Had a lamp that got smacked into a post here, broke, so I thought I would take advantage of the misfortune by showing you the parts we use. This belongs to a Flower Power FR40T12 but it is the same lamp end we use on all T12 lamps. Extremely beefy parts that allow us to take a lamp designed for 40 watts, and push it all the way to 100 watts if you want. The part itself is actually a stolen design from my days in the tanning industry: essentially the same part we used on high end 120 watt tanning lamps. It is obviously a bit more expensive than using generic F40 ends, but it means the lamp won’t die prematurely and can operate on a wider range of wattages: Use them as you like, they can take it.
Here you can see the beefy posts and the heavy heat shield. This protects the glass, makes them less likely to get black ends (killing phosphor) and extends the life, particularly if you overdrive them.
Another angle shows the coil. We actually use a preheat coil for compatibility. This means it will work with any ballast: old choke or magnetic ballasts, or new program start, instant start or high frequency electronics.
The short of it is that we use the beefiest, sturdiest parts that money can buy when building our lamps. They won’t die early or fade out when you need them most.