This kind of hard gray-black oxide scale is mainly composed of NiCr2O4 and NiF, two EO4 components. There are two main methods for the treatment of oxide scale in stainless steel screw factories: Sandblasting method: mainly adopts the method of spraying micro glass beads to remove the black oxide scale on the surface.

Use the drill bit installed on the percussion rig to drill holes, drill through the auxiliary parts, and drill into the basic parts. This device can be used in most solid wall mounts that require quick fixation of metal or wooden accessories (maximum thickness of 100 mm). Aluminum pull stud is a kind of fastener between drilling fastener and base deformation fastener.

Screw manufacturers should pay attention to the following two points when installing aluminum pull studs: When installing aluminum rivets, the accuracy of the pre-drilled holes is critical to the performance of this type of fastener. It can drill holes through the auxiliary parts, so that the fixing can be completed by one-time operation. After the auxiliary parts are installed, they can be used if necessary.

It requires drilling a highly precise mounting hole whose diameter is slightly smaller Sheet Metal Screws than the thread diameter of a screw made of hardened steel. The depth of the drill hole in the base must be at least 6 mm greater than the embedded depth of the screw (the minimum embedded depth is 25 mm, and the maximum is 37 mm). The type of aluminum pull stud head is flat head type with cross recess or hexagonal washer type. Its function is like a clutch, which can make the drill bit and the auxiliary part out of contact.

They can be slotted in large-volume wooden structures. The fixing device of aluminum pull studs includes aluminum screws, a tool for screwing screws installed on a drilling rig, and a specially manufactured carbide drill bit.