Parker 51 Mechanical Pencils, Full Versus Demi Sizes?

[Drone]

Hello P51 Aficionados,

I just received from Anderson Pens[1] a 3Q 1948 ("MADE IN U.S.A. 8." date code) push cap-actuated Parker 51 mechanical pencil with a smooth (no barrel ridges) Navy Grey lucite barrel, lustraloy cap, translucent grey finial jewel, six cone bands, and a gold plated clip (see the photo below from the Anderson Pens site.). According to parker51.com[2], these type of push cap-actuated P51 pencils were made from 1948 through 1957. I paid $25 plus shipping for the pencil, which seems reasonable to me given Anderson Pens is a professional restorer & seller.

With the lead fully retracted and the cap fully seated this pencil is 5 3/16" (131.76mm) long. I think this is a full-sized pencil (not demi), but I'm not sure.

Question: What are the correct lengths for the full and demi size versions of this P51 pencil?

Bonus Question: Does anyone know where I can buy a replacement eraser (rubber part, not the metal ferrule)? The vintage eraser stub now in the pencil is 1/4" (6.35mm) in diameter. The metal eraser ferrule is 5/16" (7.94mm) long.

Thank You, David in S.E. Florida

References:

1. https://andersonpens.com/parker-51-grey-mechanical-pencil-2019-0517-60

2. http://parker51.com/index.php/51s/pencils/k

 

Edited May 21, 2019 by Drone

[FarmBoy]

The difference between a Demi and full size pencil is the cap. The barrels and mechanism are the same.

[Drone]

The difference between a Demi and full size pencil is the cap. The barrels and mechanism are the same.

 

Interesting - I did not know that. Thanks, David.

 

So ideally what I'm looking for is the difference in cap length between the demi and full-size P51 pencils.

Edited May 21, 2019 by Drone

[mitto]

A demi and a full size.

 

 

 

 

[ajcoleman]

FYI, I have found the eraser from a disposable bic pencil is a pretty good fit. They are only a couple of bucks for a dozen pencils and the eraser pulls right out. A bit of a waste perhaps, but I have not found anything that works for less money.

[Drone]

A demi and a full size.

 

This is what I am looking for. The cones appear to be different sizes not just the caps. Will you please measure the lengths of the two pencils for me? Thanks, David

Edited May 30, 2019 by Drone

[Drone]

FYI, I have found the eraser from a disposable bic pencil is a pretty good fit. They are only a couple of bucks for a dozen pencils and the eraser pulls right out. A bit of a waste perhaps, but I have not found anything that works for less money.

 

Is this the BiC pencil you are referring to?

 

https://www.amazon.com/BIC-MPEP241-Blk-Ecolutions-Xtra-Life-Mechanical/dp/B00347A970

 

Edited May 30, 2019 by Drone

[Drone]

A demi and a full size.

 

IMG_20190526_212124.jpg

 

@mitto, I took another look at your picture. The nose cone on my pencil is identical to the cone on the demi pencil in your picture. So definitely my pencil is a 3Q 1948 Navy Grey P51 "Demi". FYI here are all the dimensions...

 

3Q 1948 Parker-51 Pencil Demi-Size:

 

With no lead installed and the lead clutch mechanism fully retracted into the nose cone and the cap fully seated this pencil is 131.33mm (5 11/64") long. Nose cone dimensions: 22.46mm (7/8") long, 6.05mm (1/4") dia. at widest, 4.95mm (3/16") thread dia. at widest. [Note: Remove the piece of lead from the internal clutch mechanism in order to safely unscrew and remove the nose cone.] Cap dimensions: 57.63mm (2 17/64") long from cap lip to the apex of the finial jewel, 10.31mm (13/32") dia. at the cap lip.

 

I still wish I had an accurate length for the full-sized pencil, but extrapolating from your images the larger pencil should be around 144mm (5 2/3") long.

 

Thanks again for providing the picture. David

[Drone]

 

Is this the BiC pencil you are referring to?

 

https://www.amazon.com/BIC-MPEP241-Blk-Ecolutions-Xtra-Life-Mechanical/dp/B00347A970

 

 

I bought some of these pencils. The erasers are a little too big for the ferrule in my P51 pencil. But a minute or two of rubbing the eraser down on a rough piece of paper narrowed the diameter so now it fits perfectly. Thanks for the tip - David

[wvbeetlebug]

 

I bought some of these pencils. The erasers are a little too big for the ferrule in my P51 pencil. But a minute or two of rubbing the eraser down on a rough piece of paper narrowed the diameter so now it fits perfectly. Thanks for the tip - David

 

This is a fantastic idea. What lead are you using?

[BamaPen]

I haven't seen anyone provide the dimensions here, so here's what I have:

 

I have two P51 pencils, both in sets with matching pens, one standard and one demi, both aerometric. The two pencils have identical nose cones, and the barrels and mechanisms are also identical. Only the caps are different. The demi cap is 52 mm from lip to tip of jewel and the standard cap is 57 mm from lip to tip of jewel.

 

I hope this helps.

 

John

[Bill Nick]

A demi and a full size.

 

 

 

IMG_20190526_212124.jpg

 

The full size one in your pic also has a longer cone.

[Bill Nick]

 

I bought some of these pencils. The erasers are a little too big for the ferrule in my P51 pencil. But a minute or two of rubbing the eraser down on a rough piece of paper narrowed the diameter so now it fits perfectly. Thanks for the tip - David

 

How long are those BIC rubbers when you've pulled them out?