Most Common Flare Nut Sizes?

[CobraRed]

I saw some ratcheting flare nut wrenches at SEMA that looked decent, but one size per wrench. Which got me thinking, what size on cars do you guys run into the most? Mostly Metric? SAE?

I've seen some threads mention this, but not much consensus.

I see often:

3/8, 7/16, 1/2, 5/8" 10's 12's and 17's

 

[Milton Shaw]

Most of the time you need a flare nut wrench you need it to break the fitting loose because it's so tight, once loose I switch to open end to get it the rest of the way. Not much use for the ratcheting wrenches as most of the time they are not very strong and round the nut off. The best wrenches I had for flare nuts were not the strongest and would break. The Craftsman wrenches never broke but were so bad a fit they rounded most of the tighter nuts off. Snap-on were somewhere between those two as far as fit.

 

[Strouty]

As a someone who lives in the rusty part of the country, I own the snap on flare wrenches with the flare on one end and the open end on the other and they are excellent. The craftsman set are absolute garbage if any sort of deicer is used on your roads.

As for common sizes it depends on how old your vehicles are, I use mine for hydraulic fittings as well. Newer cars will not have SAE older cars are generally all SAE. So what are you working on?

 

[Squddle]

I have both metric and sae. Depends on the vehicle. You need it to fit really snug so you can break loose the fitting.

 

[sberry]

I am going to agree with the assessment of the Cman flare nut wrench. Its really only bested in the worst tool category by the ratchet. I have a snap or 2 and they are fine and have a set of Proto. I am not sure on how they rank with Snaps which has a quite a bit of testimony that sounds legit.
If we really are dealing with rusty brake fittings I really skip over all of it and go to a 6 or even 10R vise grip on 3/8 and get over it or cut line off and use a socket.
A good tubing wrench is good to use on a salvageable serviceable nut. Shate that is already gone its not worth messing with although I am talented enough with tools can do some work with the grips without actually ruining a fitting.

 

[sberry]

I have a collection in the middle rawer, still have to make one on occasion.

 

[wafrederick]

18mm for most power steering hoses in the GM,Chrysler and Ford products.Same with 12mm and 14mm for brake line fittings,sometimes 13mm.Have encountered 11mm on a BMW once so far for brake line fittings

 

[jrobb316]

All metric sizes are popular for modern day vehicles. I don't understand the hate of the CMan flare nut wrenches, I never had a problem with them and i've used them a lot. I also have a SK set that is top notch.

 

[djb2]

Older BMWs used pseudo-metric sizes such as 11mm (7/16") and 19mm (3/4") for brake and A/C lines. The threads were metric, but the wrench flats were really SAE sizes.

 

[WhiskeyRanger]

All metric sizes are popular for modern day vehicles. I don't understand the hate of the CMan flare nut wrenches, I never had a problem with them and i've used them a lot. I also have a SK set that is top notch.

I've never had a problem with the craftsman wrenches either. I only have the standard set, since I mostly used them working on the beaters we had as kids. Working on 1970's and early 80's cars that spent 20 Michigan winters getting assaulted with salt, no complaints. Now I just use them on my Harleys, but they haven't seen much salt.

 

[TNToy]

I don't understand the hate of the CMan flare nut wrenches, I never had a problem with them and i've used them a lot.

I'm not sure what you've been using them on, but a tool truck flare wrench has, on many occasions at work, removed a power steering or brake line which the Craftsman's began to round off after the jaws on the flare-nut end started to spread.

Craftsmans works most of the time. When they don't, something made with better steel will sometimes save the day.

 

[CobraRed]

These are the two images I had in my phone of them. I mainly work on 1990+ cars. I hate rounding flare nuts and haven't invested in a set yet - these seemed to have solid clicks and used a pawl for the ratchet instead of those funky swinging arms versions.