Pressed joint of plated part on knurled surface

[Trukker]

I have a 1/8" thick Zinc plated steel disc with a 1 1/2" hole in the middle. The hole is chamfered 2/3 of the way & has straight knurling (0.012" deep) formed on the chamfer.I need to insert a steel tube through the hole and press it down on the knurled surface to make secure joint between the tube and the disc with ability to withstand some torque.

I have not Zinc plated the tube as I am not sure if that will compromise the joint security. But it seems I need to provide surface protection on the tube. I would appreciate your inputs on this.

Thanks

 

[TVP]

Zinc plating is ductile, so it is capable of deforming during assembly operations such as this. However, there are always limits, and it is possible that the plating could be damaged to the point where corrosion protection is limited. I would not be concerned about the joint security. Is there a reason why the two pieces cannot be plated after assembly? Why not make the part just one piece instead of two that require assembly?

 

[Trukker]

Thanks TVP,

The tube was a simplification to focus on the actual problem and not bring in unnecessary details. Actually the "tube" is the pawl carrier of a one-way clutch and the forming operation integrates a total of 10 parts into a one-way clutch. So I will have to plate the pawl-carrier separately. The concern arose because the clutch torque has to be carried by the joint.

Your confidence in the joint security was very helpful. I am thinking more analytically now. The plating thickness (10 microns) is only 3.3% of the knurl depth so the parent material should get formed OK.