3/8" vs. 1/2" torque wrenches

[wowturtles]

what is more commonly used? and which one is best for what?

asking because i want/need to get both for school but can only afford to get one right now. the class will be an engines class then suspension class this semester. the school will probably have a community tool for everyone to share but i'd rather just have my own. lol

so whats up guys?

oh yeah, fixed or flex head?

 

[Skin]

if its going to be used in school just buy a cheapo from HF or Sears. One way or another its going to get dropped, banged, or borrowed and probably used as a breaker bar either in your hands or someone elses.

As far as your actual question 3/8" stops at around 100lb/ft which covers most things. Up to 250 is really only needed for the larger chassis fasteners/axle nuts. The only downside to 3/8" is having sockets in that drive larger than 19mm for some things. 21mm, for example, is a common lug size but 21mm deep sockets in 3/8" drive arent overly common.

 

[sickboy motors inc.]

Buy big and use a stepdown

 

[Snapped-off]

Fixed or flex-head seems to be preference. Obviously flex could be useful in some situations.

My dad hates flex-head torque wrenches with a passion, but I don't find it much of a bother.

 

[lasthope05]

The 3/8" size has a smaller torque window with the clicker types and should only be used around 20-60lb ft depending upon brand and their torque scale. The lower and upper ends are not as accurate as spring pressure is either too loose or too tight. Personally I like to stay play it safe and stay in the center 70% of the torque wrenches scale.

The cheap HF ones will do just fine for now and many members on here attest to their accuracy. $20, with a coupon, for both 3/8" and 1/2". Then later on when you find yourself using it more often pick up a better one.

 

[pipsters]

A lot of head bolts are angle torqued. For that an electronic one is best. You can go old school with an angle gauge but it is cumbersome. Eastwood offers a $60 torque adapter that also does angle. Might be a cheap option. They are pretty accurate just look hackish.

Also take a look at Gearwrench
http://www.tooltopia.com/kd-tools-85073.aspx

Torque wrenches are made to be accurate from 20% to 100% of scale within their tolerance. In the electronic case you're talking 2%. Hardly anything. Consistency is much more important. In the end a 3/8 and 1/2 will be needed.

 

[plinker]

You can do alot with a 3/8 drive 5-75 ft lbs and a 1/2 drive 50-250 ft lbs. I prefer fixed head, but my one 3/8 is a flex head. It get's in the way more then it's useful, IMO.

The Gearwrench one's with the 60 tooth head are nice better swing arc the other's with 36 tooh by far. Tooltopia is a good place to buy from as well. I have gotten a couple of torque wrenches off ebay. If you do, pay attention to the description and make sure it's what you are looking for.

 

[t100]

don't forget 1/4", many engine works involve inch-lb specs, specially head jobs.

I wouldn't worry about too much using 1/2" on the suspension, many times that's more forgiving on the bigger bolts.

 

[Gary S]

Match it to what you are working on. If you are working on Hondas, get the small one. If you are working on full size pickup trucks, get the large one.

 

[jetmech09]

A lot of engine components you will find to be in-lbs. You are going to need a bunch no matter what.

 

[Skin]

A lot of engine components you will find to be in-lbs.

internal, the common stuff that you'll most likely really be working on (cam, head, pulley) is lb/ft

 

[SMKS]

Buy big and use a stepdown

This isn't a great strategy, IMO, because of the useful torque range of a large wrench. More info below.

Torque wrenches are made to be accurate from 20% to 100% of scale within their tolerance.

This is an important thing to remember. A 250 ft-lb wrench that isn't even usable below 50 ft-lbs wouldn't be useful for a lot of auto repairs. For big stuff like head bolts, yes, but it's too big for many jobs. My 1/2" drive torque wrench is rarely used, only for suspension and wheels mostly.

I use my 3/8" drive and 1/4" drive torque wrenches far more.

I bought this CDI recently to replace an older Craftsman. It's a good torque wrench for the money ($50), USA made and I've been happy with mine. It's also a range that is useful for me.
http://harryepstein.com/pics/torquewrenchconsolidated.jpg

 

[crewchief888]

i have 4
1/2"dr flex head split beam 50-250 ft/lb SO
3/8" dr flex head split beam 20-100 ft/lb SO
3/8" dr flex head micrometer 5-75 ft/lb SO
3/8" dr beam type 0-?? in/lb CM

i havent used the CM beam wrench since '80
the rest of them have covered everything i've needed, unless i had to use 3/4" dr.

 

[DrkMtnDew]

for school i would go with the 1/2'' model. 40-250 ft.-lbs. most of the stuff i did in school was within this range. usually if you need something smaller the school will have a loaner. after you get out and working on your own then you can look at getting a small wrench.

 

[6-Speed]

I have a CDI 3/8" and PI 1/2". Both are flex-head; they offer better flexibility in cramped quarters than the fixed head type.

 

[osborn.ozzy]

I love my new snap on (CDI) split beam

 

[SMKS]

I love my new snap on (CDI) split beam

The split beams are made for Snap-On by PI.

http://www.torqwrench.com/

The PI split beams are very nice. I don't own one, but if I was in the market for a new torque wrench they'd be one of my top choices.

 

[osborn.ozzy]

The split beams are made for Snap-On by PI.

http://www.torqwrench.com/

The PI split beams are very nice. I don't own one, but if I was in the market for a new torque wrench they'd be one of my top choices.

I think the only difference between them is the ratchet head.

 

[richfinn]

When you get out of trade school and into the workshop, you will find yourself torquing wheel nuts/suspension bolts far more than you will small engine fasteners for at least the first 2 years.

I would go for a 1/2 drive for a junior tech and use your tool discount on the most expensive wrench.

 

[Provincial]

For years I only had a ft/lb torque wrench. I learned math. For instance, 30 ft/lbs = 360 in/lbs.

 

[DFW-LSX]

Buy big and use a stepdown

Doesn't using extensions, step downs, etc skew the accuracy a little?


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[SMKS]

Doesn't using extensions, step downs, etc skew the accuracy a little?


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Don't ask that question!

There are epic threads about this topic that you should search for if you want to learn more.

If memory serves, the answer is no. But, I don't feel like searching for the threads. Here's what I remember from them - While the extensions or adapters may twist slightly, they don't actually affect the final output torque applied to the bolt or nut.

 

[Chadwilliam1]

I have both from kobalt. for the money they work well and come with a lifetime warranty.

 

[antinym]

I would say get a 3/8 beam style. It'll do 0-100lbs, and that's going to be 95% of the fasteners you'll encounter.

 

[SMKS]

I would say get a 3/8 beam style. It'll do 0-100lbs, and that's going to be 95% of the fasteners you'll encounter.

It will probably actually do 20-100 ft lbs. At least that will be the range where it's considered within the stated accuracy.

 

[DFW-LSX]

Don't ask that question!

There are epic threads about this topic that you should search for if you want to learn more.

If memory serves, the answer is no. But, I don't feel like searching for the threads. Here's what I remember from them - While the extensions or adapters may twist slightly, they don't actually affect the final output torque applied to the bolt or nut.

O ok Ill have to dig them up. Just in case anyone wonders, that was a legitimate question not a smart *** comment.


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