I bought some of that crap online and made a small cigar box out of it. That "iron wood" dulled every blade, chisel and bit in my shop. That stuff is incredibly hard.
iron wood.
It sinks in water?
Knife makers use it for handles.
The Janka Hardness Scale ratings:
Popular 300
Black Cherry 950
Burmese Teak 1050
Red Oak 1290
White Oak 1360
Hickory(the hardest North American Species) 1850
Brazilian Cherry(Jatoba) 2850
African Ebony 3250
Cumaru 3540
IPE 3600
This means that IPE is roughly twice as dense(hard) as Hickory and three times as hard as Red Oak. IPE and Cumaru are very difficult to work with, even with carbide tipped blades and pneumatic equipment. I distinctly remember breaking off Stainless Steel deck screws even after predrilling the holes when I last worked with IPE. The next time I used PVC.