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drawing of a countersunk DIN 965 M4

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5 commentaires

  • Jacant

    An M4 DIN 965 has a 90° chamfer. So looking at  the profile it would seem that you need a 3.5 mm hole.

     
    A chamfer is automatically formed with a 90° angle. This can be changed after it is made by altering the vertical or horizontal pull handles and using the 'angle' option. Only if the original chamfer does not go through the thickness of material.

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  • tab...

    I'd make the hole 4.5 for a M4 screw in a normal thickness panel, however, at 2mm, it isn't as thick as the screw head  so the screw head will slightly extend below the plate thickness.

    Countersunk screw recesses are always toleranced to ensure the screw head top is below the material top - it's known as 'sub-flush'.

    The max diameter across the Din 965 screw top is 7.5mm but there is also the k dimension , or head height of 2.2mm max. Also, the maximum diameter isn't stated as the 'maximum theoretical diameter',  the max head diameter referenced to the cone angle, there is a small face before the cone starts.

    Design should always make the screw head sub-flush, say by making the countersunk dia 8mm or more!  ( sub-flush 0.25mm minimum is common) The screw head bottom will protrude out by 0.45mm ( 2- 2.2-0.25 = -.45 ) as a nominal by example here only.

    There can be a wide variance in screw head manufacture and on a thin panel i would advise getting a sample screw otherwise expect for a surprise !

    If you are making manufacturing drawings for something real, what i say is only advice. Get a sample screw or tolerance for a wide divergence of screw manufacture.

     

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  • augustin ramel

    Thank you for your answer!

     

    I worked alone first yesterday and found some information...

    But Tim, I understand that a 2mm panel is too thin for a M4 DIN965 screw? I need a minimum of 2.2mm?

    I drew hole like hereunder. larger diametre is 7.5 but as I understand it's better to make a hole of 8mm?

     

    I have done the small face before the beginning of the angle, 0.5mm.

    I use a CAO of the screw obtain on the manufacturer, maybe it still better to have screws to verify the dimensions?

    I'm still wondering how to do easily this kind of drawing. For this time, I have done a representation of the hole needed and use the combine tool :

     

    Have a good day,

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  • Jacant

    Once you have drawn the correct size hole you can 'Move' this feature with the CTRL key to create copies.

     

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  • tab...

    Hi.

    There are smaller sizes than M4 such as M3.5, M3, M2.5, M2. Always check stock of odd sizes like M3.5. Having standards does not ensure parts availability.

    If the plate is too thin for the screw head body, there will be a sharp hole edge that will be rough and not round. my advice is always have a distinct hole diameter - even if it's wall ( height) is small, say 0.2 / 0.3 minimum and the more the better.

    In this example of screw to ISO 14581 i have found this table for reference only.

    and in the lockdown i made a fastener database of all my fasteners i have used.

    For this screw ISO 14581 M4 and screw head sub-flush 0.1mm i would design a plate thickness and its hole like this.

    Materials and fasteners are expensive - keep fasteners to a minimum quantity sufficient for intended purpose.

    It's possible to do this as a solution but it is and must be always your decision.

    I like where you have found that 3D file for the screw  - it shows the head / thread transition nicely.

    THE ABOVE METHOD IS QUITE COMMON for securing large area but relatively thin metal sheets needing Csk screw heads. For machined plates, increase it's thickness is usual.

    To make a hole (simple way), i use a section and project the fastener csk section line, then draw other drill lines to make a 1/2 cutter pull face on fastener CL. Make a hole, copy move as required.

     

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