You can also sinter it, it doesn't need to be especially strong, just hold itself together while falling, and sintering can make it strong enough.
The strength plays no part at all when it impacts. At the energy involved it might as well be a noodle. It just needs to handle the heat and resistance of reentry. Mainly heat.
So why tungsten, rather than a tungsten skin on a lead bar?
Also, the density of tungsten is about 75% larger than that of lead. Iridium and osmium are about 15% heavier still, at about twice the density of lead (osmium is heavier, but by only 0.12%)
To hit one target on the ground you are going to need thousands of rods in orbit to ensure that one is available to use on the target. This is necessary because things in orbit will only be able to de-orbit on top of things that are close to their orbital plane.
I was curious about the price of this so I did some monster math (FYI complete arms layman, serious errors are likely).
Raw materials: Volume is 15.7 cu ft = 444,574.5 cm3. Density is 19.3g/cm3 = 8,580 kg. Estimated price of $30.3k per metric ton [1] = $260k in tungsten. Cheap.
Now for launch price. SpaceX advertises $90 million for 8 metric tons launched into low-earth orbit [2]. Yowza.
A single Trident submarine based missile is in the order of $65-$100 million depending on various sources. So cost-wise these seem within the same order of magnitude as nukes.
1: https://www.metalary.com/tungsten-price/ 2: https://spacenews.com/wp-content/uploads/2016/05/spacex-pric...