Self incrimination has never applied to physical evidence that the individual has in his possession, it only applies to things that are "testimonial" (quotes because this is a term of art). After all, the 5A specifically talks about being a witness against one's self, not about providing evidence. See also Fisher v. United States, 425 U.S. 391 (1976), Schmerber v. California, 384 U.S. 757 (1966) and United States v. Wade, 388 U.S. 218 (1967).
The classic example is business or tax records related to fraud prosecutions. An individual served with a valid order cannot refuse to turn over documents because they would tend to incriminate him, that doesn't make sense. You can't force the individual to testify to anything, but you can compel them to produce physical objects that you have probable cause to believe are evidence relevant to the prosecution of a crime.
Another canonical example is a court order forcing an individual to provide a cheek swab for a DNA test. Again, not testimonial because it's not communicative in any way -- you are just talking about physical, tangible evidence.