1/2 inch vs 13 mm.

[Jstpssng]

I've always used these interchangeably, although the metric is slightly bigger.
(+- 2%) Yet 1/2" is too small for the nuts on the bar for my Echo saws. Yesterday I was tightening the tailgate latch on my pickup and found that 1/2 was too small for that, also. Apparently my 1/2 inch sockets only identify as metric.

 

[orezok]

Maybe your nuts identify as Chinese

 

[LD1]

Its a stretch to use those two interchangeably. On something that isnt super tight or rusted....sometimes I grab a 13mm if I see that wrench/socket before I see the half.

Half is a TIGHT fit on some 13mm stuff and a good choice if your worried about rounding. But those two really "shouldnt" be interchanged. But several others are MUCH closer....commonly:

8mm - 5/16..........0.315" - 0.3125"..........+/- 1%
11mm - 7/16........0.433" - 0.4375"...........+/- 1%
14mm - 9/16 ........0.551 - 0.5625"..........+/-2% (this one is almost as bad as 1/2 vs 13 mm)
16mm - 5/8" .........0.630 - 0.625.......+/- 0.8%
19mm - 3/4" ...........0.748" - 0.750....+/- 0.3% (dead ringer given mfg tolerances. Im convinced they are the SAME mold just labeled differently)
22mm - 7/8............0.866 - 0.875.... +/- 1%
24mm - 15/16......0.945 - 0.9375....+/- 1%

The metric "bastards" with nothing close are 10,12,15,18.....and those are VERY common if you wrench on cars and small equip

 

[tacticalturnip]

Maybe your nuts identify as Chinese

I laughed audibly.

 

[CliffordK]

I've used them interchangeably quite a bit. I do have one car that has a square female 13mm oil drain plug. So, the 1/2" socket drive is the choice for it.

My latest purchase is a Land Rover, and I'm now discovering that I should purchase whole new Whitworth wrench and socket set.

 

[oldnslo]

I've always used these interchangeably, although the metric is slightly bigger.
(+- 2%) Yet 1/2" is too small for the nuts on the bar for my Echo saws. Yesterday I was tightening the tailgate latch on my pickup and found that 1/2 was too small for that, also. Apparently my 1/2 inch sockets only identify as metric.

Bolts on tail gate could be metric also.

 

[5030]

I believe it all depends on how tight of tolerance the sockets are made to more than anything else or how worn the socket is as well. Sockets do wear out, especially on an impact wrench.

 

[DarkBlack]

Anything 1/2” or 13mm I bring both wrenches or sockets and use whichever one fits tighter, to avoid possible damage to the nut or bolt.
I do the same for 3/4” and 19mm.
I’ve done this for years. It’s second nature now

 

[Jstpssng]

Bolts on tail gate could be metric also.

They are,as I found out yesterday.
When I got my first socket set for Christmas many years decades ago they didn't include a 13mm. Or maybe it was 1/2 inch.

 

[ponytug]

I've used them interchangeably quite a bit. I do have one car that has a square female 13mm oil drain plug. So, the 1/2" socket drive is the choice for it.

My latest purchase is a Land Rover, and I'm now discovering that I should purchase whole new Whitworth wrench and socket set.

Welcome to the true joys of British engineering. And, yes, I would purchase the sets. Too much heartache and skinned knuckles trying to find something "close".

All the best,

Peter