Hi All:
For those who advocate silver soldering or welding these. there are a couple of problems you would need to overcome:
- First, these parts are pretty small so fixturing them would be an interesting challenge.
Nothing that can't be overcome, but a challenge nonetheless.
- Second you'd need to make the fixture out of something heat tolerant...maybe inconel or titanium.
- Third you need something that solder doesn't stick to readily...inconel or titanium.
- Fourth your fixture needs to maintain the proper solder gap.
- Fifth, your parts need to be heat treated at some point, so you have to make them out of something that retains hot hardness like H-13 and use a low temperature solder, so you can harden them first and then solder them together.
That's a lot of problems, and you need to do it at some (thankfully modest) scale...at least 50 or 100 of these parts for the first run.
Laser welding them creates a different set of challenges;
- First, the penetration and therefore strength is not great unless you really pour the coals to it or vee the joints and use filler wire.
- Second, welding it puts a fillet at the joint...you don't want a fillet at the joint.
- Third, you have to fixture them as with soldering.
- Fourth, the quality of the weld depends on the quality of the process control, so to do it reasonably reliably you're talking CNC laser welder in an inert atmosphere and etc etc.
- Fifth, welding hardenable steels is problematic (hot cracking) so your material choices are restricted to something you can case harden or nitride, or else you need to develop the welding process so you can get reliable welds.
You can see where this is going cost wise.
Given that; casting them, coining them , EDM burning them, all start to look more attractive.
Of those coining remains the most attractive to me because the process is so simple and predictable (and cheap).
The OP can make the dies cheaply and easily and give it a go without investing much more than a bit of S-7 and a half day of time.
I wouldn't be surprised at all if that's how they were originally made 140 years ago...coining has been around for a very long time.
Cheers
Marcus
www.implant-mechanix.com
www.vancouverwireedm.com