Last updated on August 28th, 2026 at 09:36 am
A formed precision sheet metal part can look completely reasonable in CAD and still be impossible to manufacture on a press brake.
The problem is often not the bend angle itself. It is tool access and clearance. As each bend is made, the partially formed part must clear the press brake punch, die, ram, and surrounding tooling.
Bend sequence matters too. A bend that is easy to make when the part is flat may become difficult or impossible after another flange has already been formed.
Most fabrication shops rely on standard press brake tooling to manufacture formed sheet metal parts efficiently. When the geometry cannot be reached or cleared with available tooling, the fabricator may need to change the tooling, modify the bend sequence, redesign the part, split it into multiple components, or no-quote the project.
At Approved Sheet Metal, our forming experts review difficult parts for practical ways to maintain the design intent while making the geometry manufacturable.
How Press Brake Tooling Clearance Affects Part Design
During press brake forming, the punch must reach the bend line while the rest of the part remains clear of the tooling and machine throughout the bend.
Geometry that commonly creates press brake clearance problems includes:
- Deep boxes and enclosures
- Tall return flanges
- Narrow channels
- Opposing flanges
- Back bends
- Bends located deep inside the part
- Closed or nearly closed geometry
- Multiple bends that restrict access to later bends
For every bend, there are two basic questions: Can the punch reach the bend line, and can the rest of the part clear the tooling throughout the forming operation?
If the answer to either question is no, the geometry may need a different tool, bend sequence, or design approach.
Standard Press Brake Tooling at ASM
Approved Sheet Metal maintains a range of press brake tooling for common sheet metal forming requirements, including:
- 90-degree bending for 27-10 gauge material
- 90-degree bending with thin-tip punches
- 90-degree bending with narrow punches
- 90-degree bending with thin-tip gooseneck punches
- 90-degree bending with gooseneck punches
- 90-degree sash bending
Different punch profiles provide different types of access to the bend line. A narrow or thin-tip punch may provide clearance where a larger standard punch cannot.
A gooseneck punch provides additional clearance for previously formed flanges or return bends that would interfere with a straight punch. This makes gooseneck tooling particularly useful when the geometry of the part begins wrapping back toward the tooling.
Gooseneck tooling does not eliminate every interference problem, however. Flange height, channel width, bend location, material thickness, tooling geometry, and bend sequence still determine whether the part can actually be formed.
Offsets, Hems, and Large-Radius Bends
Some sheet metal features require tooling or forming methods beyond a standard 90-degree bend.
Offset Bends
ASM can use dedicated offset tooling when the offset height and geometry need to be controlled together.
When the offset height is the primary requirement and the exact intermediate angle has more flexibility, ASM may be able to create a “lazy offset” using sequential bends instead.
This can be particularly useful for prototype and low-volume fabrication because it may eliminate the cost and lead time associated with dedicated tooling.
Hems
For parts requiring sheet metal hems, ASM has dedicated hem tooling.
Hem manufacturability still depends on the material, thickness, hem style, surrounding geometry, and clearance available during the forming sequence.
Large-Radius Bends
Large-radius bends do not always require dedicated radius tooling.
Depending on the radius, material, thickness, and geometry, ASM may be able to form the radius in one operation or use bump forming.
Bump forming creates a larger-radius feature through a series of closely spaced incremental bends. For prototype and low-volume parts, this can provide a practical alternative to purchasing dedicated tooling for a specific radius.
Finally, we have gusset tooling for adding gussets to bent sheet metal parts.
Examples of Non-Manufacturable Formed Parts
Deep boxes can also be impossible to form using conventional tooling. In this example, the sides are too high and the distance between the sides is too narrow, which would cause the part to crash into the press brake.
3 Options for Projects Requiring Non-Standard Press Brake Tooling
So, what happens when we get an RFQ for a part that we can’t make with standard press brake tooling? We find a solution to avoid the dreaded no-quote. Here are three pathways forward at ASM:
Custom tooling
While custom tooling is an option, we consider it almost as bad as no-quoting. Why? Custom tooling adds considerable cost and time to a project, which is hard to justify for prototypes or low-volume parts. Our team will always try to find alternative solutions before suggesting custom tooling. But if you decide that’s the right path, we’ll support your plan and work with you to get the proper tooling for your project.
Cut and weld
We’re experts at cutting and welding sheet metal parts and offer various in-house welding capabilities, including MIG, TIG, and spot welding. When a sheet metal part is too big for our standard equipment and tooling, we can separate it and weld the pieces together into a final part.
Update the design
The most efficient solution is often to update the design so the part can be made using standard tooling. You may need to sacrifice certain aesthetic preferences, such as rounded features. But if you have some degree of flexibility in your design, minor changes can save you time and money.
Example of an Updated Design for a Formed Part
We love to help our customers improve their designs and are always happy to collaborate with you.
For example, this project posed a small challenge: the part walls exceeded our equipment depth capacity, which would cause the part to crash into the press brake during the bending process. We came up with two alternative options.
Material Considerations in Forming
Material selection for sheet metal fabrication significantly impacts formability, tooling choices, and overall part performance. Engineers must account for factors like material hardness, thickness, and elongation properties to ensure parts can be efficiently formed without defects.
1. Common Sheet Metal Materials and Their Formability
| Material | Formability | Key Considerations |
|---|---|---|
| Aluminum (5052, 6061) | Good (5052), Poor (6061) | 6061 is prone to cracking when bent; 5052 is preferred for formed parts. |
| Mild Steel (CRS, HRS) | Excellent | Can be easily formed but may require additional corrosion protection. |
| Stainless Steel (304, 316) | Moderate to Poor | High springback; requires increased bend radii and force. |
| Copper/Brass | Excellent | Soft and ductile; often used in electrical applications. |
2. Key Material Properties Affecting Forming
- Ductility & Elongation: Determines how much a material can be stretched or bent without cracking.
- Yield Strength: Higher strength materials require more force to form and may exhibit greater springback.
- Thickness: Thicker materials require larger bend radii and may need specialized tooling.
- Grain Direction: Forming perpendicular to the grain structure reduces cracking risk, especially in stainless steel.
3. Strategies for Improved Formability
- Choose the Right Alloy: For aluminum parts that require forming, 5052 is a better choice than 6061.
- Increase Bend Radii: Tight bends increase the risk of cracking, especially in high-strength materials.
- Annealing or Stress-Relieving: Some materials (e.g., stainless steel) benefit from heat treatment before forming.
- Utilize Pre-Finished Materials: Pre-anodized or pre-plated materials can reduce post-processing steps.
Whether you need custom tooling, cutting and welding, or design updates, our team is here to help you get your sheet metal parts fast. Our goal is to maintain your design intent while efficiently moving your part through our shop.
Let us show you what our team of sheet metal fabrication experts can do for you. Request a quote for your precision sheet metal parts today.
Recommended Default Sheet Metal Tolerances
| DIM | Tolerance (MM) | Tolerance (Inches) | Description |
| A | ± 0.13 | ± 0.005 | Sheared Edge to Hole |
| B | ± 0.13 | ± 0.005 | 2 Holes on One Surface |
| C | ± 0.25 | ± 0.010 | Formed Edge to Hole |
| D* | ± 0.76 | ± 0.030 | Holes Across 2 Bends |
| E* | ± 0.76 | ± 0.030 | Holes Across 4 Bends |
| F | ± 0.25 | ± 0.010 | Sheared Edge to Bend |
| G | ± 0.38 | ± 0.015 | Across 2 Bends |
| H* | ± 0.76 | ± 0.030 | Formed Part |
* Dimensions D, E and H are not recommended forms of dimensioning
These tolerances are recommended and best practices. We can obtain tighter tolerances (depending on part geometry/ construction), contact us for more information Download PDF
Standard Press Brake Tooling FAQ
Why might the design for my precision sheet metal part not be manufacturable at many metal fabrication shops?
Most metal fabrication shops rely on standard press brake tooling to fabricate formed sheet metal parts efficiently. If your design requires non-standard tooling, shops may not be able to manufacture it and may decline to quote the part.
What kind of standard press brake tooling is available for forming sheet metal parts?
The standard press brake tooling available at Approved Sheet Metal includes options such as 90-degree bending for different gauge ranges, thin tip punches, narrow punches, gooseneck punches, and sash bending. Custom offset tooling and hem tooling are also available for specific requirements.
What options are available for projects that require non-standard press brake tooling?
When faced with a project that cannot be made using standard press brake tooling, there are three pathways forward at Approved Sheet Metal:
- Custom tooling, although it adds cost and time to the project and is typically suggested as a last resort.
- Cut and weld, where the sheet metal parts are cut and welded together using various techniques like MIG, TIG, or spot welding.
- Updating the design to make it compatible with standard tooling, which is often the most efficient solution and can save time and money.
Can Approved Sheet Metal help me update my design to make it manufacturable with standard tooling?
Yes, Approved Sheet Metal is happy to collaborate with customers to improve their designs. They have experience in updating designs to make them compatible with standard tooling, even if it requires sacrificing certain aesthetic preferences. Minor changes in the design can save time and money in the fabrication process.
How can I get assistance from Approved Sheet Metal for my precision sheet metal parts?
You can request a quote from Approved Sheet Metal for your precision sheet metal parts. Their team of sheet metal fabrication experts is always available to help you. Whether you need custom tooling, cutting and welding, or assistance in updating your design, their goal is to efficiently move your part through the shop while maintaining your design intent.