Spirol International posted How to properly pin a shaft and hub assembly Spirol International Danielson, CT:

How to properly pin a shaft and hub assembly

The hole in a shaft should not exceed 1/3 of the shaft diameter. For mild steel and non-ferrous shafts, standard duty pins are recommended. The extra strength of a heavy-duty pin is only beneficial if the hole is less than 1/4 the diameter of the shaft or if the shaft is hardened (Figure One).
It is recommended that the hub be designed with a minimum wall thickness of 1.5 times the diameter of the pin. Otherwise, the strength of the hub will not match the shear strength of the pin (Figure One). As the wall thickness of the hub increases, so does the area of material around the pin.
The diameter of the holes through both the shaft and hub should be precision matched to eliminate any movement of the pin within the holes. It is recommended that the difference between the hole diameters in the hub and shaft not exceed 0.05mm (0.002 inches) to prevent movement of the parts relative to each other. Otherwise, the pin will be subject to dynamic loading such that a very small change in velocity could equate to a significant change in force impacting the assembly.
The hole should be centered in both the shaft and hub to prevent stress concentration and ensure there is enough material around the pin to withstand the applied forces.
If the holes cannot be precision matched, dividing the tolerance between the shaft and hub is recommended. The larger half of the tolerance should be applied to the component with the longest engagement length, and the smaller half should be applied to the other component.
Countersinks on the holes are not recommended. In addition, the outer diameter of the shaft (OD) and the inner diameter of the collar (ID) should be designed such that the distance between the shear planes (OD-ID) does not exceed 0.13mm (0.005 inches). In both cases, an unsupported length of pin in an area where torque may be applied is created. This could cause a bending moment, which shortens the lifespan of the pin (Figure 2).
Installing a cylindrical pin into a hole on the surface of a cylindrical object leads to two point contact between the pin and the hole. This concentrates the compression force on only two points of the circumference. To increase the contact surface between the periphery of the hole and pin, and to ease installation, a flat should be placed on the exterior surface of the hole (Figure 3).
It is important to start with the…

How to properly pin a shaft and hub assembly
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