ALUMINUM PRECISION PRODUCTS, INC.
November 14,1997
Bill Miller
Bill Miller Engineering
4895 Convair Drive
Carson City, Nevada 89706
Dear Mr. Miller:
Aluminum Precision Products recently received a connecting rod sample machined
from billet. We were asked to pull tensile specimens to check mechanical
properties and to provide a chemical analysis of the metal to determine the alloy.
We were able to pull (2) specimens from the beam area of the rod (one ea. long. and
trans). In addition to the billet rod, APP checked mechanical properties on one of
your forged connecting rods (BME500) for comparison. Both rods were sent to an
independent testing lab for evaluation. The results are as follows:
| Specimen No. |
Rod Type |
Tensile |
Yield |
Elong. |
Hardness |
Comments |
| 1-Long. |
Forged |
98.6 KSI |
91.5 KSI |
12.5% |
92.0/HRB |
|
| 1-Trans. |
Forged |
89.8 KSI |
82.7 KSI |
10.0% |
|
|
| 2-Long. |
Billet |
69.2 KSI |
60.0 KSI |
14.0% |
76.0/HRB |
7075 alloy |
| 2-Trans. |
Billet |
69.3 KSI |
59.6 KSI |
15.0% |
|
|
We are very surprised with these results as the billet rod does not even meet 7075-T6
minimum properties. In comparison, the material we are using for your forged
rods have mechanical properties that are over 45% higher than the billet rods.
Based on the above data, the raw forgings APP supplies to BME have superior
strength to that of billet rods. It appears that the manufacturer of the sample billet
rod we received is supplying an inferior product to the racing industry.
Walter E. Howard
3333 W. Warner Ave., Santa Ana, California 92704 [714] 546-8125 Fax [714] 540-8662
| 
