Drilling small nuts and bolts for safety wire

[PiperCub49]

I have a paramotor that I want to safety wire a lot of small nuts and bolts on. The bolts are four and five millimeters. Does anyone have experience drilling these with a safety wire jig or with any other method? Any advice?

 

[rpcraft]

Get small drill bits, a drill press, and do some googling for a safety wire jig. It's been a while since I concerned myself with safety wiring but you want to make sure your hardware will withstand having holes drilled into it and not lose it's strength and not have compromised clamping ability, especially on small hardware.

 

[LeeG]

Summit Racing has a jig set.

https://www.summitracing.com/parts/otc-4794

 

[SeisMec]

Grade 5 https://www.mcmaster.com/safety-bolts/steel-wire-lockable-hex-head-screws/


Stainless Steel https://www.mcmaster.com/safety-bolts/stainless-steel-wire-lockable-hex-head-screws/


Stronger than grade 8 https://www.mcmaster.com/safety-wire-bolts/

Edit: My bad those are all SAE

 

[lolaetype]

Get the best quality drill bits you can find. I don't know why, maybe bad technique, but I've broken more small bits drilling bolts for safety wire than I have for anything else.

 

[RTM]

Dunno, I think if falling to my death was an option, I’d look really hard for those special bolts and castle nuts, and pay extra for them. A lot extra.

I just threw away about a pound of (probably) SAE wired fasteners, most of which were CAD plated, lots of odd stuff, think they were take offs from radio towers or some such.



And yes, I realize they are hard to find, especially in small Metric sizes. Good luck either way

 

[matt_i]

If you have a jig perfect.

If not I would resort to the milling machine with a solid carbide spot drill, 120 degree included angle. With the axes locked up you can place the hole exactly where you want it. Then a standard 118 degree drill bit following in the conical pocket will take care of the rest. Its a lot of manual tool changing but its also very reliable in my experience.

 

[RoninB4]

When drilling small holes it is important to be very careful when the drill is breaking out the far side. This is especially true if drilling through a "corner" instead of across the flats. As the drill emerges from a "corner" one lip is cutting air, the other is still cutting metal. This often causes the engaged lip to bite into the metal more than it should, if it bites enough the drill will break and the hole won't be round. This can/does happen on large drills as well. If you'll be using a drill press with a quill stop you'll want to set the stop just above break-through and advance the stop about .015 at a time in a "peck cycle" to avoid having the drill pulled into too much material for it to cut. Yes it's a PITA and takes longer at the end to do it that way but some operations are just that way. If you'll do this in a mill with a quill you should already know to do this. Failure to use this method or using a hand drill will likely result in broken drills and ruined fasteners. It's even worse if the fasteners are SS by nature of the material. Would not use carbide drills as carbide does NOT flex like HSS and tends to shatter. This is especially true for carbide drills under 1/16. Digging out chunks of carbide in a small hole is almost pointless. Not saying it can't be done, I have, but for the average person a HSS drill will be more forgiving, less likely to shatter, and can be re-sharpened much easier. There are other options/strategies if you're willing to make your own fasteners but that's another topic. Hope this helps someone.

 

[brtsvg]

Save yourself the time and trouble of drilling and go with readily available AN-standards aerospace-grade hardware that comes pre-drilled.

 

[Air21]

Now's a perfect time to buy that EDM machine...

 

[nafterclifen]

See if you can buy pre-drilled hardware here...

https://www.probolt-usa.com/

 

[bczygan]

Use pre-drilled AN aircraft hardware.

Bill

 

[driz]

Use pre-drilled AN aircraft hardware.

Bill

Aircraft Spruce And Specialty Company. They’re online and have EVERYTHING. Even stuff they don’t list online . When it comes to hardware that’s where I always bought mine and they don’t kill you on small orders, at least in my experience . It has been 10 years since I used them though. And no they won’t mind if you don’t have a plane[emoji847]


Sent from my iPad using Tapatalk

 

[mazdeuce]

Depends on the bolts and whether they have enough meat to drill across or if you have to drill corner to corner. Or even better, cap screws, those are easy especially in the sizes you're talking about. You can do all of it by hand, but a jig makes it easier. Even just throwing together something to hold the bolt still while you drill will make your life a lot better. You're going to break drill bits and at least some of the time you won't be able to get the piece out and that bolt is now junk. Prepare for that.
I don't do aircraft, just motorcycles, so take what I'm saying with a grain of salt. If I had to wire something that was going to fly, I'd certainly consider an order to an aircraft supplier for pre-drilled hardware.

 

[motoretro]

I did some 5mm socket head bolts awhile back for a Motorcyel. While a jig would have come in handy, I did them with a drill press and DP vice. I drilled for .032 wire and eyeballed it when drilling. My eyes are not that great anymore so I goofed up one. I did get the job done, de-burred the holes and everything came out fine. I used a punch to help avoid wondering of the bit. The bolts were just a hardware store variety in regards to grade. The safety wire tool does make things easy. McMaster Carr supplied mine.