• Production Assembly

Production Technology Flow

LDB’slewing bearing strictly enforced in accordance with the process of production and quality standards, each link has a rigorous quality control. 100% inspection of manufactured products, each product has a unique product number, to ensure product traceability.

flow chart

01. Raw Materials

Raw Material
Raw Material2
Raw Material

All our raw materials 50Mn, 42CrMo and 42CrMo4 sourced from Daye Speical Steel Co.,Ltd, Xingcheng Steel; Magang (Group) Holding Co.,Ltd.

02. Raw Material Forging+Normalizing/Quenching and tempering


After Q&T, the forgings’comprehensive mechanical properties could be improved,

03. Rough Turning

Rough turning(1)
Rough turning(1)

After rough turning, boundary dimension must be inspected to ensure dimensions within scope of dimension processing technology.

04. Hardness Test

The hardness of Normalizing range HB187-241.The hardness of Quenching and tempering range HB229-269.

05. Ultrasonic Testing

Ultrasonic testing(1)

Using UT to test if the forgings have inner defect

06.Semi-extractive Turning

Semi-extractive turning

Finish turning and shaping before raceway quenching.

07. Raceway Quenching

Raceway hardened (1)
Raceway hardened (3)
Raceway hardened

08. Raceway Surface Hardness Test

After raceway hardening, LDB Slewing bearing’s raceway surface hardness will range HRC55 -60

09. Raceway Hardening Layern Depth Test

Depth detection of hardened layer

After raceway hardening, Hardened hardness layer depth larger than 3mm.

10. Raceway Fluorescent Magnetic Particle Flaw Detection

The raceway is tested for cracks after quenching

11. Stable and Tempering

Stable and tempering

Release the internal stress, make the material structure more stable

12. Finish Turning

Finish turning

Finish turning after quenching

13. Tooth Maching


Use CNC hobbing machine/gear shaper to make gear according to process requirements

14. Gear Hardening

After gear hardening, its surface hardness will reach to 45-55HRC.

15. Gear Test

Check the size and precision of tooth profile, meet the process requirements

16. Hole Machining


Use machining center or other machine tools for hole machining according to the process to ensure the accuracy of hole position

17. Hole Inspection

Inspection items include: hole diameter,chord length and centeral diameter.

18. Matching Clearance

Matching clearance
Matching clearance

Machining the raceways of two sets of rings with processing, to ensure that the clearance of slewing bearing within the process requirements.

19. Assembly


Workers removing burrs after ferrule overall cleaning. They put in strict accordance with the requirements of the drawings rings, rolling elements, spacers and seals assembled. After checking the appearance of the finished product assembled again until perfect.

20. Inspection for Finished Products


The inspection items include clerance, runout, appearance and rotation flexibity.

21. Mark


The finished slewing bearings need to have factory mark and product Serial No.,our company also supply OEM service and neutral product.

22. Packaging


Standard export packing: Plastic film,kraft paper and nylon wraping belt.Product outer label,Qualified certificate,Assemling & maintenance manual and free funigation plywood case.