Design Guidelines: Sheet Metal Fabrication

Design guidelines for sheet metal fabrication focus on optimizing material usage, minimizing waste, ensuring ease of forming and bending, and maintaining structural integrity while considering factors like tolerances, material thickness, and accessibility for machining or assembly.

Size

Maximum Dimensions

	Metric	US
Size	990.6mm x 1,193.8mm	39 in. x 47 in.
Bend Length	1,193.8mm	47 in.

Minimum Dimensions

	Metric	US
Formed Part	12.7mm x 12.7mm	0.500 in. x 0.500 in.
Flat Part	6.35mm x 6.35mm	0.250 in. x 0.250 in.

Tolerances

Single Surface

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

Multiple Surface

	Metric	US
Features separated by two or more bends	+/- 0.762mm	+/- 0.030 in.

Guide for Sheet Metal Surface Finish

Explore our sheet metal guide for an overview of the standard and cosmetic finishing options available for different sheet metal materials.

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Materials

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

Sheet Metal Material Thickness Range

\Sheet metal parts are formed from a single sheet of metal, requiring a uniform wall thickness throughout. Thickness typically ranges from 0.024 inches (0.609 mm) to 0.250 inches (6.35 mm).

Steel			Stainless			Aluminum		Copper		Brass
CRS/HRPO*	Galvanneal	Galvanized	304-2B	304-#4	316-2B	5052-H32	6061-T6	C101	C110	C260
0.024	0.028	0.028	0.024	0.024	0.024	0.025	0.025		0.025	0.025
0.030	0.034	0.034	0.029	0.029	0.029	0.032	0.032	0.032	0.032	0.032
0.036	0.040	0.040	0.036	0.036	0.036
0.042						0.040	0.040	0.040	0.040	0.040
0.048	0.052	0.052	0.048	0.048	0.048	0.050	0.050	0.050	0.050	0.050
0.060	0.063	0.063	0.060	0.060	0.060	0.063	0.063	0.064	0.062	0.063
0.075	0.079	0.079	0.075	0.075	0.075	0.080	0.080	0.080	0.080	0.080
0.090	0.093	0.093	0.090	0.090	0.090	0.090	0.090	0.093	0.093	0.093
0.105	0.108	0.108	0.105	0.105	0.105	0.100	0.100
0.120	0.123	0.123	0.120	0.120	0.120	0.125	0.125	0.125	0.125	0.125
0.135*	0.138	0.138	0.135	0.134	0.135
0.164*			0.165			0.160	0.160
0.179*			0.187			0.190	0.190
0.239*			0.250			0.250	0.250

*These thicknesses are available as Hot Rolled, Pickled & Oiled (HRPO) only

Z Frame

Looking to transform flat metal sheets into fully formed three-dimensional parts? Our functional design aid, featuring countersinks, punch-outs, powder coating, and silk screening, provides all the guidance you need. The Z Frame highlights sheet metal fabrication processes and key design elements to enhance the structural integrity and aesthetics of your parts—and it even doubles as a handy desktop organizer.

Custom Z-Frame Quote

Surface Finishing

We provide a wide range of sheet metal finishing options, including welded assemblies, edge breaking, standard mill finishes, and orbital-sanded surfaces:

Powder Coating: Available in textured and non-textured finishes, with a variety of colors, including RAL options.
Plating: Includes anodizing, chromating, zinc coating, and passivation.
Welding: Seam, tack, and stitch welding for durable assemblies.
Hardware Insertion and Riveting: Standard PEM hardware and POP-riveted assemblies.
Silk Screening: One- and two-color options with colors matched closely to most Pantone numbers.
Assemblies: POP-riveted and welded for added strength and functionality.

fabricated assemblies metal part different types of surface finishing

KingStar Mold’s Capabilities

Bend Radius

We maintain a tolerance of +/- 1 degree on all bend angles and offer a variety of common bend radii. Our standard options include 0.030 inches (0.762 mm), 0.060 inches (1.524 mm), 0.090 inches (2.286 mm), and 0.120 inches (3.048 mm), with tooling available on a 3-day lead time. For optimal results, it is advised to use consistent radii across all bends. Additionally, the minimum flange length for sheet metal parts must be at least four times the material thickness.

Hems

We produce both open and closed hems, with tolerances influenced by the hem’s radius, material thickness, and nearby features. For best results, we recommend a minimum inside diameter equal to the material thickness and a hem return length of six times the material thickness.

Offsets

Offsets are used to create Z-shaped profiles in sheet metal parts, with a height tolerance of +/- 0.012 inches (0.304 mm) from the top of the sheet to the top of the form. We recommend a standard offset of 0.030 inches (0.762 mm).

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

Holes and Slots

Holes and slots should have a minimum diameter equal to the material thickness. For materials 0.036 inches (0.914 mm) or thinner, holes should be at least 0.062 inches (1.574 mm) from the material edge. For thicker materials, the minimum distance increases to 0.125 inches (3.175 mm) to prevent distortion. If hardware inserts are needed, spacing should follow the manufacturer’s specifications.

Notches and Tabs

Notches should be at least the material thickness or 0.04 inches (1.016 mm), whichever is greater, and their length must not exceed five times their width. Tabs must measure at least twice the material thickness or 0.126 inches (3.200 mm), whichever is greater, with a maximum length of five times their width.

Countersinks

We provide both machined and formed countersinks, which are conical holes designed to allow screws, nails, or bolts to sit flush with the surface.

For optimal results, we recommend major diameters between 0.090 inches (2.286 mm) and 0.500 inches (12.7 mm) with standard angles of 82°, 90°, 100°, or 120°. The tolerance for the major diameter of formed countersinks is +/- 0.010 inches (0.254 mm).

What is the recommended minimum flange length for sheet metal parts?webadmin2025-01-17T02:16:02+00:00

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