Screw Bolts, Screw Spikes and Anchor Bolts and Nuts Factory
24*195 double head screws are used for Type I, II, III railway fastening systems with rail clips.
Anchor bolts in the railway construction are used to fix the track fastening systems with other rail fasteners to fix the steel rails, the anchor bolts are inserted into the concrete base to hold the rail in place, and the top portion of the anchor bolt is embedded in the concrete base.
1. Raw materials
The raw material of the screw spike is Q235-A in accordance with GB/T 700 or other materials whose performance is not lower than that.
2. Size
a) The upper thread of the screw spike is M24, the basic dimensions should comply with GB/T 196, and the thread tolerance is made according to the 8g specified in GB/T 197-2003.
b) The lower thread of the screw spike is a special M25.6X6 – thread.
c) The end of the screw spike is as specified in GB/T 2.
3. Appearance
a) Forged burst cracks on the truncated surface of the screw spike shall not extend to the shaft.
b) The upper thread of the screw spike shall not have defects such as bumps, burrs, and scratches that affect the use.
c) The lower thread of the screw spike should have a neat tooth shape and complete thread, and there should be no splitting marks.
d) There should be no dents, burrs, burrs, burns, and oxide scales on the surface of the screw spikes.
4. Tensile properties
Screw spikes shall not break after being subjected to a tensile force of 130 kN.
5. Cold bending performance
Screw spike by 45#. After cold bending, it should not be broken, and the depth of cracks (except road stud round table) is not more than 1.0 mm, and the anti-rust layer and the superficial layer of the substrate are allowed to have slight peeling, wrinkles, and cracks.
6 Anti-rust properties and signs
The anti-rust performance and marking of screw spikes shall meet the following requirements:
a) Screwspikes after anti-rust treatment shall meet the dimensional accuracy and performance requirements. Different signs and colors should distinguish the screw spikes used in different regions.
b) The anti-rust performance requirements and marks of the screw spikes are shown in the table.
Anti-rust performance requirements and marking of screw spikes
| Application | Anti-rust performance requirements | Mark |
| General area or coastal area | After the screw spike is sandblasted, the protection level shall not be lower than level 5 after 120 hours of neutral salt spray test. | 1 |
| Areas with severe acid rain corrosion | 1) After the 120 h sulfur dioxide test, the protection level of the screw spike should not be lower than level 5;
2) After the screw spike is sandblasted, the protection level shall not be lower than level 5 after 48 hours of sulfur dioxide test. |
2 |
| Acid rain corroded coastal areas | 1) After the screw spike is sandblasted, the protection level shall not be lower than level 5 after 120 hours of neutral salt spray test;
2) After the 120 h sulfur dioxide test, the protection level of the screw spike shall not be lower than level 5; 3) After the screw spike is sandblasted, the protection level should not be lower than level 5 after 48 hours of sulfur dioxide test. |
3 |
