BC Precision (2 Pack) 2" Inch Chrome Steel Bearing Balls G25

Very well made

Started with 1.5 inch then graduated to the 2 inch balls. Nice and heavy, feels great. Great cross training for anything that needs strong but sensitive hands like massage therapy or martial arts. Warm up with these and any weapon you train with afterwards feels a lot more connected to you.

I got these to use as 2" baoding balls (Chinese exercise balls) for hand therapy, wanted something heavier than my traditional hollow ones with the bells inside. First off just wanted to say mine did not have any rust on them and have a mirror finish. I cleaned the grease off with three steps, Gojo mechanics soap, followed by dish detergent, followed by rubbing alcohol, then dried them off. This got them very clean, so clean these squeaked when using them at first.I simply wanted good quality polished steel, nothing chrome plated that could chip off, when searching solid baoding balls they all seemed to be plated. Well these are legit AISI 52100, same steel used in ball bearings, same quality control, with the same mirror finish, because they are actual huge ball bearings. Go to the BC Precision Balls website, and under their chrome steel ball bearings category you'll find a description, "Chrome steel balls demonstrate high hardness, resistance to deformation, and excellent wear characteristics. Chrome balls from BC Precision are manufactured from the highest quality chrome alloy steel and through-hardened for maximum strength and service life. Applications that are ideal for chrome balls include tumbling media, spray can agitation, ball bearings, drawer slides, writing instruments, vibratory finishing, linear motion components, check valves and locking mechanisms."So there you have it. About the same price as the other solid baoding balls, with way better quality. Very happy with my purchase. The shipping was fast too by the way, despite not being prime shipping.

These are heavier than I thought they would be. I made a very hefty and dangerous monkey fist out of one of these 2" balls. After holding my finished monkey fist around my wrist I have no doubt it would knock an intruder out with ease. It hurts just letting it swing into my shins. It is like holding a wrecking ball in your hands. For those of you buying these for making monkey fists and are thinking about getting an even bigger ball don't. This is plenty heavy as it is. Any bigger would be too slow to swing. I'm 6 foot tall and 230lbs. I'm not all muscle. I'm chunky but I do lift heavy and I am strong. I think the most practical diameter for a monkey fist is 1.5" if you want more speed which is more ideal in a self defense situation. 2" is just right for my size if you want more power behind it. For kicks and giggles I still might make a 3" or 4" monkey fist, but for a practical less lethal home defense weapon I wouldn't go more than 2".For other users it really does have a mirror finish. Received both of mine without any scratches. Pretty desk ornament or functional bearing for heavy machinery.

The diameter of each is precisely 2 inches (50.8 mm) and each is 536 grams (1.182 pounds). The chrome plating seemed to be uniform.They came with a waxy oily coating (something sticky) and washing that with mild soap revealed dark spots and discolorations. It looks to me like they are very thinly electrodeposited chrome.They seem to be soft magnetic. A magnet will pick them up, and they transmit magnetic field strongly. And seem to retain the field. A bit of looking (after buying them) shows many sites that explain how magnetic. The term is "ferromagnetic" meaning they can retain a fairly strong field.For what I wanted (a pendulum weight) this will cause problems, because the rate of swing will vary according to the natural magnetic field, and anywhere nearby there might be other magnets. Since I use a lot of magnets, that is pretty much everywhere.Why did I not look before? Well, truth be told, I have no way to verify the content of these things. It might be a reputable supplier, but they might get the material from anywhere. It seemed too much trouble to trace out the provenance of such a simple thing - by searching the Internet - when that could all be false. So I bought a pair.I must say, when I weighed them on a little kitchen scale, I was surprised they were exactly 536 grams. And when I measured them with a caliper exactly 50.8 mm (the world is supposed to be on SI units now. You would think corporations would get on board).Anyway I cannot use them for my intended purpose. I somewhat dread looking for "stainless steel". I have some glass spheres that will work, but they are low density. Copper spheres are too conductive. I found some "bullet weights cannonball" lead fishing weights. They are rather roughly made and I have no idea what is inside.One thing I have not really addressed is how to drill a hole in them to hang them. I hate to buy a drill and bits just for two holes. That is the state of the world now it seems. Simple things can take forever to try, just because it is so hard to find, and trust, sources for materials and things.I don't think there is any way to have conversations, or ask questions of other people on Amazon. I have suggested it. Think of all the millions of people with so many backgrounds and skills, and no way to ask anyone for help, except on a product page. If there are hundreds of suppliers for something do you ask the same question on every product page? There has to be a better way.The surface is reflective enough and uniform enough to take photos in the curved mirror surface.I can use small strong magnets to hang them. I just don't have a good way to map the magnetic field. or the hysteresis of the material. A good problem, but some other time.I guess I can use them for hand exercises. Arthritis.Oh. The density is 7.8086 grams/cm^3 and the average value on the web is about 7.73 g/cm^3The density of chromium is 7.15 g/cm^3 so adding more chromium would make it less dense, not more.

If you use a Bambu AMS unit, these super heavy balls weigh down the roll so the rollers can get more traction on the spool. Works 72% of the time, the solution is to print the spool adapters for cardboard spools and use this ball.

It should be noted that these balls are not stainless steel. 52100 is a high carbon, low chromium alloy. If not properly cared for, these will rust. If you want a full stainless ball bearing, search for 440 stainless. I forged these out into knives. 52100 steel holds a fantastic edge and these are great for that purpose, but must be cleaned and dried after use to prevent corrosion. Product arrived in a timely fashion.