 6205 (Special Request) |
|---|---|
| Stainless steel satin finish, comparable to US 32 D | Stainless steel mirror finish, comparable to US 32 |
Properties of Stainless steel
Stainless steel is an excellent material for door and window fittings, since its surface is extremely resistant to corrosion, knocks, scratches and abrasion and, owing to the chromium and nickel additives, needs little looking after. An invisible passive layer forms on the surface that is even said to kill bacteria.
Applications
We recommend Stainless steel for all door and window fittings subject to heavy use, in particular, in public buildings, office blocks, hospitals, motorway service areas, and public parks, at sporting venues, or on ships wherever large numbers of people regularly congregate and reliable, low-maintenance fittings are a must.
Notes on selection
When selecting and ordering door and window furniture, please read carefully the general material and technical data in this Catalogue covering terms of trade, stipulations for fire doors, specification details, design questions, bearings, product liability, handing details, spindle hole dimensions, spindle connections, door thicknesses, etc.
Care
Stainless steel fittings basically require no looking after. Smudges can be removed with a damp cloth. Outdoor fittings and those at chlorinated pools can develop what is known as flash rust after a while. This is not generated from within the metal itself and can be removed with appropriate maintenance.
