Types of Aluminum Exit Signs, What To Look For. There are many different types of aluminum exit signs but all them share a few qualities: durability and great possibility for cool finishes.Aluminum exit signs can be formed via die-casting, sand casting, extrusion, stamping, precision milling, water-jetting, or folding. Depending on the process the finishes bear different characteristics with trade-offs. This article will cover the popular models of aluminum exit signs and help you become more informed about the features and benefits you'll need to consider when selecting signs for your emergency egress system.Die-Cast Aluminum Exit SignsThe Die-casted aluminum exit sign's surface is pitted when unfinished. The surface's smoothness is unpredictable due to the escaping hot gases during the forming process. This realty makes die-casted aluminum exit signs an unlikely mass-produceable candidate for shiny finishes such as brass plating. The surface needs to be either brushed or power-coated to be presentable. The ease and speed of the die-casting process produces an economical product that is especially well complimented by the brushed finished effect, especially on the faceplates and frames. The outcome is like a combed metal with flowing strokes that when covered in a clear coat can really be spectacular. The marvel of the die-casting process with respect to the exit sign's face plate is that although the aluminum remains hard and durable, the faceplate is still capable of having arrow "knock-outs" configurable infield. This is made possible by arrow-shaped perforations added just beneath the back side surface. They are called "Knock Outs" for a reason; you need to use a blunt object to knock the arrows out of the surface. Once the arrows are removed, they cannot be replaced. A balance is achieved in cost, configurability, durability, and decor. View examples of Aluminum Exit SignsExtruded Aluminum Exit Signs You may already be familiar with extruded aluminum as it is used widely in the creation of common goods you may already have in your home such as picture frames and shower door frames, Extruded aluminum is very popular in exit signs for its low cost and accuracy in reproduction. The process involves running molten aluminum through the openings of a pre-formed shape to create long single formed pieces which are then cut into smaller lengths for easy transport. The molten aluminum takes the form of the master shape as it is forcibly pushed through the opening. The aluminum is cooled to keep the shape and additional processes may be added in line such as a brushing wheel, polish wheel, or cutting at certain intervals. In exit signs, extruded aluminum is used in the creation of housings, trim plates, and frames. The pieces are light weight, durable, and due to the smooth surface, excellent for many times of finishes including plating, anodizing, power-coating, and brushing.Here are examples of extrusions used in exit signs. Edge-lit exit sign Photoluminescent Exit Sign Frames Sheet Aluminum Exit Signs Using aluminum sheets in signs is very common, perhaps the most popular example is a stop sign. The sheets are not very thick, they are smooth and are very durable. Aluminum sheets are used as "blanks" which are formed by either metal stamping, laser cutting, water jetting or similar processes. In exit signs, the blanks serve as the subsurface upon which glow-in-the-dark materials are painted or as inserts in the exit face plate stencil or as a decorative piece covering the back of the sign when the sign is top or side mounted. Because the sheets are very smooth, they are able to receive many finishes, however, they are prone to bending if enough persistent stress is placed upon them. For this reason, the sheets are typically reinforced by framing. Sheet Aluminum Exit Signs are capable of being back-mounted without a frame and located above a door and are most durable when installed against a wall. The low profile makes the back mounted versions ideal for low level exit signs, that is, exit signs installed approximately 18" above the floor. Caution should be exercised though when installing these signs at low levels because the edges can be very sharp. Therefore, it is strongly advised that the low level approved aluminum exit signs be framed. View our Low Level Approved Exit Signs Milled Aluminum Exit Signs Milling aluminum exit signs can yield great details and precision. The milling starts with blocks of high quality aluminum. We can create custom designs and shorter runs using this method, however, setup costs, lower production counts, and the cost of materials makes exit signs created using this process the most expensive. The results however are unmatched. The surfaces are as smooth as glass, capable of anodizing, plating, and brushing with showroom quality finishes. The milled aluminum signs tend to be heavier as the materials are very dense, however, they are extremely durable. The benefit to this process is that there is superior control of the final product. The downside is cost. A compilation of the most common Fire Safety Violations and how to avoid them.