Main Data
- Description: Rolling mill screw-down screw shaft
- Screw thread type: buttress thread form
- Screw thread pitch: 45 mm
- Starts of threads: 2
- Helical hand: Right
- Accuracy of screw thread:
- Single pitch error shall be less than ±1%
- Accumulated error shall be less than ±5%
- Screw shaft:
- Material of screw shaft: Alloy steel
- Heat treatment: Quenching and carburizing
- Hardness: HS30~35
- Thread surface finish: Turning
- Major diameter: 390 mm
- Pitch diameter: 361 mm
- Minor diameter: 331 mm
- Height of thread: 29.5 mm
- Spline part:
- Tip diameter: 440 mm
- Normal circular thickness: 70 mm
- Whole tooth depth: 60 mm
- Number of teeth: 8
- Length: 1100 mm
- Spline surface finish: Ground
- Nut
- Material: Copper alloy
- Hardness: 100HBS
- Thread surface finish: Milling
- Number of threads: 11
- Out Diameter: 650 mm
- Major diameter: 394 mm
- Pitch diameter: 361 mm
- Minor diameter: 332 mm
- Height of thread: 31 mm
- Length: 590 mm
The Main Fabrication Procedure
- Screw shaft
- Forging the shaft blank
- Normalizing
- Rough turning
- Ultrasonic inspection
- Quenching and tempering
- Semi-finish turning
- Grinding the splines
- Turning threads
- Inspection magnetic inspection the thread flank, and then magnet demagnetization
- Facing up
- Nut
- Centrifugal casting
- Rough turning
- Semi-finish turning
- Milling the threads
- Facing up
Technical Documents
- Inspection certificate of material
- Mechanical property test report
- Heat treatment certificate
- Non-destructive inspection(Certificate of ultrasonic inspection)
- Record of hardness
- Magnetic particle detection certificate(on tooth flank)
- Size tolerance and geometric tolerance report
- Inspection report of thread quality
Application
- Rolling mill screw-down mechanism