Threaded holes formed in hollow profiles, esp. in square pipes - where row of tubular holes surrounded by recesses is pressed by punches and die into profile

摘要

Tool set includes a die formed by a wedged-shaped mandrel placed in the bore of the profile and held against the inner surface of the profile by a second wedge. Mandrel has a row of counterbored die holes, each of which is aligned below a small dia. guide hole in the profile. Above the profile is a holding down plate contg. a row of holes; eac hole contains a stamping punch contg. a coaxial drawing punch as described in abstract 2907415. All the punches are mounted on a common press ram, so a row of tubular holes can be formed in one operation; and round each hole is a ring groove used to deform a washer and thus make a seal.