With all of the interest in using aviation elements in hot rods lately, I thought I would show how to safety wire like an aircraft mechanic. Sure you can go buy AC 42:13, but it helps to see it done. All it takes is patience and a little practice. First you'll want to invest in a pair of safety wire pliers. You can find them on the web pretty cheap. Mine came off of the tool truck (yes, there is a difference!) Cost me about $80, but well worth it. If they break I can get a new set next time the truck shows up. My set has lasted me over 8 years of everyday use so far. If you don't know how they work, they have a small jaw that clamps the wire with a built in set of side cutters. On the back they have a knob, when pulled, twists the wire. You will also need some stainless steel safety wire. .025 or .032 diameter will do. And of course you will need drilled head bolts. Just do a search for aviation tools or hardware. I highly recommend getting a catolog from East Coast Aviation Supply Inc. Their catolog is a great reference and they carry everything. All that you have to remember is that the wire always should pull the fastener in a tightening direction. First feed the wire through the bolt and wrap the other end around the bolt on a clockwise direction making sure the ends are even. Find the hole in the next bolt and lock the jaws of the pliers on the wire at the point where the wire just meets the next bolt. Pull the knob on the pliers and twist the wire in a clockwire direction. Pull one end of the wire through the hole in the bolt so that it will also pull it in a tightening direction. Clamp the wire again in the jaws and twist the wires in a COUNTERCLOCKWISE direction this time. Cut off the excess and make a "pigtail" You can also use th "single wire" method for bolts that make a circle like on a flywheel. Or you can use the "double twist" method on the same bolts. Once you get the idea of it, you'll find out that the possibilities are endless. All you have to remember is that the wire always pulls the fastener in a tightening direction.
I was always wondering what the hell those pliers did. Maybe I'll have to find some stuff that I can safety wire just for the hell of it. Nice.
I hate safety wire! Good tech! I just hate doing safety wires because I've done about a million of them on the fighter jets I work on.
It is used primarily on aircraft engines and components to keep bolts from backing out due to vibration. It's sometimes used on certain critical bolts on hot rods, such as aftermarket brake rotors.
Yeah, that's the same reason I hate it too! Not on fighters though, corporate jets. I figured that since I can do it in my sleep it would make an easy tech article!
How many twists per inch? 18 seems to ring a bell. Band aids come in handy too - that wire likes to bite, especially in a blind area when wiring by feel. Works good to secure an oil pump pick up tube w/o having to weld on the pump.
This is a great tech. The kind of thing that I have fumbled with for a while. Now that it has been spelled out I can't wait to go safety wire something. "Where'd that dang dog go?" he he. thanks,
A lot of old flatheads and tractors as well. Kept the bolts from coming out while bumbling down a field. I've tried replicating it a million times over...........guess now I can do it right.
Thanks for taking the time to do this!!!! I have safety wire and no "real" pliers and HAD no clue how to do it properly. Been trying to wire 2 stroke ATVs in the past, now days, it's cross-member bolts on 4x4s..... AL and Steel don't always mix with heat. Now, other than the pickup tube and brake rotors, what other bolts/things would you recommend doing? I never thought of it for the pickup tube - thanks!
They use safety wire on some foreign-built trains. Of course, the shop won't buy those pliers - and (no*****) it's against company policy to bring personal tools to the site. And some of the guys there need to read your thread - it's right on the money! -bill
Cool post! Haven been an aircraft mechanic for two years... I've seen some*****py safety wiring jobs on some nice cars. Guys usually don't get the wire in a "tighten" position. Like this car... absolutely******en car built by a very talented builder... best car at P-Town in my book! BUT... Check out the oh-so-wrong safety wire job... the wire is actually loosening the rear most bolt... and is in a neutral position on the other. In addition, the "wrap around" on the rear-most bolt is in a position to move from one side of the bolt to the other if tension is applied. Also, the wire was not sufficiently turned tight enough as it comes up to the hole in the bolt. And don't forget the tail that is left sticking out straight... that stuff is sharp, and I would have gotten fired if I would have left a tail like that under a plane and had someone cut themselved on it it, or worse yet, if it would have punctured something... Also, I used to wire stuff with a pair of duck bill pliers and twist by hand sometimes. If you are using the pliers only, you need to rotate the pliers one time around after getting the correct number of twists in it to get that slack taken up right next to the hole in the bolt. I almost have to show ya to explain what I mean... I forget how many turns per inch is correct... is it like 8 or 9? Your first example looks like it has too many turns, the middle one is just right and the last one looks right on the turns but loose because there is a little slack there.
Great tip for all those who haven't cut themselves up on aircraft yet! 6 to 8 twists per inch per FAA No need to buy 43.13-1B CHG1 FAA has it online now Lots of great info on hardware, wiring, plumbing, metal, ect... Safetying is on Chapter/Section 7 Pg19 Link to the main page http://rgl.faa.gov/Regulatory_and_G...99C827DB9BAAC81B86256B4500596C4E?OpenDocument
We should all have our cars at the FAA level of inspection. Great post - everyone should learn this, especially if you are ever going to be on the salt or dry lakes.
Ya my buddy....(20 + years A&P and the son of a FAA inspector) showed me how to wire years ago...still very good tech for the rest....Bravo
Another good source for the tools and wire is Aircraft Spruce. They have a free 700+ page catalog and lots of hardware, tubing and other stuff that works on Hot Rods as well as Aircraft. www.aircraftspruce.com Yes, I'm another aircraft mechanic, A&P I.A. specialize in antique and vintage stuff.
Next thing we need ... the "jig" for drilling the safety wire HOLES in nuts and bolts that don't have the holes. The bolts are drilled across the centerline; and the nuts drilled to one side. Here is my "TECH" on "How to make your own safety wire hole jig." It's pretty simple, it holds the bolts or nuts in the "jig" - which is held in the bench vise - with a pilot hole to guide the drill bit. There are different sizes for the different sizes of hardware. Start with a piece of flat stock about 1/2" to 3/8" thick, with holes drilled for the size - diameter - of the head/nut with a slit cut on one side. (at the centerline of hole) The pilot holes - drilled on the EDGE of the flat stock beforehand on a drill press - are positioned over the head/nut. There are two different jigs for each size, one for nuts with the pilot hole offset to the side. And one for bolts with the pilot hole centered. On larger hardware you can actually combine the two together. (pilot holes side by side) Then a "C" clamp is used to "squeeze" the slit closed to hold the bolt/nut while drilling the safety wire holes.
A question to everybody who knows. Would you ever drill thru the nut and the bolt and feed the wire thru, or would that just weaken the bolt to much???? Great tech BTW
Another question: Is 6-8 turns per inch just an arbitrary number or is there an engineering reason for it?
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