To late to harden it, if it comes as T6 the job is done. T6 is by definition solution heat treated & artificially age hardened which means it was heated in an oven or salt bath to its upper critical temperature, from memory about 525Deg C, then quenched in room temperature water. The hardening is followed by reheating in an oven to 120-170C then air cooling.I am making a sprocket carrier for our twin racer I am making it out of 6082T6 this seems suitable and available in the large size i need commensurate with cost
I am thinking perhaps I should harden it after machining, as I have had some wear in bolt holes on previous items (OK they may have come loose )
comments welcome
If you are concerned about wear in bolt holes then I would suggest fitting interference fit shouldered steel sleeves to spread the load. Use the 10 bolt hole hub, no question. I know it's a racer & you want to add lightness, try the 5 bolt hub, no steel sleeves first, when it cracks or comes loose on the bolts, you have next season's solution.