Nice calculator but it is irrelevant for anything other than odd angle that would never be use for a barrel or castle nut. It doesn’t matter how long the extension length is if it is turned 90 degrees to the wrench it will indicate the set value.
Have been using calculations for torque for over thirty years in the aircraft world.
The biggest thing to remember about torque is that all values, unless otherwise specified are “dry” torque values.
If an anti-seize is used the torque value must be reduced. There are values for each size fastener.
Generally the reduction is about 22%
Off topic but a question for you. I grew up near an Army base for fixed wing aircraft. We befriended a soldier who worked on the planes and he gave us buckets of bolts he said because they could only be used once and were thrown away. Is that true with civilian maintenance or just a military thing. Thanks in advance.
Yes. In aviation applications there are many fasteners (especially self-locking types) that are one-time-use if they are in critical areas, flight controls for instance. May be found in specific aircraft manuals and also standard practices manuals. Additionally, self locking nuts will many times have to pass a mininum tare torque in order to be re-used.
One thing that should be accounted for when you are applying specified torque is “tare” or run-on torque. This is the torque necessary once all of the threads are engaged. This “tare” must be added to the torque value to ensure you are getting the proper clamping pressure. Many self locking nuts have considerable drag or tare torque and not accounting for it can result in a serious under-torque on the fixture.
Torque and fasteners are a very interesting and sometimes complex topic, which is why the mil manual makes it simple. Use their wrench, their lube, their diagram, their torque values.
Another dual headed bolt where the first head shears off when correct torque is achieved and second head is there for clamping force and removal. Hell, had a toilet seat made like this once.
Another bolt that had a tit on top of it that got pulled down level with bolt when torqued correctly. Much like the smartbolt.
Another that had a gauge built into the head.
Mostly in crane/ship loading equipment securing the ring gears where it rotates.
There is a whole other world of specialty fasteners out there.
FWIW when I was on the T700 Apache/Blackhawk gas turbine engine assembly/test line, GE Aircraft Engines got so advanced with their fasteners, process/technique, etc., that most torque was applied using wrench arc procedures. Tighten to seat/snug, apply degrees of additional wrench arc. This demanded 1-time use fasteners.
Thank You,
My google fu was weak all I came up with was descriptions of what cNm was but no chart.
It’s weird they sell a tool calibrated in a unit of measure that NOT included in their own conversion charts.
Back to our regular schedule thread…
When doing conversions, I learned to write them as a fraction (over under) in a single line, and write everything to cancel units (top to bottom cancels) until you get the units your looking for. It’s very helpful for stuff like that. Especially helpful for longer conversions or equations that tend to lead to simple mistakes (dividing instead of multiplying, etc). Might seem like common sense to some, but hopefully it helps someone. I can post an example pic if that wasn’t clear to someone.
