About Measurements and Fabrication Tolerances
Contents
Enclosure Size Limitations
Following are specific enclosure limitations. The main limitations are the 4'x 8' (1220mm x 2440mm) limitation imposed by our standard sheet metal stock, the 6' (1830 mm) bend length limitation imposed by press brake equipment, and the 10' (3048 mm) bend limitation imposed by the folder.
Rackmounts
Height: 1U to 9U
Depth: 2" to 46" (50.8mm to 1168mm)
U-Shape Enclosures
Height 1" to 22" (25.4mm to 558.8mm)
Width: 1" to 46" (25.4mm to 1168mm)
Depth: 1" to 46" (25.4mm to 1168mm)
Additionally, if the enclosure is more than 3"x3"x3" (76.2mm cube) the width and depth each must be at least 2" (50.8mm) greater than the height.
L-Shape Enclosures
Height 1" to 22" (25.4mm to 558.8mm)
Width: 1" to 46" (25.4mm to 1168mm)
Depth: 1" to 24" (25.4mm to 609.6mm)
Additionally, if the enclosure is more than 3"x3"x3" (76.2mm cube) the width and depth each must be at least 2" (50.8mm) greater than the height.
Flat Panels
max of 95"x 47" (2413mm x 1193.8mm)
Consolet
Height 1" to 22" (25.4mm to 558.8mm)
Width: 1" to 46" (25.4mm to 1168mm)
Depth: 1" to 46" (25.4mm to 1168mm)
Additionally, if the enclosure is more than 3"x3"x3" (76.2mm cube) the width and depth each must be at least 2" (50.8mm) greater than the height.
1U Extruded Enclosures
Width 1.5" to 23" (38.1mm to 584.2mm)
Depth 1" to 35" (25.4mm to 889.0mm)
Height 1.75" (1U)
Folded front version cannot have a thickness of more than 0.064" for front and rear.
Material Thickness Notes
- When adding self-clinching standoffs or studs to the inside, take the material thickness into account when you select the height of the fasteners, to ensure there is sufficient clearance between the fasteners and any component (such as a circuit board) on the inside of the enclosure. For example, a 0.375" standoff mounted in a 14-gauge (0.075") enclosure wall will provide only 0.300" clearance to the surface of the component, and less if the metal is thicker.
- Also take material thickness into account when aligning a connector or circuit board against the inside of the case. If connectors are mounted too close to the edge of the board, the board could get jammed into position when mounted, thus inducing stress on the board and compromising its electrical integrity.
- To ensure a proper fit, subtract both the material thickness plus 10/1000" (allowance for manufacturing variability) from the standoff height. If you are not sure about the material thickness, email sales@protocase.com with the type, size, and style (for example, aluminum U Shape 20" wide, 10" high, 15" deep). You can also measure the standoff from the inside of the case using the Measure tool.
- See also: Selecting height of self-clinching fasteners based on material thickness
Fabrication Tolerances
Whether submitting your own CAD file or a file from Designer (which provides dimensions for the metal components only), tolerances for finishes, cutouts, profiles, bends, and welding must be considered. For details see Fabrication Tolerances. For a quick reference, print our Fabrication Tolerances Diagram.
- Our CNC Milling process can cut and engrave to within tolerances of a few thousandths of an inch or less. Because finishing processes affect surface finish (and therefore part size), we do not recommend applying secondary finishes to high-tolerance parts, as the finishing process can remove enough material to put the finished part out of size tolerance. For details see CNC Milling.
- For dot peening, the positional tolerance of text is +/-0.125" on x and y. (Tighter tolerances are possible; if this is necessary, please email info@protocase.com.) For details see Permanent Marking.
- Screw thread size includes the hole diameter along with the standard screw types. For example, a thread size of "2-56 [0.07]" indicates the standard 2-56 screw type with a diameter of 0.07" for the threaded hole. The minor diameter is used along with some tolerance so that it does not bind.
Measurement Considerations for Specific Designs
- Designing enclosures for motherboard-based systems
- Creating an enclosure to mount a PCB
- Selecting height of self-clinching fasteners based on material
thickness
- When using Designer, if you need a part that is not stocked, you can add a similar part for purposes of placement and length, and use the Note tool to specify the exact part that you really want. Non-stocked parts incur additional time, and you will be informed of that cost.
- In rackmount enclosures, the chassis is not the same height as the front panel; there is a 1/8" (.125") gap on the top and bottom in order to make room for protruding screw heads. If you need more room to fit a component into the case, choose Full Height Chassis in the template dialog. This causes the screws to be countersunk and the chassis to be the full height of the front panel.
