For many years now, the die-casting manufacturing process still is at the top of the game when it comes to producing different metal parts. This process remains the go-to option because of the various aspects among them being the ability to maintain concrete tolerances. What are tolerances and which types are there in die casting?
In layman’s language, tolerances refer to the allowed variations in the measurements of a casting. Assume, you are producing a certain part and of course, you have the desired dimensions. Now, in most cases, the dimensions produced will not be as exact as you want them, they will vary but still be within the specified tolerance limits.
These tolerances are important in ensuring that the casting tolerances meet the functional requirements. At Sunrise Metal, we know that die-casting tolerances are vital and we’ve got you covered! Our team of qualified experts determines the appropriate tolerances for your casting and also, you are equipped with the right machines to produce castings with tight tolerances.
The Main Types of Tolerances in Die Castings
Now that you know what die-casting tolerances are, it is important to know the various types available. Here are the main types of die-casting tolerances:
Linear Casting Tolerances
Linear casting tolerances focus on the allowed deviation in the dimensions of casted parts. This kind of casting tolerance sets a limit for the dimensional shift as the molten material fills a mold, cools, and solidifies. This process can cause a shift either upward or downward in the dimension which can be a result of temperature fluctuation, and mold deformities.
With linear casting tolerance the tolerance of + or – 1mm is set for a 100mm component. This means that the acceptable length and that which will be ideal for the product to perform its functions well will be 99 to 101mm.
Tolerances for Flatness
Tolerances for flatness are used on a single surface or a group of surfaces on a part. Flatness tolerance is shown by a flatness symbol resembling a square with two parallel lines inside. This is then followed by a tolerance value which represents the maximum allowed variation from a perfectly flat surface on a manufactured part.
Tolerances for flatness ensure that even if the surface of the manufactured part is not perfectly flat, it is still within acceptable limits. Normally, the deviation from the desired flatness is not measured against the reference but on the surface itself. It is vital to maintain the required flatness so that the parts can function without oscillating.
Die Casting Tolerances for Parting Lines
Die casting tolerance for parting lines refers to the allowable maximum amount of die separation for the end product to meet specified requirements for it to function well, have a proper shape, and fit well. Think of parting line tolerance as the amount by which a mold can open up when the material is flowing between the two halves of the mold. This is what we call the projected area.
Typically, a fully closed mold has no separation. Therefore, any additional material or pressure will cause it to open slightly and this will result in a thicker product than the one desired.
Die casting tolerances for parting lines are vital in ensuring that the parts manufactured are precise. Understanding and maintaining die-casting tolerances for parting lines is important to ensure the consistency, quality, and functionality of the die-cast products.
Tolerances for Moving Die Parts
Tolerances for moving die parts refer to the acceptable limits within which moving components of a die can operate. During die casting, molds often have movable sections that allow for the formation of complex parts. Now, the moving components should align and operate accurately within the assembly mold.
The tolerances refer to how much the parts can deviate from their specified dimensions but still be able to function well. If these parts move too much or too little, then the final product might be defective. It is therefore vital to set and maintain strict tolerances to ensure consistent product quality and efficient mold operations.
Minimum Tolerances in Aluminum Die Casting
As said earlier, there are various die-casting tolerances and each has an allowable tolerance. This can vary depending on the size and complexity of the casting. The minimum tolerances for aluminum die casting are as follows:
Linear Casting Tolerances
Aluminum die casting needs to be as precise as possible. The allowable deviation for linear dimensions is +/-0.12mm which is about +/-0.005 inches
Tolerances for Flatness
It is vital to ensure that the aluminum casting is almost flat. The acceptable variation for flatness is +/-0.025mm or +/-0.001 inches.
Die Casting Tolerances for Parting Lines
The aluminum die-casting tolerance for parting lines is also vital to consider. However, the permissible deviation is about +/-0.25mm which is equal to +/-0.01 inches.
Tolerances for Moving Die Parts
For movable components within the mold, the allowable tolerance is set at +/-0.005mm which is about +/-0.002 inches.
Conclusion
We cannot overlook the importance of tolerances on die casting. The different types of tolerances available should be put into consideration during the die-casting process for aluminum. This way, you can produce a part that is fit to function well even when there is a slight variation from the needed measurement. Combining a high-quality die-casting process, using an expert die caster, incorporating good materials, and inspecting the casting carefully, you can be sure to get the die castings that meet the required tolerances.
That said, getting a qualified die-casting manufacturer in China like Sunrise Metal will give you peace of mind that you will get castings with tight tolerances. We ensure that what you order from us is what you get. Contact us for high-quality casting today!