Prop bolts....what's the consensus?

[pawnshopmike]

I only use Grade A Certified Rubber Prop bolts. Works just like prop saver bands.

 

[Jetpainter]

Once I removed the prop from the hub, the three broken bolts were a couple of threads deep into the hub so I was unable to get a grip and back them out. I don’t carry the tools to deal with something like this to the field so my day was done. The pic below shows the broken pieces, probably about 12-15mm length.

Been there, done that. Luckily I had a nice pick in my field box and we found a tiny little hammer in the Quonset hut at the field and I was able to remove them there. Thankfully they weren't Loctited or the 200 would have been on it's way back to DA.

And I agree guys, very interesting stuff!

 

[Judge]

One thing I advocate is to use a torque wrench on prop bolts and to check them before each day's flying. Properly torqued bolts will go a long way to avoiding issues that loose bolts can cause. No matter what bolt hardness you are using, improperly/unevenly tightened (torqued) bolts which loosen are the leading cause of bolt failures.

 

[dhal22]

As a plumber I tighten things up constantly. I have never used a torque wrench on prop bolts and never had a bolt come loose either. Perhaps a good feeling for tight is working for me.

 

[Snoopy1]

All very interesting my single question is what or who's torque wrench are you using. Very interested to know. One question do you torque your carbon and wood props differently.

 

[Judge]

As a plumber I tighten things up constantly. I have never used a torque wrench on prop bolts and never had a bolt come loose either. Perhaps a good feeling for tight is working for me.

You likely have a calibrated touch!! But to be clear, I am not saying that unevenly tightened/torqued bolts ALWAYS fail, but in general, failed bolts are very often not properly and evenly tightened.

 

[dhal22]

Mine are evenly tightened. I slowly tighten on opposite sides as I work around the hub. Tighten until I don't trust the next turn from stripping the threads.

 

[Judge]

I am a simple guy. Most engine makers publish prop bolt torque, so that's what I use. Seems to work for me. YMMV

 

[Capt.Roll]

All very interesting my single question is what or who's torque wrench are you using. Very interested to know. One question do you torque your carbon and wood props differently.

I use the 1/4" drive torque wrench from Harbor Freight; very economical. If I remember correctly their +\- tolerance is 4 percent. When I purchased mine I checked it with the calibrated torque wrenches at work. It was dead on accurate through the mid-range settings; 30-80 inch pounds. At the extreme high and low settings it was within the 4 percent error. I've had it for several years and it has been trouble free. For installing cylinder head bolts, spark plugs, crank case bolts, and prop bolts it work great.

There are certainly more expensive wrenches (Craftsman, Snap-on, CDI and more) and if I used a torque wrench on a daily basis I'd most likely have one that may be better quality.

 

[Judge]

I use the 1/4" drive torque wrench from Harbor Freight; very economical. If I remember correctly their +\- tolerance is 4 percent. When I purchased mine I checked it with the calibrated torque wrenches at work. It was dead on accurate through the mid-range settings; 30-80 inch pounds. At the extreme high and low settings it was within the 4 percent error. I've had it for several years and it has been trouble free. For installing cylinder head bolts, spark plugs, crank case bolts, and prop bolts it work great.

There are certainly more expensive wrenches (Craftsman, Snap-on, CDI and more) and if I used a torque wrench on a daily basis I'd most likely have one that may be better quality.

That is exactly what I use. Cheap insurance to remove any doubt that things are properly torqued down.