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Die Casting Secrets: How to Calculate the Clamping Force


    As a die casting dies designer; Always need to Calculate the Clamping Force. as you know, when they Run DFM report to customer. they need to know the tonnage of the die casting machine; and the size of the die casting machine. Gate and Plunger size. also know the injection time. However, how they exactly calculate the machine tonnage for die casting parts? how they know the high pressure die casting machine tonnage through analyse the parts size? in this article, we will explain how to calculate the clamping force for die casting parts.

    Calculate the clamping force of high pressure die casting machine

    What is the Clamping force?

    Clamping force is the force which applied to the mold by die casting machine. which is overcome the Separating force of the molten in the cavity during casting. When the Molten metal is injected into the mold cavity with high pressure and speed, so die casting machine clamping unit need provide sufficient “clamping force”to keep the mold from being opened.

    Casting Pressure specific

    The Casting pressure applied by plunger to push the molten metal into the die. different requirement of parts use different casting pressure. see below.

    1. Standard die casting parts: 600 kg/cm2
    2. Higher Standard die Casting parts: 600~800 kg/cm2
    3. Pressure-resistant die casting parts: 800 kg/cm2

    Projection area

    This refers to the area surrounded by the outer contour line of the shadow of the die-cast product.

    Die casting Projection area include below.

    1. die casting parts max projection area
    2. Gate+ Runner Projection area
    3. Overflow + Slug Projection area.

    Normally, (Gate+Runner+Slider+overflow+slug) projection area= 2 times die casting pats projection area.

    Clamping force Formula

    Till now, we already understand the casting pressure and projection area, then, we will easy to get the die casting machine tonnage by below formula.

    F= Casting Pressure* Projection area


    Here below lets run a example to run the formula to calculate die casting machine tonnage.

    Clamping force of die casting parts

    Product Basic Info

    Part Dimension: 100*120*32mm Material : ADC12

    Wall Thickness: 5mm Shrinkage: 1.005

    hence, we can get below info.

    Part projection area= 100*120/100=120 cm2

    Casting Pressure: 800 kg/cm2

    Clamping force=800*120*2/1000=192 ton

    Above all, we can know we need around 192 ton clamping force to produce this parts. means we can use 200 ton die casting machine.


    that is not too difficult, right? will be easier if you know the principle; here it is. we are professional die casting supplier, Main offer aluminium, zinc and magnesium alloy die casting, also multi-slider die casting. please contact us if you have die casting project need to develop.


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