tab_width does not work!

[romberli]

tab_width does not work!
i set this parameter to 48,but the tab width is still large.
here is my user settings:
{ "auto_find_in_selection": true, "bold_folder_labels": true, "color_scheme": "Packages/Theme - Brogrammer/brogrammer.tmTheme", "default_line_ending": "unix", "font_size": 15, "highlight_line": true, "highlight_modified_tabs": true, "ignored_packages": [ "Vintage" ], "open_files_in_new_window": false, "show_encoding": true, "tab_overlap": 1, "tab_width": 48, "theme": "Brogrammer.sublime-theme" }