Helicoil insert (sometimes written as Heli coil insert), also known as helicoil thread sleeve, is a new type of internal thread fastener, which is developed to protect non-ferrous metal threaded hole, and is suitable for threaded connection. Its structure is a kind of spring-shaped concentric body of internal and external threads made of stainless steel wire with high-precision rhombic cross-section. Helicoil is the first brand in the steel wire insert industry. It is originated in the United States. It has absolutely reliable quality. It provides a reliable thread repair solution for the industrial field. It is the only thread sheath brand recognized by NASA. Helicoil screw sleeve products enjoy high reputation in the fields of aviation, military industry, automobile, electronic communication and medical treatment.

Helicoil features:

1. Good corrosion resistance.

2. Heat resistance and wear resistance.

3. Uniform load and distributed stress.

4. Simple and fast detection of leakage.

5. Diversified product specifications.

6. Comprehensive supporting tools and installation system.

Helicoil insert application:

Helicoil inserts are mainly used for thread reinforcement and repair, which can provide high strength, heat-resistant and wear-resistant high-precision threads for your needs. Internal thread is often damaged due to various reasons, such as smooth wire, random thread, wear, corrosion, rust, etc. Sometimes the damage of internal thread will cause serious loss, the light one will affect the assembly process and assembly quality, and the heavy one can cause the whole large piece to be scrapped. In the field of thread reinforcement and repair, helicoil insert is considered to be the most reliable solution. After installing helicoil thread sheath, the repaired thread is the same as or even better than the new one, especially for parts with low strength, such as aluminum alloy, copper alloy and plastic parts. In addition, the use of Heli coil thread sheath in the design of parts can help to reduce the space occupied by the original parts and reduce the use of general materials, so as to reduce the weight of parts.

Helicoil insert specification:

Helicoil thread sheath thread specification: according to the thread specification, helioil screw sleeve can be divided into metric system (coarse thread and fine thread), unified coarse thread screw sleeve (UNCC) and unified fine thread screw sleeve (UNF). In addition, there are British Standard (coarse thread BSW and fine thread BSF) and pipe thread (g) specification thread sheath.

Length specification of helicoil thread sheath: generally, the length of screw sleeve is selected according to the multiple of nominal diameter D of the bolt installed in it. Each kind of screw sleeve has 1D, 1.5D, 2D, 2.5D and 3D length. For example: M6, 1.5D long screw sleeve can form an internal thread hole with length of 9mm after installation.

Helicoil inserts classification:

According to its own structure, helicoil inserts can be divided into two types: free running and screw lock. The locking type screw sleeve can clamp the bolts installed in it through one or more circles of polygonal coils in the middle of the screw sleeve to prevent loosening. Additional locking gaskets are not necessary, which can reduce costs and ensure simplified assembly.

Helicoil insert application:

Enhance the connection strength: screw it into metal or nonmetal material to form high strength standard internal thread. The application in low strength engineering materials such as aluminum, copper, magnesium alloy and plastics can obviously improve the connection strength and wear resistance of the thread.

Maintenance: in case of thread processing error or repair of damaged internal thread hole, screw sleeve can be used as repair method, which can be repaired economically and conveniently, and the original specification screw is still used.

Conversion of different thread specifications: screw sleeve is used to convert the screw holes of metric system ←→ British system ←→ unified thread.

About 80% of helicoil inserts are used in military and aviation industries to provide high strength internal threads. There are 304 stainless steel, titanium alloy, phosphor bronze, Inconel x750 alloy, nitronic60, nickel alloy, special coating, such as no coating, dry lubricant coating (molybdenum disulfide), cadmium plating, primer freetm, silver plating, etc. Among them, a Boeing 747 needs 250000 inserts, and an average space shuttle also needs 250000 inserts to tighten the threads.

Heli coil insert standard:

1. The chemical composition and physical properties meet as7245, ASME sa-497, as7246 standards.

2. It meets military standards ms21208, nasm21209, nasm22076 to nasm12275, nasm124651 to nasm124850, ms9018 and military specifications nasm8846.

3. Meet the aviation standards ma3279, ma3280, ma3281, ma3329, ma3330, ma3331, ma1565.

4. It conforms to iso9001-iso / TS 16949 standard.