WE CLAIM:
Claim 1. A nut (10) comprising a plurality of plate-shaped members (12) having through holes (16) whose diameters are substantially same; wherein:
each of the plate-shaped members (12) has a plurality of screw threads (18, 38) arranged at predetermined angular intervals, the screw threads protruding inward of the through hole (16); and
the plate-shaped members (12) are laminated so that the through holes (16) are substantially coaxial with each other.
Claim 2. The nut (10) according to claim 1, wherein: the screw threads (18, 38) are screw threads of a
multi-start thread; and
in each of the plate-shaped members (12), spaces (20)
are formed between the screw threads (18, 38) so that the
screw threads (18, 38) do not mutually overlap in an axial
direction of the nut (10).
Claim 3. The nut (10) according to claim 1 or 2, wherein:
a thickness (L) of each of the plate-shaped members (12) is equal to or less than a thread pith (P) of each of the screw threads (18, 38).
Claim 4. The nut (10) according to any one of claims 1 to 3, wherein:
the plate-shaped members (12) are joined together.

Claim 5. The nut (10) according to claim 4, wherein: outer peripheral portions of the plate-shaped members (12) are joined together in a state that the plate-shaped members (12) are laminated so that screw threads (18, 38) of the plate-shaped members (12) are continuously connected in an axial direction of the nut (10).
Claim 6. The nut (10) according to claim 4 or 5, wherein:
the plate-shaped members (12) are joined together in a state that a jig (28, 52) with a male thread (27) formed thereon is screw-engaged with the screw threads (18, 38).
Claim 7. The nut (10) according to claim 6, wherein: the plate-shaped members (12) are laminated without any gap on the jig (28, 52) in the axial direction by the screw threads (18, 38) being screw-engaged with the male thread (27).
Claim 8. The nut (10) according to claim 7, wherein: in order that a backlash (b) formed between the nut (10) and a screw shaft (52) of an object (50) when the nut (10) is screw-engaged with the screw shaft (52) is adjusted to a predetermined backlash (b) in accordance with specifications of the object (50), the screw threads (18, 38) are screw-engaged with a male thread (27) of one jig (28) of a plurality of the jigs (28) and the plate-shaped members (12) are laminated without any gap relative to the one jig (28).

Claim 9. The nut (10) according to any one of claims 4 to 8, wherein:
the plate-shaped members (12) are joined together by welding.