BS 1498:1954

Cooperating organizations
Foreword
Specification
Section one: Scope
1. Scope
Section two: Materials, Design and General Construction
2. Materials and workmanship
3. Design
4. Access to lower journal
5. Lubrication
Section three: Inspection and Testing
A. Conditions of inspection and testing
6. Gauging and inspection instruments
7. Methods and facilities for inspection and testing
8. Standard reference temperature
9. Load on machine
B. Tests on Machine after erection
10. Place of testing
11. Temperature control
12. Cutting tests
13. Test blanks
Section four: Feed screws
14. Definition
15. Manufacture
16. Rigidity
17. Cumulative pitch errors
18. Cyclic error
18a. Feed screw assembly
Section five: Hob saddle motion
19. Cumulative error
20. Cyclic error
21. Parallelism of the hob saddle motion to the axis
     of rotation of the table or work spindle
Section six: Hob spindle and hob arbor
22. Eccentricity of rotation of the hob spindle and
     hob arbor
23. Eccentricity of hob arbor support relative to
     axis of hob spindle
24. Axial float of the hob spindle
25. Diameter of hob arbor
Section seven: Main indexing worm and worm assembly
26. Reference surfaces
27. Adjacent pitch error in main indexing worm
28. Cumulative pitch error in main indexing worm
29. Cyclic error in main indexing worm
30. Accuracy of worm assembly
Section eight: Master wheels
31. Transverse pitch errors
32. Reference band on master wheel
Section nine: Table motion
33. Cyclic error in table motion per revolution of
     worm shaft, per revolution of hob spindle and at
     any other frequency
34. Periodic error in table motion in creep machines
     at master wheel tooth contact frequency
35. Permissible resultant pitch error in worm wheel/
     creep wheel combination of creep table machines
36. Reference band on work table or face plate
37. Axial movement of the table or face plate
Section ten: Intermediate gears
38. Errors in gears between the hob spindle and table
     worm shaft and those driving the feed screw
Section eleven: Test gears
39. Transverse pitch errors
40. Undulations
41. Axial pitch error
Appendices
A. Stress-relief annealing of iron castings
B. Heat treatment of feed screws
C. Approximate metric equivalents
D. Matching of cumulative pitch errors

Design and required accuracy limits of machines, with or without creep gear, for production of high grade gears for turbines and similar drives. Grade A for heavy loads and high speeds, grade B for normal loads and speeds. Accuracy limits also for: feed screw, main indexing worm, worm assembly, master wheel and other features. General procedure for accuracy determinations.