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.