My Sofirn SP40 just arrived, and it has quite a strong magnetic tail cap, I wonder if it can pose a risk or affect my cards if I will put them in my “EDC” bag? I am not sure if there are other things I should distance from it, I know a magnet can affect an automatic wrist watch but I don’t put my wrist watch in my bag.
TIA
If you carry a portable hard drive, or other portable media storage, you might want to keep that separate.
Thank you for the info, I carry USB flash drives also. I am wondering if there could be some sort of cover I could use on the tail cap to suppress its magnet while in the bag?
I read somewhere that it is also possible to damage the magnetic strip on credit and other ID cards by placing a magnet near it. As more (credit) cards move towards chips, the less chances of your card being unreadable.
I mostly worry about my automatic watches. I try to remember not to toss my flashlight, wallet and wrist watch in the same basket whenever I get home.
Agreed, from what I’ve read the old style credit cards were damageable by magnets but the newer chipped cards supposedly are not. I wouldn’t chance it personally but ymmv.
I keep my credit cards in an rfid-blocker but as I wear my edc in a holster my flashlight-tailcap-magnets aren’t ever by my cards.
I do not know of a cheap/portable way to block a magnetic field, but it sounds like an interesting topic.
I found that if I kept my keys in the same pocket as a light with a magnet, the magnet would tend to stick to the keys. Very irritating to have the light come out when I just wanted the keys and visa versa.
Personally, I think pocket EDC flashlights should not have magnets on them.
No danger to Flash media. USB thumb drives or camera memory cards - Etc.
But they will darn sure mess up a credit card magnetic strip.
Or the magnetic strip on a subway pass.
Once put a pass-card in my pocket with a mag base light,. Normally kept the card in my shirt pocket.
Watched as my wife got passed the turn-style and disappeared down the stairs.
Me slowing the line as I had to go back to a ticket window.
That ended my magnetic base EDC carry days.
All the Best,
Jeff
I put a hotel key card in a tablet with a folding case with a magnetic closure. Had to go back to the front desk. Also, strong magnets will temporarily affect the programming on a pacemaker or defibrillator putting it into asynchronous mode.
I don’t buy lights with magnets in them, unless they can be easily removed without affecting the operation and performance of the light. I can’t risk the damage to my work ID/security entrance card, and my apartment building entrance card, and my credit cards, and my transportation pass.
i hate it when the light tries to pull keys, knives and whatnot out of the pocket
From my understanding it takes a very powerful magnet multiple passes to affect a magnetic strip on a card. Look it up on youtube.
Google says 4000 Gauss to remove the data from a high-coercivity like a typical credit card. But rewriteable things like hotel key cards only need a field strength of 300 Gauss. And that was my experience where the magnetic flap on a kindle cover erased my hotel key. Frig magnets can be around 100 Gauss, while powerful neodymium magnets could be 14000 or more.
There are a lot of downsides to keeping magnets in a pocket EDC light:
The only benefit is you can stick the light to metal things like the hood of your car.
The magnet can damage a magnetic compass or the magnetic sensor in the mobile phone.
For me, no magnet in the backpack or in the pockets.
I stay away from flashlights with magnets. I have a shop and they pick up every metal filing on the 90 acres then promptly try to embed them in your hand.
Let me come at this from the other direction… While I do not require my EDC to have a magnet in the tailcap, it will get carried more if it does. I find myself all to often either in a mechanical room or in a CER behind equipment racks with poor overhead lighting and I really appreciate having the magnet. Now, I only carry my light clipped in my left front jeans pocket, head down and the only other thing in the pocket is a can of chew.
With defensive carry what it is today… I always carry my flashlight, knives, wallet, ink pen, keys, pistol and mags in the same location, ALWAYS! I prefer to carry my main knife and a clipped box cutter in my right hand change pocket, so given my carry habits I only shop for pants with the pockets I need and that I plan to use. I have watched cops try to run through qualifiers and attempt to load a flashlight into their 9mm in timed rounds. All because they changed the order of items on their duty belt or on their main belt if operating without a uniform. It is embarrassing in a qualifier but would be deadly in real life.
Thank you guys. I will try to look or customize a cover for the bottom part of the SP40 while in the bag to minimize its magnet.
Ymmv, but me personally, I never do.
I got regular/magnetic tailcaps for those Sofirns that’re interchangeable, and never ever ever carry the magnetic version on me.
If anything’s magnetic, I keep it stuck to something ferrous so I can see at a glance that it’s magnetic.
Have 2 magnet cap lights in my right pocket at the moment — EO2II in watch pocket and TS21 in jeans pocket with wallet. Have had several over the years and have not had a problem with any card that I know of. Doesn’t bother me except for when I carry my SC31 pro in my jacket pocket with my keys. Several times now when going to unlock my house I have launched the light onto concrete steps and then concrete patio. No shelf queen for me 
Typically I find a good clip more useful than a magnet. However, sometimes the magnet is just what is needed. The EO2II in a rack enclosure for tracking wires etc is pretty much the ideal tool for the job with the magnet.
I order non-magnet tail caps for all my lights that come with mag caps by default, and only use magnet cap on one light (DT8 219B) that I know I’ll need magnet cap on it.
Strong magnets are serious threats to all sorts of things. Especially automatic watches, unless your automatic watch is a new Omega.
The “trinity” (Patek, Vacheron, Audemars) are not embracing the idea of magnet-proof movements, so I’d say take care if you own anything from them.