Friday, December 23, 2011

Uni .7mm HB Nano-Dia Pencil Lead about 30% stronger than Alvin Draft-Matic




My Mom gave me an Alvin Draft-Matic 0.7mm pencil for Christmas, but I noticed the lead that came with the Alvin pencil did not seem as strong as the lead I have grown accustomed to. The lead that I have been using was in a Uni Kuru-Toga pencil and it was .5 mm "Nano Dia" diamond-infused lead. I acquired some Uni 0.7 mm Nano Dia lead to refill the Alvin Draft/Matic and did some tests.


I tested at 2 mm and 3 mm pencil lead length with each of the types of lead. I used the same pencil for all tests. My goal was to estimate the breaking strength of each type of lead so that I can determine whether one type of lead was stronger than the other.

I held the pencil in a normal writing position, and pressed down on the scale to measure the weight on the scale when the lead broke.

The results were quite consistent. The Uni Nano-Diamond lead was around 30% stronger than the lead that came with the Alvin Draft/Matic.

In particular, at 2 mm, the Uni lead broke at an average 626 grams, while the Alvin lead broke at 438 grams. This yields a 35% strength difference. At 3 mm, the Uni broke at an average 512 grams, while the Alvin broke at an average 384 grams. This shows. 29% strength advantage for the Uni.

I am really not certain what kind of lead Alvin ships with her Draft/Matic pencil. But my experience with the Uni lead has been good so far.

2 comments:

Glynn said...

Ah ha..someone else was curious about the lead to the point they tested what I wanted to know. Thanks for posting this.

I had been looking for self-advancing pencil when I found the Kuri Toga and was hooked on the concept of the lead rotating during use. I love having a constantly sharp line but I think I may have put in a 'foreign' lead at some point. I noticed the difference a few days ago and finally ran out of that one piece...the pencil is awesome and the stronger lead makes for an even better tool.

Chris Heath said...

In their marketing they don't bother showing testing, Saw this in a google search for Uni dia lead. Thanks! SCIENCE!