Torque Wrench

[Mike_H]

Are these the wrenches you're looking at?
https://www.harborfreight.com/12-in...fessional-split-beam-torque-wrench-57923.html
https://www.harborfreight.com/38-in...fessional-split-beam-torque-wrench-59108.html

If so, the bolded portion of the quote above isn't a good assumption. See the red circled portion of the manual below. Also, see the yellow circled portion. Although it's infrequent, I do find a need to use a torque wrench in a counterclockwise direction occasionally, so I try to stay away from directional wrenches.
View attachment 578952

Those are the ones. I guess I stand corrected. Will have to make a sticker on the case to remind myself to lower the torque setting when I put them away. 40% off coupon is pretty nice...I picked up the 3/8" 20-100 ft lb and the 1/2" 40-250 ft lb plus a 3/8" and 1/2" breaker bar for less than 200 bucks. Still leaves a small hole in my ranges that I'll need to find something for...I have an older snap on dial for inch-lbs (great for reading bearing preload) but that only goes up to about 150 inch pounds (like 12.5 foot pounds)...so anything below 20 ft-lbs and over 12 isn't covered... but then again, I've tightened so many 1/4" and 5/16" bolts, I have a pretty good feel for how tight they are.

 

[sab]

Split beams and clickers both have advantages. I torqued my oil pan bolts with an inch-pound split beam, but its a huge pain to get my head under the wrench, on the floor, and then I'm too close to see it. Have to jack the Jeep waaay up. A clicker is nice for the places you just can't get your head to see the pointer. A split beam is good for checking how tight the gorilla at the tire shop overtorqued your lug nuts.

OldBuzzard - you're thinking of a beam torque wrench, with the long pointer from the head to the handle. A split beam is an altogether different beast, and they do click at torque so you don't have to read it. Most say they don't need to be reset to zero for storage, but for some reason the Harbor Freight ones do (according to the manual).

 

[OldBuzzard]

OldBuzzard - you're thinking of a beam torque wrench, with the long pointer from the head to the handle. A split beam is an altogether different beast, and they do click at torque so you don't have to read it. Most say they don't need to be reset to zero for storage, but for some reason the Harbor Freight ones do (according to the manual).

Thanks for the correction. I edited my post #19 to correct it.

My ancient Proto 1/2" torque wrench says to reset to zero for storage, so I always do, on all torque wrenches. I wasn't aware that some didn't ask for it.

 

[sab]

Those are the ones. I guess I stand corrected. Will have to make a sticker on the case to remind myself to lower the torque setting when I put them away. 40% off coupon is pretty nice...I picked up the 3/8" 20-100 ft lb and the 1/2" 40-250 ft lb plus a 3/8" and 1/2" breaker bar for less than 200 bucks. Still leaves a small hole in my ranges that I'll need to find something for...I have an older snap on dial for inch-lbs (great for reading bearing preload) but that only goes up to about 150 inch pounds (like 12.5 foot pounds)...so anything below 20 ft-lbs and over 12 isn't covered... but then again, I've tightened so many 1/4" and 5/16" bolts, I have a pretty good feel for how tight they are.

I have no personal experience with split-beam torque wrenches, but it appears that the adjustment mechanism changes the preload on the longer of the two beams inside the handle, and that beam is a leaf spring. In contrast, the adjustment mechanism in a traditional clicker torque wrench changes the preload on a coil spring, which is a torsion spring. Both leaf springs and torsion springs are subject to creep over time because they are steel, which would mean preload should be removed for storage if the preload results in a high enough strain. I don't know why so much of the Internet guidance out there is that you don't have to remove preload on a split-beam wrench. As with all springs, creep strain must be considered in the design.

That said, if the spring in either wrench is properly designed (note: physical constraints can prevent that), creep shouldn't be an issue. It's always been my belief that storing my clickers with preload really won't make much difference because the creep strain limit for steels is usually the last thing that will be an issue when designing a spring. In fact, it's not uncommon for a spring designer to completely overlook it. However, I don't want to test my theory because reliable torque wrenches cost money, and I don't like to part with mine. My OCD-like nature made it easy to develop the habit to remove the preload before it goes back in the drawer every time...

 

[Rickyd]

The last time I needed a 1/2" torque wrench i bought a snapon off ebay that had been recently calibrated. Came with the paperwork. I get a lot of snapon,mac,proto tools on ebay and marketplace for cheap from mechanics on a bender,divorce,etc

 

[sab]

Also, if you ever need to get a torque-wrench repaired or calibrated, these guys do good work:

www.teamtorque.com

However, if it's a cheap torque wrench, it'd be cheaper to buy a new one.

 

[Mike_H]

I wish I still had access to my torque test machine. Back in my automotive engineering days, we had many, many, electric screw guns. They needed to have the transducers checked at least annually, and sometimes more frequently based on the application of the screw they were driving. The machine it self had to be calibrated as well, so I could always check torque wrenches to make sure they were at least in the ball park.

My last one (an old Pittsburgh clicker from harbor freight) got to where it wouldn’t “click” or if it did, it was so faint you could barely hear it. Last time I was putting wheel lugs on, I threw it in the garbage because it wasn’t clicking and i knew I was putting WAY more than 90-100 foot pounds on the studs.

 

[OldBuzzard]

In the aerospace industry, we had to send our torque wrenches to our metrology lab for calibration every couple of months. Once, when they found one which was too far out of spec, and it had been used on a booster which was already on the launch pad at Cape Canaveral, we had to de-stack the payload to recheck / replace bolts. That was VERY expensive in money, time, and blacklisting on future Federal contracts.

 

[GregBelleville]

In the aerospace industry, we had to send our torque wrenches to our metrology lab for calibration every couple of months. Once, when they found one which was too far out of spec, and it had been used on a booster which was already on the launch pad at Cape Canaveral, we had to de-stack the payload to recheck / replace bolts. That was VERY expensive in money, time, and blacklisting on future Federal contracts.

That decision must have been made post Challenger disaster I'm guessing?

 

[Mike_H]

In the aerospace industry, we had to send our torque wrenches to our metrology lab for calibration every couple of months. Once, when they found one which was too far out of spec, and it had been used on a booster which was already on the launch pad at Cape Canaveral, we had to de-stack the payload to recheck / replace bolts. That was VERY expensive in money, time, and blacklisting on future Federal contracts.

We were assembling outside rearview mirrors and door handles. Holding the actuators down was a BIG deal...if the screws fail and the mirror falls off due to vibration, its a recall, yard campaign, federal FMVSS violation, etc. Bad news. Maybe not as bad as a space shuttle disaster, but probably as expensive (considering I was working on the F150 at the time and the impact would have been 100's of 1000's of vehicles). We spent about 10K on each driver to purchase. They monitored pure torque, but would also count number of turns and degrees past "tight." as tightening strategies. Total turns, multiple torque stages, total degrees rotation, etc. All necessary, since driving screws into plastic is more art than science, since the plastic, at a micro level, is always a little bit different. Different amounts of glass filler in the local area of the screw and the orientation of the strands all make the torque MUCH more variable than you would want. Then you add the human factor of mold and assembly machine maintenance, the screw variation, and the mating part variation...it was a LOT to keep my arms around.

 

[sab]

In the aerospace industry, we had to send our torque wrenches to our metrology lab for calibration every couple of months. Once, when they found one which was too far out of spec, and it had been used on a booster which was already on the launch pad at Cape Canaveral, we had to de-stack the payload to recheck / replace bolts. That was VERY expensive in money, time, and blacklisting on future Federal contracts.

We were assembling outside rearview mirrors and door handles. Holding the actuators down was a BIG deal...if the screws fail and the mirror falls off due to vibration, its a recall, yard campaign, federal FMVSS violation, etc. Bad news. Maybe not as bad as a space shuttle disaster, but probably as expensive (considering I was working on the F150 at the time and the impact would have been 100's of 1000's of vehicles). We spent about 10K on each driver to purchase. They monitored pure torque, but would also count number of turns and degrees past "tight." as tightening strategies. Total turns, multiple torque stages, total degrees rotation, etc. All necessary, since driving screws into plastic is more art than science, since the plastic, at a micro level, is always a little bit different. Different amounts of glass filler in the local area of the screw and the orientation of the strands all make the torque MUCH more variable than you would want. Then you add the human factor of mold and assembly machine maintenance, the screw variation, and the mating part variation...it was a LOT to keep my arms around.

Twenty years ago, when I was at Polaris, we had to identify critical fasteners in every assembly. Critical meaning serious injury or death could occur in the event of failure. You can imagine the ambulance chasers lined up to sue a powersports company! On the assembly line, torque drivers connected to a database were used to tighten fasteners to torque. When one of those attorneys would file suit claiming that a fastener was not tightened at the factory, and the vehicle fell apart and caused the crash, the corporate attorneys would provide the database entries during discovery, quashing that strategy. It didn't necessarily kill the lawsuit, but it prevented huge sympathy payouts from the jury...

 

[OldBuzzard]

Twenty years ago, when I was at Polaris, we had to identify critical fasteners in every assembly. Critical meaning serious injury or death could occur in the event of failure. You can imagine the ambulance chasers lined up to sue a powersports company! On the assembly line, torque drivers connected to a database were used to tighten fasteners to torque. When one of those attorneys would file suit claiming that a fastener was not tightened at the factory, and the vehicle fell apart and caused the crash, the corporate attorneys would provide the database entries during discovery, quashing that strategy. It didn't necessarily kill the lawsuit, but it prevented huge sympathy payouts from the jury...

Likewise in aerospace, so you can go back and see why your $billion spacecraft failed to land on Mars. That's when you notice the numbers look like metric instead of imperial.

 

[sab]

Likewise in aerospace, so you can go back and see why your $billion spacecraft failed to land on Mars. That's when you notice the numbers look like metric instead of imperial.

I have a good friend, and former Polaris engineering co-worker who is at Goddard now. He tells of some crazy efforts they go to in the name of QC/QA. They do take wasting our money (taxes) personally, it seems. I said, "but what about the taxes you're spending on the crazy QC/QA?"

 

[sab]

My last one (an old Pittsburgh clicker from harbor freight) got to where it wouldn’t “click” or if it did, it was so faint you could barely hear it. Last time I was putting wheel lugs on, I threw it in the garbage because it wasn’t clicking and i knew I was putting WAY more than 90-100 foot pounds on the studs.

My guess, and it is just that - a guess, is that it wore out due to poor materials. A few years ago, I took two decades-old Craftsman clickers that didn't work, but were favorites of mine, made one good torque wrench from the parts, and sent it to Team Torque for evaluation/calibration. All they had to do was zero out the spring preload - no parts needed replacement!

In the process of messing with those two clickers, I saw how the clicker mechanism works. There's a little steel cube that sits between two flat surfaces, but at an angle so that the cube is resting on the edges (lots of contact pressure there!) The coil spring changes the force pinching the cube between the flat surfaces. When you reach proper torque, the cube cams over-center, and that creates the click. The cube and the flat surfaces need to be very hard to avoid the edges of the cube rounding. My guess with the Pittsburgh brand (Harbor Freight's original cheap brand), is that they didn't use a very hard steel for those components, so over time, the corners rounded over, making the click "disappear."

 

[FarFire70]

I have no personal experience with split-beam torque wrenches, but it appears that the adjustment mechanism changes the preload on the longer of the two beams inside the handle, and that beam is a leaf spring. In contrast, the adjustment mechanism in a traditional clicker torque wrench changes the preload on a coil spring, which is a torsion spring. Both leaf springs and torsion springs are subject to creep over time because they are steel, which would mean preload should be removed for storage if the preload results in a high enough strain. I don't know why so much of the Internet guidance out there is that you don't have to remove preload on a split-beam wrench. As with all springs, creep strain must be considered in the design.

That said, if the spring in either wrench is properly designed (note: physical constraints can prevent that), creep shouldn't be an issue. It's always been my belief that storing my clickers with preload really won't make much difference because the creep strain limit for steels is usually the last thing that will be an issue when designing a spring. In fact, it's not uncommon for a spring designer to completely overlook it. However, I don't want to test my theory because reliable torque wrenches cost money, and I don't like to part with mine. My OCD-like nature made it easy to develop the habit to remove the preload before it goes back in the drawer every time...

I had similar thought that it's pretty easy to just knock it back to a lower torque setting for the split beam. You can feel the increased spring tension on a clicker wrench. You don't feel that with the split beam, until you lock in the lever closed.

But as far as usability - the split beam is way easier. I enjoy popping the lever open, making the quick change, and then slapping the lever forward like I'm landing a mag or driving home a rifle bolt. Just a 'fun' experience vs Do the Twist...

I usually put mine back to the 50 ft/lb that it arrived loaded when new. It can go a little lower but I always worry to bottom out any torque wrench to or at the bottom of it's usable range for fear of over-shooting and ending up with it coming apart or causing any internal issues due to over-relaxation (likely over thinking it - but it's my mindset).

 

[sab]

I usually put mine back to the 50 ft/lb that it arrived loaded when new. It can go a little lower but I always worry to bottom out any torque wrench to or at the bottom of it's usable range for fear of over-shooting and ending up with it coming apart or causing any internal issues due to over-relaxation (likely over thinking it - but it's my mindset).

I have no idea about split-beam wrenches since I don't own one, and, thus, never had one apart. However, with the clickers I've had apart (the two Craftsman and one other one), I can say that it wasn't possible for them to come apart. They have roll pins in place to prevent that. And over-relaxation of a spring isn't "a thing."

 

[steelhd]

Anyone tried the Harbor Freight Icon? I just got an email from them 40% off all ICON wrenches tomorrow.

If you Google Icon vs Snap On torque wrench there have been tests showing that the Icon is very accurate. Whether the are durable or will hold accuracy over time may be another thing.

 

[steelhd]

From Project Farm ...Best Torque Wrench? $450 Snap On vs Craftsman, ICON, Kobalt, DeWalt, SK Tools, Proto, Wera​