T-slots are provided on most mill tables for fixturing work and workholding devices. These slots are designed to work with T-nuts and are made to either ANSI or ISO standards. See ANSI B5.1M or ISO 299. T-slots can be made to tolerances suitable for holding only to tighter tolerances intended for locating.

T-slots work with T-nuts to fixture work and workholding devices to the table.


T-nuts are designed to work inside of T-slots. ANSI/ASME B5.1M defines T-slot size limits. See Also ISO R286.

Rotary T-nuts are available that can be inserted from the top of the table instead of at the end.

T-nuts are designed to work inside of T-slots.
T-nut being used with a stud and flange nut to attach a vise to a mill table.