What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
GBT 3098.19-2004 blind rivets in my country are divided into: GB/T12615 closed oblate head blind rivets; GB/T12616 closed countersunk head blind rivets; GB/T 12617 open type countersunk head blind rivets; T 12618 Open-type oblate head blind rivets; the international standard is DIN7337; there are 1990 versions and 2004. The 2006 version is mainly the 2006 version.
T-slot bolts refer to the bolts installed in the T-slot. The installation process of T-slot bolts is usually as follows. When the T-slot (generally refers to the T-slot aluminum alloy profile) is set horizontally, the bolt The bolt head is placed in the T-slot in the horizontal direction, the bolt shaft is facing outward, and then the bolt is rotated 90 degrees axially, the bolt head becomes vertical and will not come out of the T-slot, and then install the mounting hole of the object Align the bolt rod and insert it and screw the nut on the bolt rod. During the tightening process of the nut, if the thread gap is small or the thread is damaged or there is dirt, the bolt will often rotate, and the rotation angle of the bolt is uncontrollable and impossible. Observe that when the rotation angle of the bolt is in the range of about 90 degrees, the bolt is in a state of being released from the T-shaped groove at any time. Even if the nut is tightened, the installation of the installation object is invalid and unreliable, and there is a serious safety hazard. , the actual situation is that when the rotation angle of the bolt exceeds 20-30 degrees, the installation of the installation object is already unreliable.
In order to achieve this purpose, the rivet nut is cold extruded from low carbon steel, the brim is cold forged, the deformed skirt is extruded in the die, and the threaded hole is extruded at the lower end of the deformed skirt. It is characterized in that it consists of a brim, a deformed skirt and a threaded hole. There are fish teeth below the brim; the outer side of the lower end of the threaded hole has a lead angle; the cross section of the thread on the inner wall of the threaded hole is an isosceles trapezoid, and the upper bottom of the trapezoid is a concave arc. Thus, the riveted object is tightly connected with the rivet nut.
In the process of construction of major projects, fasteners are mainly used to connect grooved embedded parts and fixed objects. They are widely used in civil curtain walls, prefabricated buildings, subways, high-speed railways and other industries.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
