One of the most popular pens of all time, the Parker 51 remained in production for over thirty years and sold in huge numbers. The barrel and hood were made of Du Pont Lucite, a tough early acrylic. The later Aerometric fillers are often ready to write without service even today. It is a tough, durable, practical pen which has an immensely strong following today. Many people wax enthusiastic about their 51s. Some get quite fanatical!
At this point, I should say that I’m not one of them. In the last two years, I’ve sold one Parker 51, and that was only because it had an oblique stub nib.
I have several objections to the Parker 51, and some of those would apply to the 61, the 21 and the various clones made by other manufacturers. First off, I dislike hooded nibs. Much of the beauty of a fountain pen, for me, lies in a well-designed exposed nib. Also, I dislike pens that taper towards the writing point. It feels like your fingers are slipping forward all the time, and it forces a strong and ultimately painful grip. This is a problem common to all pens of that shape, especially Parker’s flighter ballpoints. It’s possible to create a tapered pen with a good grip, like, for instance, the Sheaffer Balance. The Parker 51 is just plain ergonomically wrong.
The early ones are Vacumatics. I’m forced to say that the Vacumatic is an unfortunate filling system, an unnecessarily high-maintenance bulb-filler with a baroque complexity that adds no advantages to the simple original. Novelty was perceived to be a selling point in American pens in those years, and the consequence has been that we have an inheritance of grossly over-engineered filling systems that have a short time between failures and are finicky to repair. The later Aerometric is an infinitely superior filling system.
My oblique stub nib was a considerable rarity. Most Parker 51s, whether fine, medium or broad, have a rounded nib. Taken together with the nib’s stiffness and the relentlessly measured feeding of ink by the collector, the effect is very similar to writing with a ballpoint, hence, I believe, their popularity among those who have never used a traditional fountain pen with its beauties of line variation and shaded ink delivery.
Your view may vary, of course 🙂