Already a subscriber?
MADCAD.com Free Trial
Sign up for a 3 day free trial to explore the MADCAD.com interface, PLUS access the
2009 International Building Code to see how it all works.
If you like to setup a quick demo, let us know at support@madcad.com
or +1 800.798.9296 and we will be happy to schedule a webinar for you.
Security check
Please login to your personal account to use this feature.
Please login to your authorized staff account to use this feature.
Are you sure you want to empty the cart?
BS 93:2008 British Association (B.A.) screw threads. Requirements, 2008
- Contents [Go to Page]
- 1 Scope 1
- 2 Normative references 1
- 3 Terms and definitions and symbols 1
- 4 Profile of British Association (B.A.) screw thread 2
- 5 Basic sizes of B.A. threads 3
- 6 Tolerance classes and limits of sizes, and tolerances, for B.A. threads 3
- 7 Gauges 4
- Annexes
- Annex A (informative) Basis of sizes of B.A. threads 12
- Annex B (informative) Bases of allowances and tolerances for B.A. threads 12
- Annex C (informative) Effect of errors in pitch and flank angle on the effective diameter 14
- Annex D (informative) Approximate inch equivalents of B.A. thread sizes 16
- Bibliography 21
- List of figures
- Figure 1 - Basic form of B.A. thread 2
- Figure 2 - Tolerance zones for a close class external thread and an internal thread 5
- Figure 3 - Tolerance zones for a normal class external thread and an internal thread 5
- Figure 4 - Example of effective diameter tolerance zones (Effective diameter tolerance zones for size 2 B.A. threads illustrated) 6
- List of tables
- Table 1 - Basic sizes of British Association (B.A.) screw threads 7
- Table 2 - Limits and tolerances for close class external threads - Sizes 0 B.A. to 10 B.A. 8
- Table 3 - Limits and tolerances for normal class external threads - Sizes 0 B.A. to 10 B.A. 9
- Table 4 - Limits and tolerances for normal class external threads - Sizes 11 B.A. to 16 B.A. 10
- Table 5 - Limits and tolerances for internal threads - Sizes 0 B.A. to 16 B.A. 11
- Table B.1 - Summary of tolerance formulae 13
- Table D.1 - Basic sizes of British Association (B.A.) screw threads - Approximate inch equivalents 16
- Table D.2 - Limits and tolerances for close class external threads - Sizes 0 B.A. to 10 B.A. - Approximate inch equivalents 17
- Table D.3 - Limits and tolerances for normal class external threads - Sizes 0 B.A. to 10 B.A. - Approximate inch equivalents 18
- Table D.4 - Limits and tolerances for normal class external threads - Sizes 11 B.A. to 16 B.A. - Approximate inch equivalents 19
- Table D.5 - Limits and tolerances for internal threads - Sizes 0 B.A. to 16 B.A. - Approximate inch equivalents 20
- Foreword
- 1 Scope [Go to Page]
- a) basic sizes for B.A. threads, sizes 0 B.A. to 16 B.A.;
- b) limits of size, and tolerances, for close class and normal class external threads of sizes 0 B.A. to 10 B.A.;
- c) limits of size, and tolerances, for normal class external threads of sizes 11 B.A. to 16 B.A.;
- d) limits of size, and tolerances, for a single class of internal threads of sizes 0 B.A. to 16 B.A.
- 2 Normative references
- 3 Terms and definitions and symbols [Go to Page]
- 3.1 Terms and definitions
- 3.2 Symbols
- 4 Profile of British Association (B.A.) screw thread [Go to Page]
- Figure 1 Basic form of B.A. thread
- 5 Basic sizes of B.A. threads
- 6 Tolerance classes and limits of sizes, and tolerances, for B.A. threads [Go to Page]
- a) Close class external threads. Limits and tolerances for close class external threads of sizes 0 B.A. to 10 B.A. shall be as specified in Table 2.
- b) Normal class external threads. Limits and tolerances for normal class external threads of sizes 0 B.A. to 10 B.A. shall be as...
- 7 Gauges [Go to Page]
- Figure 2 Tolerance zones for a close class external thread and an internal thread
- Figure 3 Tolerance zones for a normal class external thread and an internal thread
- Figure 4 Example of effective diameter tolerance zones (Effective diameter tolerance zones for size 2 B.A. threads illustrated) [Go to Page]
- Table 1 Basic sizes of British Association (B.A.) screw threads
- Table 2 Limits and tolerances for close class external threads - Sizes 0 B.A. to 10 B.A.
- Table 3 Limits and tolerances for normal class external threads - Sizes 0 B.A. to 10 B.A.
- Table 4 Limits and tolerances for normal class external threads - Sizes 11 B.A. to 16 B.A.
- Table 5 Limits and tolerances for internal threads - Sizes 0 B.A. to 16 B.A.
- Annex A (informative) Basis of sizes of B.A. threads
- Annex B (informative) Bases of allowances and tolerances for B.A. threads [Go to Page]
- B.1 Allowances
- B.2 Tolerances
- B.3 Tolerances on effective diameters [Go to Page]
- B.3.1 External threads
- B.3.2 Internal threads
- B.4 Tolerances on major diameters [Go to Page]
- B.4.1 External threads
- B.4.2 Internal threads
- B.5 Tolerances on minor diameters [Go to Page]
- B.5.1 External threads
- B.5.2 Internal threads [Go to Page]
- Table B.1 Summary of tolerance formulae
- Annex C (informative) Effect of errors in pitch and flank angle on the effective diameter [Go to Page]
- C.1 Effect of pitch errors
- C.2 Effect of errors in flank angle
- C.3 Criteria for acceptability of a combination of errors in the effective diameter, pitch and flank angle of a screw thread [Go to Page]
- a) External threads. To be acceptable, the simple effective diameter of an external thread (as measured along the pitch line of ...
- b) Internal threads. To be acceptable, the simple effective diameter of an internal thread (as measured along the pitch line of ...
- Annex D (informative) Approximate inch equivalents of B.A. thread sizes [Go to Page]
- Table D.1 Basic sizes of British Association (B.A.) screw threads - Approximate inch equivalents
- Table D.2 Limits and tolerances for close class external threads - Sizes 0 B.A. to 10 B.A. - Approximate inch equivalents
- Table D.3 Limits and tolerances for normal class external threads - Sizes 0 B.A. to 10 B.A. - Approximate inch equivalents
- Table D.4 Limits and tolerances for normal class external threads - Sizes 11 B.A. to 16 B.A. - Approximate inch equivalents
- Table D.5 Limits and tolerances for internal threads - Sizes 0 B.A. to 16 B.A. - Approximate inch equivalents
- Bibliography [Go to Page]