Dagger pin inseparable assembly

[dthom0425]

Hi all - I'm curious as to how some of you might detail the press fit of a dagger pin into a metal plate.

I want to ensure that the flange of the dagger pin fully seats against the flat of the metal plate it's being pressed into. I've seen people put a .000 +.xxx/-.000 dim/tol on the drawing. I've also seen some fancy notes like "press fit dagger pin into part. pin flange shall not stand proud more than .XXX"

Curious as to how some of you may have handled this.

Thanks

 

[drawoh]

dthom0425,

My assumption is that I will order from my vendor, a part, specified by a drawing. The drawing will have a BOM which will call up the base material and the dagger pin, and any other pieces that are required.

A basic drafting principal is that you do not tell the vendor how to do his job. Call up the pin. Specify its location, and specify that it is to be press-fit. If you are making a lot of pieces, you are willing to do destructive testing, and you are anal retentive, you can specify a test in when you use a specified force to try to rip the pin out of its hole.

When I call up dowel pins, I apply a dimension and tolerance to control its height above the part face. When I call up thread inserts, I apply a generic note stating that the inserts are to be installed as per the manufacturer's instructions.

--
JHG

 

[mfgenggear]

@dthom0425
drawoh very much covered it.
but I what can add is if it is important I would ad a note that the pin must bottom out unless a .005 gap is permissible. or what is must be.
FYI depending the procedure of the assembly(freeze and heat if permissible) tiny parts have a very fast thermal change. and when hot and cold parts when assembled it will seize quickly.
before bottoming out, if not done very quickly. Drawohs comments are wise, a dimension to the top the pin is recommended.
the length of the pin - the distance of the hole = final height of the pin. or equivalent,
depending on the configuration of the pin a press can then be utilized to press the pin flush to the bottom.
small holes have less thermal expansion due to the size. and each type of material have different thermal expansion. thermal expansion constant x in/in.
FYI look at the press required, and if hole and pin thermal expansion will not clear for assembly, then a cold press will be required.