The dimensional tolerance of a custom fastener depends on the manufacturing process, product design, material, dimensions, and specific application requirements. At HETAI, we select the appropriate manufacturing process based on the required accuracy, product geometry, production quantity, and performance requirements.

For different manufacturing processes, HETAI can provide different levels of dimensional accuracy, from standard production tolerances to high-precision machining and grinding.

What Tolerance Can HETAI Achieve?

At HETAI, the achievable tolerance for custom fasteners depends on the manufacturing process, product design, material, dimensions, and specific application requirements.

For our standard cold-forged fasteners, HETAI can generally achieve dimensional tolerances of approximately ±0.01 mm under suitable production conditions. Cold forging is widely used for high-volume fastener production because it provides good production efficiency, consistent dimensions, and competitive manufacturing costs.

For CNC-machined custom fasteners, we can typically control dimensional tolerances to approximately ±0.005 mm, depending on the part geometry, material, size, and machining requirements. CNC turning and milling provide greater flexibility for complex geometries, special dimensions, low-volume production, prototypes, and precision custom fasteners.

For precision hardware components processed through grinding, HETAI can achieve even tighter dimensional tolerances. For suitable features and applications, precision levels can be controlled to approximately ±0.002 mm. Grinding is particularly useful when extremely precise dimensions, surface finish, or close dimensional control is required.

Why Does Tolerance Depend on the Manufacturing Process?

Different manufacturing processes have different capabilities and limitations.

Cold forging forms the fastener through controlled plastic deformation. It is highly efficient for producing large quantities of similar parts, but the achievable tolerance depends on the material, tooling, part geometry, forming stages, and production conditions.

CNC machining removes material to produce the required dimensions and geometry. It provides greater flexibility and can achieve tighter tolerances for many custom fasteners, especially when the product requires special features that are difficult to produce through conventional forming.

Grinding can provide an even higher level of dimensional control for suitable features. However, it is generally used as a precision finishing process rather than the primary manufacturing method for every fastener.

Does Every Feature Need the Same Tolerance?

No. A custom fastener does not necessarily need the same tolerance for every dimension.

For example, a critical shaft diameter or mating surface may require a very tight tolerance, while a non-critical overall length or head dimension may allow a wider tolerance. Applying unnecessarily tight tolerances to every feature can increase machining time and manufacturing costs without improving the actual performance of the product.

Therefore, HETAI recommends specifying tighter tolerances only where they are functionally necessary.

What Factors Affect Custom Fastener Tolerance?

Several factors can influence the final dimensional accuracy, including:

• Manufacturing process
• Material type and hardness
• Part size and geometry
• Thread specifications
• Required surface finish
• Heat treatment
• Surface treatment
• Tooling and equipment
• Production quantity
• Measurement methods
• Actual application requirements

For this reason, tolerance should always be evaluated together with the complete product design rather than considered as a single number.

HETAI Precision Manufacturing Capability

At HETAI, we manufacture custom fasteners and precision hardware according to customer drawings, samples, and technical specifications.

Depending on the application, our manufacturing capabilities can generally include approximately ±0.01 mm for suitable cold-forged fasteners, ±0.005 mm for suitable CNC-machined custom fasteners, and approximately ±0.002 mm for suitable precision features processed through grinding.

These values are reference capabilities rather than universal guarantees. The actual achievable tolerance must be evaluated according to the specific material, dimensions, geometry, process, and application requirements.

Our goal is to achieve the right level of precision for each application, while balancing dimensional accuracy, product performance, manufacturing efficiency, and cost.