Well, my order of ball joint sockets arrived from Midwest Control Products. Very un-amused.
My first beef with them is what I call shipping rip-off. $20.50 for $6.80 of postage. I’m fine with a $5 handling charge to put 50 items in a small box. $15 is a rip.
Second, I ordered retaining clips ($38 for 25) because the description said they didn’t come with the ball sockets. It was wrong, they were included. Nothing like errors that cost you money to piss you off.
Third, the ball sockets that they sent are missing the internal positioning ring. So when the ball is inserted into the socket there is axial slop to the tune of a couple of mm. Axial slop means the ball moves in and out of the socket by 2mm. This is 12% of it’s diameter. Clearly not a defect, but what application allows a 10% slop factor on a control linkage? Messy.
Which brings me to the title of the post. I had ordered a sample on eBay from a very very nice supplier. It took me a couple of emails to get it and then it showed up once I finally got an invoice via Paypal. It’s a beautiful part with a black oxide finish. When I went back to order more he was unresponsive again, so I went searching and found Midwest. Well, I went back to looking at his part and noticed that it has the external clip, but also a c-clip ring internally that serves to hold the ball captive.
I did some googling of angle joint definitions and DIN and realized that I was looking at a DIN 71802 in black oxide. Further digging shows that DIN 71802 nicely details the mechanical and precise joint. Now, you may be asking, WTF is DIN? Well, I know I asked. DIN is Deutsches Institut fur Normung, or the German Institute for Normal, translated quite literally. This is the German equivalent of ASME. The difference being that DIN is a government function while ASME is a professional association with a penchant for hostaging it’s standards documentation.
One of the things I *really* admire and enjoy about working on German anything is that they are exhaustive in their documentation of standards. A quick leap to Wikipedia shows hundreds of active, withdrawn, and retired DIN standards covering every conceivable mechanical contrivance from pins to lettering to bolts to pipes to angle joints. You can see the list here
Now, I’m only interested in DIN 71802 right now, and you can see a great detail of it here. Fluro® does a great job defining it and helped me realize I have D16 and D19 DIN71802 joints on my bus. It’s like the heavens parted and sunshine emerged. Moving from the WTF is this area to the defined and findable.
A quick search on eBay found a reasonable German supplier with fair shipping rates. A few samples have been ordered. The D16’s were here: http://www.ebay.com/itm/221126178240 and the D19’s are here: http://www.ebay.com/itm/221126167385