PURPOSE: To make the combination of a spike main body and the backing seat strong and sure by fitting a spike main body to the backing seat blank of bottomed cylindrical shape and by deforming to the outer part and inner part the compressed wall with the compression in the axial direction.

CONSTITUTION: The blank 4 of a backing seat is formed in the bottomed cylindrical body having the recessed part 5 to hold with engagement the flange part 3 of the spike main body 1 by forming with rolling a metallic material. The rolling is performed by fitting the spike main body 1 to the recessed part 5 thereof and by arranging a punch 11 between the space with a die 12. A discoid seat part 9 is formed with the compressed deformation in the axial direction by a pressing part 14 and by extruding the compressed wall to the outer part in radial direction and simultaneously the release end part of the blank 4 is pushed into the forming recessed part 17 of the die 12 to hold the bottom part of the flange part 3. Further with the descent of the punch 11 the holding part 8 to fix the flange part 3 with its holding is formed and the backing seat 10 composed of the holding part 8 and seat part 9 connected to the outer periphery thereof is formed and simultaneously the spike main body 1 and backing seat 10 are combined via the holding part 8.