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Something which I've been trying to find an answer to for quite some time, but a Google search reveals nothing obvious and no-one seems to know, despite drill MFRs commonly quoting them in specs. So, does anyone know the difference between 'hard torque' and 'soft torque'?
Hard is for "real" men and soft is for pansies!
Aww I though I had an answer then! :(
Just for instance, look at the 'Technical Data' section of this page: http://www.bosch-professional.com/gb...gsr-14-4-2-li/
I'm going to hazard a guess that the torque numbers are for the different speeds that you can select...
I don't know what soft or hard torque represent, actually curious myself.
It could be the max and min torque settings you can choose for screw driving, for example a low or soft torque is useful to prevent over driving screws in to softer materials. Many of the cordless drills I've used have a feature which disengages the drive when there is a certain level of resistance depending on the setting it's on, i.e. the drill stops spinning once the screw is in to a level of 'tightness' of my choosing.
That would make sense for drill with multi-speed gearboxes, the lower speeds having more torque, but I think I've seen it quoted on single-speed models too.Quote:
Originally Posted by Blastuk
Yeah maybe 'soft torque' is given for the number 1 setting, and 'hard torque' is the highest number or possibly the drill setting. If I can dig out a torque wrench I might be able to give that a go, see if the clutch slips with the soft torque on the first torque setting.Quote:
Originally Posted by DDY
Either way, I think they could have used much better terminology; if this is the case then a very low soft torque may be desirable but people unsure of the term may think this is the max torque and go for a drill with a higher rating...
Got me curious too.
I found this
http://www.diynot.com/forums/viewtopic.php?t=142158
which wasn't much help itself, but got me thinking...
power is the product of torque and speed, so for a given power input to the drill, a lower gearbox speed will produce higher torque. But speed is also controlled electronically, by varying the power inputto the motor, so as the motor speed drops, the torque will drop too. The way the motor is controlled has some significance though, because although torque is related to power, , and power is related to voltage and current, it gets complicated!
I won't go into electric motor theory, but the electronic controllers on drills maintain higher levels of torque at lower speeds than a simple variable resistance type of controller, so I wonder if sopft torque is that produced at lower, electronically controlled, speed settings.
On Consumer drills like the Bosch it's giving a max torque for hard and soft, presumably this is the maximum torque the drill can exert on the screw head when driving. The Hard and soft are probably just the difference between driving a 4in screw into 6in hardwood and driving a 1.5in screw into softwood for example. With the longer/thicker screw there's more resistance so it will be able to exert less torque ? Everything is a bit subjective at lower price/spec levels.
In higher spec Pro drills they tend to just have a max torque rating, then variable torque settings can be applied in the same manner as with torque wrenches.
That Bosch I linked is from their professional range (mostly agreed to be better than DeWalt, for instance), some of their consumer range actually quote a single number. The size of the screw would have no relation to the amount of torque the drill is capable of producing, a bigger screw couldn't somehow make the drill produce less torque than a smaller one. Don't confuse torque with speed.Quote:
Originally Posted by Barakka
I know but at that price break and spec it's not what a lot would call pro, a pro screwdriver maybe. DeWalt is Black & Decker in a yellow and black case, nothing more. For true pro see something more like this, giving 100Nm as opposed to 38Nm but still only 15v, but 3 times the price.Quote:
Originally Posted by watercooled
My point was more about the associated thickness of the screw AND the material it was being driven into affecting toque delivery by the strain placed on the motor.Quote:
Originally Posted by watercooled
Anyway I was along the right lines, it's about the delivery of the torque in relation to what is being driven into what, but I was still wrong...
;)Quote:
So-called "soft application" is defined by a gradual increase in the torque up to the maximum load value (e.g. driving crosshead screws into soft wood).
During "hard application", the bit reaches the maximum strain in torque only at the end of the screwdriving process (e.g. driving threaded screws in metal railing).
I know plenty of people who work in the building trade and rely on Bosch tools (as well as others) which just last and last. They also said basically the same thing as you about DeWalt, yet it seems to be the brand a lot of people are thinking of when they say 'professional' tools. Festool may be a notch up but for the most part an unnecessary jump in price, according to their experience anyway. But the likes of Makita, Hitachi, Bosh, Milwaukee, etc come highly praised.Quote:
Originally Posted by Barakka
Edit: Oh and to be fair, that Festool is an impact driver so not at all comparable to a standard drill/driver in terms of torque. For example: http://www.bosch-professional.com/gb...gdr-14-4-v-li/
But that's besides the point, as much as I could talk about tools all day. :P
Interesting, where did you find that quote? I was thinking along those lines i.e. sustained vs surge torque, but couldn't think why they would be named hard and soft - that quote makes sense of it.Quote:
So-called "soft application" is defined by a gradual increase in the torque up to the maximum load value (e.g. driving crosshead screws into soft wood).
During "hard application", the bit reaches the maximum strain in torque only at the end of the screwdriving process (e.g. driving threaded screws in metal railing).
Sorry, I was perhaps being a bit obtuse in the response, it just annoys me when I see brands labelled as 'professional' when they're far from it, the Bosch you linked is a decent tool no doubt, but as said, people see DeWalt and assume professional quality when it's far from it.Quote:
Originally Posted by watercooled
I do work for a tool company who've spent 30 years in the building trade and over 15 selling and repairing all brands of tools. Bizarrely the quality of drills tends to come down to where they are made, Makita for example had a drill model of theirs which was made in one place and was fine, then they moved production to a different factory (I think it was to a different region in China) and the failure rate went through the roof. The guys in the shop can tell how good they are instantly from the serial no. (OCD ;)) and could point at a wall full and go "Good", "Good", "Rubbish", "Good"... The main problem with the lower pro brands like Bosch, Makita, etc is that they use factories all over the world, and you never know how good a tool will be until you have some sales (or more accurately returns) history. They're all designed well but the manufacturing standards can vary wildly.
That's part of the reason Festool is so good, they're made in Germany, no compromise, they're also NASA's choice of tool, not a bad recommendation - well until they stopped flinging people at the sky.
Found that on the Weber website talking about hardened bits... HereQuote:
Originally Posted by watercooled
Just a misunderstanding, the perks of text communtcation! ;)Quote:
Originally Posted by Barakka
I agree, something else which really annoys me is some, shall we say 'less good' brands, using German-sounding brand names for their tools to imply quality.Quote:
Originally Posted by Barakka
Hmm Hitachi seem to quote lock torque (presumably on the clutch-locked drill position) and slip or clutch torque. An example model delivers 52Nm 'lock' torque but between 2-10Nm torque settings.
I think I might have to do some testing (and hope the specs are accurate) to see what they actually mean once and for all. After more thinking, would the difference be so great between sustained and surge torque, with the gear ratio on drills being so high and using a type of motor that delivers high starting torque?