As we all know, the wear resistance of the internal thread formed by aluminum and its alloys is very poor, almost a few times after bolt dismounting is polished, thereby causing slip, cause the entire matrix scrap. However, due to the excellent heat dissipation and electrical conductivity of aluminum and its alloys, and the high strength of the small proportion of small, in many cases can not be replaced with other materials, such as automotive engines, aircraft engines, radiators, etc..
Is there a good way to use aluminum and its alloy material to overcome the internal threads that are formed by it? Yes！ That is in aluminum and its alloy into steel wire screw sleeve.
(Wire Thread Insert steel screw), also known as the thread, thread, thread sheath braces, referred to as wire sleeve and the screw sleeve, is a new type of internal thread fasteners. The utility model is a spiral coil with spring shape which is precisely formed by the cold rolling Diamond Stainless steel wire with high strength, high precision and smooth surface. The utility model is especially suitable for the inner threads formed of soft materials such as aluminum and the alloy thereof to improve wear resistance. Formed by the set of spiral steel wire metric (M) internal thread accuracy is usually 6H, precision is high up to 4H, the American unified thread (UN) the accuracy of 2B or 3B.
The diameter of steel wire Lo sets free state than its desire into the special steel screw thread bottom hole diameter, when assembling the wire Lo sets after installation wrench screw thread guiding ring torsion, making it smaller in diameter screw thread bottom hole in special steel screw. After installation of steel wire Lo sets generated around the expansion effect, which is fixed on the screw thread bottom hole, forming a reliable standard thread, not with the bolt screwing in the rotation and rotation.
The specific use of the method is as follows:
Selection of appropriate drill diameter (according to the specifications of thread steel screw manufacturers will provide specific hole size for you) drilling, drilling depth (greater than or equal to the blind holes) (by Kong Shi) and aluminum alloy matrix for installation of steel wire Lo sets of threaded hole depth; be careful not to drill into cone, should not use serious wear bit, chip falling may cause damage to the. Countersinking drill allows deburring properties, countersinking should not exceed 0.4P depth, steel screw thread installation diameter of large diameter, angle is 120 degrees - 2 degrees.
Using the labeled thread specifications of precission design regulations (ST taps) tapping, tapping the length should be greater than the length of the installation of steel wire Lo sets, for through hole, require all tapping; tapping accuracy determines the final standard internal thread hole tolerance zone, the user to appropriately select tapping method and lubrication. After finishing the thread, thread holes must be cleaned. For some important products, must use a dedicated plug screw sleeve with internal thread precision inspection.
The steel wire screw sleeve can be coated with a small amount of oil or not coated with any material before being screwed into aluminum and its alloy substrate.
Installation of steel wire screw sleeve usually adopts sleeve type manual installation wrench installation (large quantity can choose electric or steam wrench), the specific operation process is as follows:
The first step from the socket wrench mandrel, the wire thread insert from the sleeve slots (slot upward) placed in the sleeve.
With a finger to prevent steel screw move second step, inserted into the core shaft, and the rotating spindle spindle until the notch is stuck installation handle wire Lo sets of (in the case of type T, can be directly used without rotation of the core shaft groove for installing the front end of the wrench handle is stuck installation of steel wire Lo sets).