Recommendations for a cheap torque wrench
- Thread starter MikeyH
- Start date
Devon
Thank you markplant, I will have a look, it'll make a nice Christmas pressy for me
I use a Halfords Advanced too.
I suspect you get what you pay for with torque wrenches.
@enuff_zed is probably the expert in this space.
I suspect you get what you pay for with torque wrenches.
@enuff_zed is probably the expert in this space.
Attleborough, Norfolk
No expert tbh, but I will say whichever one you get will only ever be approximate. We used to have our torque wrenches calibrated every three months, but then had a proper metering device bolted to a bench that we used to check the torque on. It was calibrated monthly. The torque wrenches themselves were never quite accurate so we would use the meter to set them.
To maintain even a moderate accuracy the torque wrench should be wound right back to take tension off the spring after every use.
I have no experience with these new electronic ones other than hearsay that they are very difficult to read compared to the solid clunk of the older types.
Even then the torque can be influenced by how rapidly you operate the wrench, whether the bolt is dry or lubricated and whether you stop immediately when the correct torque is reached.
In short, with a modicum of common sense and engineering nous it is sometimes just as easy to judge it by hand.
To maintain even a moderate accuracy the torque wrench should be wound right back to take tension off the spring after every use.
I have no experience with these new electronic ones other than hearsay that they are very difficult to read compared to the solid clunk of the older types.
Even then the torque can be influenced by how rapidly you operate the wrench, whether the bolt is dry or lubricated and whether you stop immediately when the correct torque is reached.
In short, with a modicum of common sense and engineering nous it is sometimes just as easy to judge it by hand.
I agree with Martin. Unless you have them calibrated every five minutes, they are only an approximation, so I would get the cheapest you can find.
I have noticed that the 'cheapest' end of the market; ie screwfix, tool station, machine mart, draper, silverline, etc are all exactly the same tools just badged differently.
Presumably @MikeyH you are looking for a 1/2" drive from around 50nm up?
I have noticed that the 'cheapest' end of the market; ie screwfix, tool station, machine mart, draper, silverline, etc are all exactly the same tools just badged differently.
Presumably @MikeyH you are looking for a 1/2" drive from around 50nm up?
I think that a torque wrench, no matter how 'out of whack' is useful as you do get the 'click' which helps not to overtighten stuff too much, especially for clueless types like me.
I've had a Kamasa 1/2" drive one for years that seems fine, but then I only tend to use it for wheel bolts! You can get one of those for less than £50 on Ebay, and I find the "click" very satisfying.
If I was using one for lower torque applications I'd probably pay more for a good 3/8" drive one.
If I was using one for lower torque applications I'd probably pay more for a good 3/8" drive one.
Probably of no help here but I have a Snap-On 1/2" torque wrench which I got new in mid 90's from one of their mobile reps when I was working in the rail transport industry. I've had it recalibrated a few times, apparently not really much off kilter when done. I remember the rep telling me the best thing to do if you dont use them often or don't have regular recalibration is to wind them back to release tension.
What size drive?1/4, 3/8, 1/2"
3/8" drive covers most applications.
What torque? Under 50Nm or over 100?
A smaller one is more accurate for lower torque settings. A large high torque wrench is practically useless at low torque settings.
I have a more accurate 3/8 drive upto 50Nm (£100, calibrated Norbar) and a cheap 1/2" Draper for wheel bolts.
They are only accurate if you zpend over £100 and have them calibrated annually.
ALWAYS UNSCREW BACK TO ZERO WHEN YOU HAVE FINISHED USING IT OR IT WILL SOON BE VERY INACCURATE (I learnt this when my wheels almost fell off!)
Good luck
3/8" drive covers most applications.
What torque? Under 50Nm or over 100?
A smaller one is more accurate for lower torque settings. A large high torque wrench is practically useless at low torque settings.
I have a more accurate 3/8 drive upto 50Nm (£100, calibrated Norbar) and a cheap 1/2" Draper for wheel bolts.
They are only accurate if you zpend over £100 and have them calibrated annually.
ALWAYS UNSCREW BACK TO ZERO WHEN YOU HAVE FINISHED USING IT OR IT WILL SOON BE VERY INACCURATE (I learnt this when my wheels almost fell off!)
Good luck
I bought a 1/2" torque wrench (Halfords standard job in a grey blow molded case) in about 1997 when I started tinkering with cars. It mostly got used as a breaker bar since I didn't know such things existed at the time. Once, in a fit of excitement, I stuck it in the vice, hung a bucket of rocks on the end and waved mathematics at it to find that it was pretty accurate. Many years later I bought a 3/8" job too.
In the thick end of 30 years I've rarely used them, the chief use for the 1/2" drive possibly to calibrate my arm so I got an idea of how much force I should throw at things. I've done suspension arms, wheel nuts, brakes galore, inlet manifolds, top end engine stuff (rockers, valve covers etc) - almost all by feel and never killed myself even slightly, had anything come adrift and (almost never) broken anything. I've also been able to undo them again as I've not gorilla'd them on either. The only times I've really used either in anger have been:
In the thick end of 30 years I've rarely used them, the chief use for the 1/2" drive possibly to calibrate my arm so I got an idea of how much force I should throw at things. I've done suspension arms, wheel nuts, brakes galore, inlet manifolds, top end engine stuff (rockers, valve covers etc) - almost all by feel and never killed myself even slightly, had anything come adrift and (almost never) broken anything. I've also been able to undo them again as I've not gorilla'd them on either. The only times I've really used either in anger have been:
- Tighten to X Nm + 90 degree joints
- Glow plugs (both undoing and doing up - they're something like 8 or 10 Nm and they will snap if abused.)
- Rebuilding a Smart car engine. A lot of that comes under the first bullet point really but there were various hollow banjo bolts that absolutely would not take even the slightest over-tightening without sheering off - though that rather makes me think they were badly spec'd. Oil sprayers I was glad to do with the 3/8" one for obvious reasons.
- When it goes click, the fastener isn't correctly torqued. You have merely reached the tightening torque and it needs to be held until the fastener has stopped moving. Since people hear a click and immediately release, it ain't properly tightened.
- If you are wont to slather copper grease on everything (ghod save me from the lunatics that put it on wheel bolts), all bets are off. This affects the whole process and the "correct" torque is now meaningless.
My father-in-law gave me a torque wrench that he used in the 80s and hasn't been calibrated for years. I bought a cheapish Draper one from Amazon, and it clicks at EXACTLY the same settings, leading me to believe that they are both pretty accurate.
Even if it's not perfect, it's surely better than just TAF?
Even if it's not perfect, it's surely better than just TAF?
Yes I am
Yes I’ve been looking at that one and it seems a good price, it won’t get much use so a bit daft spending a fortune on one. The only time I ever used one back in the day was for tightening cylinder head nuts, everything else was by feel.
Good advice, thank you.
Please explain how the fastener will keep turning after the click? If you apply any turning moment at all then you will be increasing the tightness. The click occurs when the wrench reaches the correct torque. You seem to imply that somehow there is energy stored inside the wrench that keeps turning the fastener without further input from the user?
During my apprenticeship we had detailed lessons on using special tools, including all the various types of torque wrench. Was never told anything like that.
It's something I heard along the way which made sense so it stuck with me. The fastener is only properly tight when it stops moving with the correct torque applied; the torque wrench tells you that you're applying the correct torque, not that the fastener has finished overcoming whatever friction/stiction/other[1] there is that allows it to keep creeping round. You're not increasing the force but maintaining it. I suppose a good example would be some form of deformable sealing ring (maybe a copper washer would be a good example.) It gets squeezed at whatever force is applied by, say, 50Nm but it takes a finite time for it to finish its non-elastic deformation and crush properly. Apply the 50Nm and immediately take it away again and it's not tightened down properly.
That's how I understand it anyway. It always amuses me to see tyre places wave torque wrenches at wheels going as fast as they can. Say the bolt is 90% tight they don't give it anywhere near enough time to overcome stiction and start moving before they're off to the next.
[1] I am not a tribologist
That's how I understand it anyway. It always amuses me to see tyre places wave torque wrenches at wheels going as fast as they can. Say the bolt is 90% tight they don't give it anywhere near enough time to overcome stiction and start moving before they're off to the next.
[1] I am not a tribologist
I think there may be a slight misunderstanding there?
Once the torque wrench has clicked, you can carry on turning it as much as you like but every tiny movement will increase the torque applied. The wrench, once clicked, just becomes a bar.
What I was taught was that you should go slow and steady until it clicks. This is then the correct torque. I agree with you that whizzing the thing around as fast as you can will lead to the wrench clicking too early, as it effectively gets a sudden loading on it.
For the crushable washer scenario, I guess this is why my teaching included going back to every fastener a second time and checking it again. Something I still do, and yes, on occasion I get another slight tweak before it clicks.