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torque wrench issues
wrote in message ... On Sun, 30 Apr 2017 21:30:36 +0100, "Ian Field" wrote: "AMuzi" wrote in message news On 4/30/2017 12:01 PM, Ian Field wrote: wrote in message ... On Sat, 29 Apr 2017 19:53:16 +0100, "Ian Field" wrote: wrote in message ... On Tue, 25 Apr 2017 20:16:22 +0100, "Benderthe.evilrobot" wrote: "John B Slocomb" wrote in message ... On Mon, 24 Apr 2017 22:17:14 -0400, wrote: On Tue, 25 Apr 2017 07:42:21 +0700, John B Slocomb wrote: On Mon, 24 Apr 2017 19:51:41 +0100, "Benderthe.evilrobot" wrote: wrote in message ... On Sun, 23 Apr 2017 22:06:05 +0100, "Benderthe.evilrobot" wrote: "Emanuel Berg" wrote in message ... I finally got the 1/2" torque wrench, 28-210 Nm, not even made in China, but in Taiwan! Eh... I guess it depends who you ask if that is China or not It has a locking screw, a torque setting handle, a scale (Nm as well as "FT-LB", some English unit I take it?) - it also as a locking lever on top just like an ordinary ratchet, so it can go both ways, clockwise and anti-clockwise. The torques only work in the clockwise direction. So if the locking (ratchet) lever is set the other way, it is just a ratchet, right? Well, in the manual it says: Note: Never use the torque wrench to undo nuts, bolts or other fasteners as this will damage the ratchet mechanism and the calibrated settings. So how does that add up? Is it only OK to use the anti-clockwise pull to insert things, which would require a left thread? (And it would be just a long shaft, with the torque not in effect.) As for me, I don't plan using it for anything but as a torque, because I have other, less expensive ratchets and spanners to do the everyday stuff. But of course, I'd like to know what it means. It also came with a certificate with data on the calibration and in the manual it says it should be recalibrated at least every 12 months. Calibration is irrelevant if you don't follow the rules to the letter. Most torque settings I've seen were for dry threads - any stray lubricant and you might even twist the end off at the correct torque. --- This email has been checked for viruses by AVG. http://www.avg.com Torque specs vary considerably by application. Some are given as clean and dry, some are given as lubricated with oil - some are given cold, and others hot. That said, I personally have never run across a torque spec that was so "close to the edge" that torqing with "stray lubrication" would cause immediate failure of the bolt by twisting off the end. However, that said, most of my wrenching has not been on bicycles but on automobiles and agricultural and construction equipment which may be slightly more "overengineered" or "overbuilt" Bicycles tend to have less things you can twist the end off. Its common on motorcycles, but mainly pulling the threads out of alloy castings. Its pretty rare to strip an engine down so far that you can put the castings in degreasing plant - torquing the engine case bolts with oil left in the holes is a very good chance of stripping the threads. As for stripping engine bolts, the Honda factory used to install fasteners so tight that a normal person couldn't get them out without an"impact driver". A tool that I never even saw before the Japanese invasion. The lock washers were very effective where used, and the Phipips style bolts were incapable of delivering enough torque to breat them loose without camming out - the Hammer Impact driver solved that problem I believe I've read that the "Phillips" headed screws in a Japanese motorcycle are not actually "Phillips" but some Japanese standard that didn't quite match the screwdrivers we had in the U.S. Which probably didn't help either :-) That's the *whole* cause - just grind a tiny bit off the point of the screwdriver bit and it fits just right. The bits on my Impact driver fit perfectly without grinding. Note I said Philips "style" (I know, I mis-spelled it) bolts. Some of the early Jap stuff didn't use Cadmium plated bolts either - W10 imploded and I had to start over with a replacement news account. So back to old name. The japs were the worst of the lot for cadmium plated fasteners. The very toxic cadmium rubs off on your hands and is cumulative in the body - it causes such acute osteoporosis; you can end up fracturing ribs just by coughing. In the UK - nickel plated fasteners became fashionable about the 80s. They didn't do much about cadmium plated chassis in electronic equipment until RoHS. AFAIK: cadmium batteries are exempt from RoHS - but they've more or less vanished from the shops anyway. Cadmium is very nasty - wash your hands after handling anything plated with it! from Cadmium, A Health Hazard Surface Treatment C. Rehm ESG Einsteinstr. 174 D-81675 Munich, Germany An object containing cadmium is not especially injurious to health on its own. No risk is involved simply by touching it. A potential hazard occurs, however, when such objects are processed and high temperatures are generated. Cadmium plating rubs off on your hands whenever you handle cadmium plated parts and assemblies. Many years ago they even used it on electronic component leads to prevent oxidation - they used more aggressive fluxes in those days. Welding cad plated sheet steel is particularly dangerous - the cadmium is vapourised and becomes airborne. Usually the osteoporosis takes decades to start crippling the sufferer - but I've heard of a repair technician dropping dead after a couple of years from fumes using low melting point cadmium based solder. The specific mode of death wasn't announced. The Japanese know all about it, they discharged industrial effluent containing cadmium into heavily fished costal waters. They even have a name for the disease - itai itai byo. apparently its the noise sufferers make in their death throes. As I mentioned previously - bones become so weak and brittle, you can fracture ribs just by coughing. Well then avoid it as you wish. Many of us recognize the difference between metals and reactive metallic organic compounds. Zinc rich tablets are popular for symptoms of herpes simplex and yet no one welds galvanize steel a second time. Zinc can't be that toxic - its a usual ingredient of baby powder. Never heard of any warnings against welding zinc passivated steel - only know of cadmium plating being very dangerous. You will only weld or braze galvanized steel in a poorly ventilated space ONCE unless you are REALLY stupid. I have never become aware of the dire consequences of welding zinc plated that are being spouted here. "galvanised" can be plated with *ANY* metal that has a higher galvanic affinity than the host metal. Including cadmium and various other toxic heavy metals. Cadmium poisoning is cumulative and has various routes into the body - its a long slow painful journey to a Darwin award. For a few years I worked assembling electronic equipment on cadmium plated chassis - I've seen with my own eyes the extent to which the plating rubs off on your hands. But if you're too stupid to take it from someone who's been there - Darwin awaits you with outstretched arms. |
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