Just one of those abrasive composite discs for cutting metal. It says on it to use by such-and-such month 2026. Why?
Probably the resin used for bonding it eventually turns brittle with exposure to air, light, etc; the date is probably set on the very conservative side of that reality and may also be there to ensure that stock rotation happens.
And not to belabor the obvious, but: those things spin really, really fast. They could injure you if they break, especially if you fail to wear protective gear. So there is probably some element of avoiding legal liability in case some 20-year-old disc shatters and takes out the eye of someone dumb enough to not wear eye protection.
This. All such composite abrasives have an expiration date. Despite the risk people do use them for years past that date. They are spinning at a high rate of speed in contact with the material they’re grinding. That creates a great deal of vibration and some amount of heat, although most of the heat is carried off as sparks, which then protects the material being ground.
Something a lot of people don’t realize is that child car seats also have an expiration date for the same reason. After a while the plastic can become brittle and may not be able to withstand the forces from an accident.
If you’re ever getting a second hand car seat, make sure to check the date. Off the top of my head, it’s less than 10 years. By the time someone has used one for 1 or 2 kids and then leaves it the garage for a few years, there’s a good chance it’s past, or close to, it’s date.
A youtuber I watch has mentioned that one of the reasons he uses pneumatic grinders/cutoff wheels is specifically because they’re more likely to stall before they tear themselves apart if they bind up.
Also, keep the guard on it. And, personally, whenever possible, I always try to hold it so my body isn’t in the same plane as the disc (though sometimes that results in an awkward angle that would make the disc more likely to break apart).
And motorcycle (and bicycle) helmets:
Same concept, which is why I’m assuming it’s an okay addition in an FQ post.
Yeah, I had people berate me for keeping the guard on my angle grinder when I used it in a video; apparently I am a dork because nobody does that. I am, however, a dork with ten fingers and two eyes.
And there’s way too many pictures out there of people with half a grinding disc stuck in their chest or arm or face.
Those things don’t fuck around.
Yes, this. Especially, hold it so eyes and face and head are well out of the plane of the disc.
It’s kind of automatic for me, when using a hacksaw or carpenter’s saw, to be watching from the plane of the blade to guide the cut. But realizing that this is insidiously dangerous with a fast spinning cutoff wheel makes it fairly easy to avoid whole categories of disastrous injuries.
Hard hats have a little five year dial molded inside the brim to show when they need to be discarded. Body harnesses have a calendar tag for the same reason. Regardless of condition, out they go.
Grinding wheels (said to be the first thing an OSHA inspector looks for because people do take the guards off so often) can be given a ring test to see if they’re solid
Wheels should be tapped gently with a light nonmetallic implement, such as the handle of a screwdriver for light wheels, or a wooden mallet for heavier wheels. If they sound cracked (dead), they shall not be used. This is known as the “Ring Test”.
In a shop setting, or a home with kids, a good “best practice” is to put a lock-out/tag-out cover over the disconnected plug, to keep untrained people from damaging the wheel by using it on sheet metal, “adjusting” the guards and tool rest, etc.
Presumably this wouldn’t apply to natural stone wheels? (Though I’m thinking here more about sharpening wheels like Tormek, not angle grinders, so maybe it’s outside the scope of the question?)
Do they even make natural grinding wheels? If they’re comparable in price per weight to my Dan’s Arkansas whetstone, they’d be prohibitively expensive for most, certainly. I’m sure at one point in history, though, natural stone wheels were all they had?
Don’t know for sure. Some manufactured wheels are advertised as ‘natural stone’ meaning a composite using some ground natural stone instead of a processed abrasive. One I saw advertised that might actual be made from a single chunk of natural stone was very expensive, something like $100 for a 2" wheel.
ETA: Just looked online for one, maybe what I saw before. It’s $104.90 for a 2" wheel and claims to be made from Arkansas Stone.
When did they start putting dates on these?