Have a look at my tool... For torquing nuts.

This is straight from boeing 747 maintenance manual. This is what I have been using for 26 years as an aircraft engineer for torqueing fasteners on aircraft. So if it's not right that an adaptor set at 90 deg doesn't need to have new toque setting calculated then ther is a lot of aircraft out ther with incorrectly torqued fasteners.

Hope no one out ther has a fear of flying.... :shock:

Indicated torque has factors other then fastener tension. Tension applied by the fastener is what is critical, not the torque used to turn the fastener. Since it is difficult to measure tension, a torque figure is used. If the fastener threads are clean, not damaged and the surface under the fastener head or nut is also clean, smooth and flat, the specified torque will apply the correct tension. Also, in a blind threaded hole, fastener length is critical, as well as excess lubrication. Of course, the old tried and true method of tighten until it strips, then back off a ¼ turn is the method preferred by some.

SteveA requested a UK supplier for MotionPro - OffRoadOnly , this is where I got my Adaptor:

http://www.catalyst-findit.co.uk/index. ... ce3b506f73

£30.55 ex VAT + Postage

Regards

Mike

JimC hit a good point on lubrication. People tend to be very generous with lube on the threads (threadlocker, oil, thread sealant, anti-sieze are all lubes) which tend to up the applied torque a fair bit. Powder at the bolting interface also doesn't help with that, nor does soft crappy split lock washers in places that need hardened ones.

People also tend to make my life difficult and thread every fastener into every crank case 9 times as tight as it should be :|

Only one way to get torque right, measure bolt stretch, period end of story. Manufactures test batches of fastener and clamped material then publish the ballpark to aim for to mass produce. Same thing for particular engines, trial-error to settle on safe effective average reading of t-wrench. Worn threads, distorted treads, dry threads or lubed threads can throw off real meaning of t-wrench. To confuse-refine sense of satisfaction preaching how to apply-calculate torque values consider the picky technical scientific guys building garden tractor side valve air coolled push rod race engines that monitor the temperature of parts and fasteners being assembled to calibrate for proper clamp and stretch. Speed of twisting and shocking or not matters a bunch too. So which variable applies most in your variety of Nortons? hobot's flippant attitude comes from measuring stretch of crank and rod bolts charted against torque shown, so what evidence to the scientific builder have to counter point? Got naked engine cases handy to finally get around to charting cylinder and head fasteners to calibrate my angled joint proprioceptors.

The real torque issue is how much stretch on each type and size fastener to seek which is what guides brain scrambled hobot to keep his t-wrenches like new.

Only one way to get torque right, measure bolt stretch, period end of story.

Click to expand...

Where do you think the stretch specs come from? It's tension, my man. PERIOD!

Where do you think the stretch specs come from? It's tension, my man. PERIOD!

Click to expand...

Well yeah, in general one can guesstimate stretch by the torsion but with the variables in our ancient craft I've measured 5 lb ft difference from manual to get best stretch. Its a nit picking subject that ain't very critical but for crank and rods. Seriously a real mechanic should chart torque vs stretch on some significant fasterners and post it here to get sense of scope of trusting t-wrenches to do its duty. I do seek some double checking on my findings.