DIN8140 MS21209 Type Stainless Steel Wire Thread Insert For Metal

Construction

The wire thread insert is made of high-hardness, corrosion-resistant steel wire with a diamond-shaped cross-section. It is a spring-shaped concentric body of internal and external threads. The standard internal thread used for fastening parts has a cross-sectional shape that is a combination of two internal and external threads. Wire thread inserts are divided into two types: ordinary type and locking type, each with or without breaking grooves and with breaking grooves.

The locking type is a polygonal locking ring with one or more turns on the basis of the ordinary screw sleeve. The elasticity of the locking ring has a braking effect on the screw. The locking wire thread insert has all the advantages of the ordinary wire thread insert, does not affect the installation of the screw, and only increases the appropriate torque during installation.

Performance

1. Wire thread inserts are used in various low-strength materials, which can greatly improve the wear resistance of screw connections and avoid damage to the connecting threads.

2. Due to the certain elasticity of the wire thread insert, the load distribution on each circle of the thread can be more uniform, eliminate the pitch and tooth form deviation between the screw and the screw hole, and can absorb vibration, thus improving the connection strength and resistance of the thread. Fatigue strength.

3. The locking wire thread insert can lock the screw in the threaded hole, so that the screw will not loosen when it is subjected to shock and vibration, and the process performance is better than that of the usual locking device.

4. Compared with the method of inserting steel or copper bushings, under the same strength conditions, screws with smaller size and higher strength can be selected, which can reduce the volume and reduce the weight.

5. The hardness of the wire thread insert is higher than that of the screw, so it is less abraded in the process of connecting and disassembling with the screw, and can be used repeatedly.

Specification notation:

1. According to the marking method of domestically produced wire thread inserts:

(1) ST (ordinary type) STd (diameter) p (pitch)-nd

(2) ZST (locking type) ZSTd (diameter) p (pitch)-nd

(3) ZGST (high temperature locking type) ZGSTd (diameter) p (pitch)-nd

2. According to the marking method of foreign production wire thread inserts:

(1) FR (common type) MD (diameter) × P (pitch)-nD (diameter)

(2) SL (locking type) MD (diameter) × P (pitch)-nD (diameter)

Standard notation

D (diameter) × P (pitch) × N or W (number of turns of wire thread insert in free state)

Note: Each domestic standard for wire thread inserts has specific regulations on the marking method of wire thread inserts, please refer to each standard for details