# For a tangent ogive, given a radius, can you determine it's length?

A tangent ogive body has a specific radius for a given length, so how would you determine length if only given the radius?

• Assuming you also know the shank diameter... Nov 12 '19 at 16:06

Looking at the the image below:

$$L=\sqrt{r^2-x^2}$$

$$x=r-\left(\frac{D}{2}\right)$$

$$L=\sqrt{r^2-\left(r-\left(\frac{D}{2}\right)\right)^2}=\frac{1}{2}\sqrt{-D (D - 4 r)}$$

• Also, can you determine the length without knowing the ogive radius, but just the shank diameter? I don't think so. But do let me know. Nov 12 '19 at 21:01
• If you know any two of the three (Shank Diameter, Ogive Radius, Length) you can calculate the third value. If you only have one value then you can work out the relationship between the final two, but won’t be able get a fixed value. Nov 13 '19 at 8:54