Design Guidelines: Sheet Metal Fabrication

Our basic guidelines for sheet metal fabrication include important design considerations to help improve part manufacturability, enhance cosmetic appearance, and reduce overall production time.


Size

Maximum Dimensions
  US Metric
SIZE 39 in. x 47 in. 990.6mm x 1,193.8mm
BEND LENGTH 47 in. 1,193.8mm

Minimum Dimensions
  US Metric
FLAT PART 0.250 in. x 0.250 in. 6.35mm x 6.35mm
FORMED PART 0.500 in. x 0.500 in. 12.7mm x 12.7mm

Tolerances

Single Surface
  US Metric
Bends +/- 1 degree +/- 1 degree
Offsets +/- 0.012 in. +/- 0.304mm
Hole Diameters +/- 0.005 in. +/- 0.127mm
Edge to edge/hole; hole to hole +/- 0.005 in. +/- 0.127mm
Hardware to edge/hole +/- 0.010 in. +/- 0.254mm
Hardware to hardware +/- 0.015 in. +/- 0.381mm
Bend to edge +/- 0.010 in. +/- 0.254mm
Bend to hole/hardware/bend +/- 0.015 in. +/- 0.381mm

Multiple Surface
  US Metric
Features separated by two or more bends +/- 0.030 in. +/- 0.762mm
Tolerances vary on depending on part feature such as bends, offsets, holes, and inserted hardware.

Tolerances vary on depending on part feature such as bends, offsets, holes, and inserted hardware.



Booklet

Sheet Metal Surface Finish Guide

Check out our sheet metal guide for a quick snapshot of our Standard and Cosmetic finishing options available for various sheet metal materials.

Download Guide

Materials

  • Aluminum (1)
  • Brass (2)
  • Copper (3)
  • Stainless Steel (4)
  • Steel: CR Non-treated (5)
  • Steel: CR Galvanneal and CR Galvanized (6)

View Materials


Sheet Metal Material Thickness Chart

Because sheet metal parts are manufactured from a single sheet of metal, the part must maintain uniform wall thickness. Sheet metal thickness ranges from 0.024 in. (0.609mm) to 0.250 in. (6.35mm).

 

Steel Stainless Steel Aluminum Copper Brass
CRS/HRPO Galvanneal Galvanized 304-2B 304 #4 316-2B 5052-H32 6061-T6 C1010 C1100 C260
0.024 0.024 0.024 0.024 0.024 0.024 0.025 0.025   0.025 0.025
0.029 0.029 0.029 0.03 0.03 0.03 0.032 0.032 0.032 0.032 0.032
0.036 0.036 0.036 0.036 0.036 0.036          
0.042           0.04 0.04 0.04 0.04 0.04
0.047 0.047 0.047 0.048 0.048 0.048 0.05 0.05 0.05 0.05 0.05
0.059 0.059 0.059 0.059 0.059 0.059 0.063 0.063 0.063 0.063 0.063
0.074 0.074 0.074 0.074 0.074 0.074 0.080 0.080 0.080 0.80 0.080
0.089 0.089 0.089 0.089 0.089 0.089 0.093 0.093 0.093 0.093 0.093
0.104 0.104 0.104 0.105 0.105 0.105 0.10 0.10      
0.119 0.119 0.119 0.119 0.119 0.119 0.125 0.125 0.125 0.125 0.125
0.134 0.134 0.134 0.134 0.134 0.134          
0.160           0.160 0.160      
0.179     0.1875     0.190 0.190      
0.250     0.250     0.250 0.250      

 

sheet metal thickness depth

Because sheet metal parts are manufactured from a single sheet of metal, the part must maintain uniform wall thickness.

Sheet metal thickness ranges from .0.024 in. (0.609mm) to 0.250 in. (6.35mm).

Sheet metal thickness ranges from .0.024 in. (0.609mm) to 0.250 in. (6.35mm).

Z Frame

Want to create designs that convert flat sheets of metal into fully formed three-dimensional parts? Incorporating everything from countersinks and punch-outs to powder coating and silk screening, our functional design aid will show you the way. The Z Frame explores fabrication processes unique to sheet metal and design elements that will improve the structural integrity and appearance of your parts. It even doubles as a desktop organizer.

Get Z Frame

Finishing

We offer welded assemblies, standard mill, edge breaking, and orbital-sanded surface finishes along with a number of additional sheet metal finishing options:

  • Seam, tack, and stitch welding
  • Hardware insertion and riveting: Standard PEM sheet metal hardware
  • Powder coating: A variety of powder coat paint colors available in textured and non-textured finish, including RAL colors. View our powder coat options here
  • Silk screening (one- and two-color): Colors mixed to closely match most Pantone numbers
  • Assemblies: POP-riveted and welded
  • Plating: Anodize, chromate, zinc, and passivate
In-house powder coating is available to streamline production, and parts are powder coated in compliance with government regulations.

In-house powder coating is available to streamline production, and parts are powder coated in compliance with government regulations.


Bend Radius

We hold a +/- 1 degree tolerance on all bend angles. We offer a wide range of common bend radii, but our standard options are .030 (.762mm), .060 (1.524mm), .090 (2.286mm), .120 (3.048mm). These four bend radii tooling choices are available in a 3 day lead time. Flange length must be at least 4 times the material thickness.

It is recommended to use the same radii across all bends, and flange length must be at least 4 times the material thickness.


sheet metal bend

Hems

We form both open and closed hems. The tolerance of a hem is dependent upon the hem’s radius, material thickness, and features near the hem.

We recommend that the minimum inside diameter equals the material thickness, and a hem return length of 6x material thickness.

 


Offsets

Offsets are used to create Z-shaped profiles in sheet metal parts. We offset height tolerance at +/-0.012 in.  (0.304mm) from top of sheet to top of form and recommend an offset of 0.030 in. (0.762mm).

Additional standard options include: available 0.060 in. (1.524mm), 0.093 in. (2.362mm), 0.125 in. (3.175mm), 0.187 in. (4.749mm), 0.213 in. (5.410mm), 0.250 in. (6.35mm), 0.281 in. (7.137mm), and 0.312 in. (7.924mm).


sheet metal offset illustration

Holes and Slots

Holes and slots should be a minimum of material thickness in diameter. If a material is 0.036 in. (0.914mm) or thinner, the hole should be 0.062 in. (1.574mm) from the material edge; if the material is thicker than 0.036 in. (0.914mm), the hole should be at least 0.125 in. (3.175mm) from the material edge to avoid distortion. If hardware inserts are required, the spacing should be according to manufacturer’s specifications.



Notches and Tabs

Notches must be at least the material’s thickness or 0.04 in. (1.016mm), whichever is greater, and can be no longer than 5 times its width. Tabs must be at least 2 times the material’s thickness or 0.126 in. (3.200mm), whichever is greater, and can be no longer than 5 times its width.


 


sheet metal notches and tabs illustration

Countersinks

We offer both machined and formed countersinks—conical holes cut into a manufactured object allowing a screw, nail, or bolt to be inserted flush with the surface.

We recommend the major diameters of countersinks measure between 0.090 in. (2.286mm) and 0.500 in. (12.7mm) using one of the following standard angles: 82°, 90°, 100°, and 120°.

Tolerance for formed countersink major diameter is +/- 0.010 in. (0.254mm).


sheet metal countersink illustration