Most people might be familiar with a basic socket set. Yet, drive size might be less obvious.
The following is by my understanding.
I recall buying a socket one time to remove the anode of a hot water heater. It was, I think, one-and-one-sixteenth. I bought it from a discount bin, and it came on a straight bar. I was in a hurry, so didn’t think much of it.
Later, I had to buy a 15/16″ socket to undo an oil filter casing. The clerk asked me what drive I was using. I didn’t know. The socket was 1/2″ drive. He assumed, correctly, that I would need an adapter from 3/8″ drive to 1/2″.
Back then, I just had a standard socket set from Mastercraft. It had both 1/4″ and 3/8″ drives, and its largest socket was 3/4″. It hadn’t occurred to me that bigger drives – for instance, 1/2″, were called for sometimes. However, when I got home from buying the 15/16″ socket, I inspected the one-and-one-sixteenth socket, on its bar, that I’d bought years ago to remove the water heater anode. Indeed, that socket, too, was 1/2″ drive.
When I thought about it, the reasoning was obvious why 1/2″ drive might be called for: a bigger fastener might well mean it’s under more strain, so needs to be tighter. In turn, a larger-diameter drive would be stronger, so less likely to break when removing such a fastener.
It turns out that, for 3/8″ drive, the torque range tops out around 75 ft*lbs, then for 1/2″, around 250 ft*lbs.
It’s hard to imagine me, personally, applying more than 250 ft*lbs of torque, but apparently that’s when 3/4″ drive becomes relevant.
Source:
eTork. (Sept 4, 2024). “Torque Wrench Sizes Explained.” https://etork.com/torque-wrench-sizes/