Just realised that I hadn't replied to
@ChaiLatte and
@Fergie 307 .
Firstly, thanks to ChaiLatte I know know what to ask suppliers of ball bearings in the USA ( who are far far cheaper than any UK or EU ones , even taking into account shipping and customs and TVA ) for, as regards to type of steel.
What I need them for..making the joints in skeletons / armatures for stop motion poseable claymation animation characters, the drilled and tapped ball bearings ( we'll have to do the drilling and tapping ) are attached to various lengths of threaded steel rods, The ball bearings are then held captive between two small short steel plates ( which I can get "off the shelf" very cheaply ) which have holes slightly countersunk holes at each end and another smaller hole drilled and tapped in the centre of each plate . The ball bearings are set between two of these plates , with the plates positioned countersunk holes facing each other, the third ( centre hole ) has a grub screw , with allen key head going from one plate to the other. The ball bearings ( with threaded steel rods attached ) are held "captive" at each end of the steel plates by the countersunk holes "cupping them", but they can swivel and pivot in their respective "cups" if the centre grub screw is unscrewed a tiny amount so as to relax the hold of the "cups".
Imagine these inside a plasticene figure's joints..If you want to bend the joint, you turn the grub screw a fraction ,reposition the elbow or knee or hip or wrist or neck or ankle ( or "whatever" joint in a non human character ) , then you re-tighten the grub screw and the joint is locked. stop motion requires between 20 and 30 frames per second of "action"..Some characters can use many of these "joints", buying them is very expensive, currently no companies will ship the ready made skeletons or the joints to the EU at less that prohibitive prices . Custom skeletons for non human characters can cost hundreds of euros. So we need to make our own ( my son is an animator / cartoonist ) , we also have an EU market to supply them to amateur and pro stop motion movie makers.
I can easily set up a bench drill to drill the bearings ( thanks to knowing which type of steel bearings to ask for thanks to Chailatte ) and threading them is also easy .The threaded bar ( stainless ) I already have large stocks of from 2mm up to 10mm for heavier skeletons. Normally the larger ones are made from lighter materials such as wood anyway, imagine puppets or marionettes with lockable joints, basically movable wooden sculpures which can be "clothed" with plasticene or foam or "clothes". some incorporate rare earth magnets , leather straps and other ways of creating movable parts. not all marionettes and puppets are strung, some are worn .Think Muppets, Dark Crystal or Chinese Dragons, or Little Amal , or some of the huge ones used in France.
https://en.wikipedia.org/wiki/Giant_puppet
https://www.theatlantic.com/photo/2012/05/the-giant-marionettes-of-royal-de-luxe/100293/
There are all kinds of puppets and marionettes, from the tiny , to the huge, some move, some don't, many are made of wood, or incorporate wood, a very interesting , creative and rewarding type of sculpture.
Hopefully the youtube video ( which it turns out will not allow "embedding" ) but can be seen with many others at the original youtube page is not geo-blocked for many here.
Apologies for the thread "hi-jack" in replying to Fergie 307 in detail, and thanking ChaiLatte .