Not all rods are created equally

[Aeroliner]

Looking through my parts today I found one of the heavy beam rods in its original box. The forging number is 600-4. Had a pair of these but who knows where the others went.

Alan

[smittythewelder]

Did or do any of you guys get your used Merc rods re-sized? The big end gets elongated, isn't round anymore. But any good auto machinist with a rod-honing machine and the dimension you supply can grind both of the mating surfaces of the big end, then re-size the I.D.. Nearly always this will leave a very small area in a corner at the mating line where the hone didn't quite clean it all up, but you can't keep grinding, and I doubt this makes any difference, especially compared to having a round hole. I would speculate that a used Merc rod that has been trued in this manner is likely to have stretched about as much as it's likely to, and should hold its restored shape fairly well.

[R Austin]

When reconditioning these rods, the bearing surface of 60 rockwell C is only about .025 deep. To much removal will lead to unwanted results. Bearing failure.

[smittythewelder]

Right, and even if you don't go clear through the case-hardening, if it gets too thin it might suffer Brinelling and flake off.