It is important to note that, silk is permitted for women based on the hadith of ‘Ali ibn Abi Taalib (may Allaah be pleased with him), who said that the Prophet (peace and blessings of Allaah be upon him) took a piece of silk in his right hand and a piece of gold in his left, held them aloft and said: “These are haraam for the males of my ummah and permitted for the females.” (Reported by Ibn Maajah, 2/1189).

Silk is prohibited for men with certain criteria.

Please refer to: http://islamqa.com/en/ref/2037/silk

Following is a part of the answer relevant to this hadith:

The scholars also allowed men to wear garments containing four fingers’ width of silk, because of the hadeeth of ‘Umar ibn al-Khattaab (may Allaah be pleased with him) who said that the Prophet (peace and blessings of Allaah be upon him) forbade the wearing of silk except for an area the width of two fingers, or three or four.” (Reported by Muslim, 3/1644).

With regard to the matters mentioned in the question, the issue is not what a thing is called but what it really is. If the item that a man is going to wear is made of natural silk, then it is not permissible for him to wear it, no matter how it looks or feels, and no matter whether it is a shirt, pants, socks, a necktie or anything else. And Allaah knows best.