How to prevent stripping of frame from overtightening

[Keta]

Cheep PRC screws.

[jurelometer]

One point that folk haven't mentioned yet, but don't know if it applies to this specific  situation. 

With blind holes, the volume of space from the end of the tightened screw tip  to the bottom of the hole is also the maximum volume of excess lubricant that can be in the hole without inhibiting proper tightening (minus a small amount for the trapped air to compress).  The hole turns into sort of a a hydraulic cylinder, and that grease is not going to compress. Good to put the grease on the screw, and not in the hole, and just a bit of grease.

Back to the main question, the purpose of tightening sideplate screws beyond just-snug is mostly to prevent them from loosening from vibration, and there is lots of vibration on power boats.  If using hand tools, you  can usually feel the point where the screw is locking into place.  Just try loosening  the screw at that point and you will get a pretty good idea if it will resist vibrating loose. 

If you ask on the Penn University sub forum, they might be able to tell you the specific torque setting they are using.

https://alantani.com/index.php/board,105.0.html


I don't torque-set reels, but do need to tighten small parts to a specific  setting for other projects.  Being too cheap to buy the proper tool for lower torque settings, I make my own torque wrenches with a 3D printer and tune with a lever and a scale.  After using the torque wrench a couple times, it is pretty easy to get a feel for the proper setting.  For smaller screws (3-6mm) threaded into aluminum, the proper setting is usually the point past snug right before you have to start to muscle up.  Right when that that spidey-sense just starts to kick in

-J

[jurelometer]

I just snug them up. This isn't an application for a torque wrench!

Yup. Keep thinking "aluminum". Use only 2 fingers. If you think they may loosen-up, put some non-hardening thread-lock compound on 'em. Says the guy who's stripped many screw holes... the other day I snapped-in half a line roller screw; steel into steel, wasn't expecting that.

If that screw broken inside the mating male/female threads, probably galling, a common problem with threads in stainless to stainless.  Lubrication can help.

-J

[foakes]

Cheep PRC screws.

I can't stand those cheap screws that seem to come out of everything we get from Asia these days.

Basically not designed to be replaced.

Another point along these lines —-

Having visited (4) reel manufacturing firms —- I have never seen a reel assembly tech using a torque driver for assembly.

I was always taught that experience is the best teacher —- and to just snug up the screw 1/8th turn past the first resistance.  That is just about right.  The other thing is to slightly "reverse-spin" the screw before inserting it just to make sure the threads are catching  perfectly and straight to prevent  cross-threading.  Plus I lightly use marine-grade grease on any screws that will be used in salt water applications.  This makes then both easier to insert plus easier to remove.

Good to remember that these are fishing reels —- not high tech instruments —- just fishing reels.

Best, Fred

[Keta]

I use a inch pound screwdriver for firearms.

I have seen "apes" strip lug nuts and one time one of my co workers broke a 3/4" grade 5 bolt.  For that application a grade 8 bolt was required but he was clueless about bolt grades.

Most stainless steel bolts and screws are made from the wrong alloy, thus gauling, stretching and breaking.  One of the machines at the algae company I work for is stainless, most likely 316, and the half wits have broken or stretched many bolts.  I purchased a 150 foot pound torque wrench and put all of the torque specs on the side of the cover when I rebuilt the machine but they are too lazy to get the torque wrench.  They have broken several 7/8" and 1" bolts using a rattle gun and I have had to put in helicoils on all of the 3/4" bolt holes that secure the bonnet due to stripping.  They do use food grade anti size after me  threatening them with broken fingers.

[foakes]

I do seriously use torque wrenches on all of my automotive and truck repairs and installs..

Plus, I check the torque and tightness on all lug nuts —- trailers, vehicles, hitches, front end parts, brake & axle parts that I work on.  And I verify torque settings even after leaving the tire shop, and specify that the proper torque lbs are used before anyone else works on my vehicles.

Best, Fred

[Keta]

Torking lug nuts is critical.  A well known west coast tire shop broke 3 out of 5 lug studs on my wife's car.  When she go home, 5 miles, she told me she thought they sold her a bad tire. I went and looked and found the broken studd with 2 undbroken ones side by side.  Flopping around destroyed the rim and the tire shop denied the responsibility.  I went there right after finding the damage and they said Mary hit something.  The rim was bent and the holes that the unbroken studs were in were wallowed out...after ,5 miles and 45 minutes.

The tire dealer makes the employees  double time in the shop and they use rattle guns to tighten the nuts.  I quit going there years before and buy my tires from a friend that I do reel repair for. His manager is also has a unit across from my shop and we are friends.  Living in a small town has benefits.

[cathauler65]

Main thing to ensure for all screws into metal or composite is to reverse them once in the hole until the screw thread 'drops' into the hole's  thread - you don't want screws to cut a new thread in composite nor cross threads in a metal hole.