BS 919-3:1968

Cooperating organizations
Foreword
Specification
1. Scope
2. Nomenclature
3. Function and method of use of the various types
     of gauges
4. Inspection procedures and the settlement of
     disputes
5. Reference temperatures
6. General design features and tolerances of gauges
7. Marking
Tables
1. Dimensions of root clearances of GO screw gauges
2. Dimensions of root clearances of NOT GO screw
     gauges
3. Flank angle tolerances
4. Pitch tolerances
5. External product thread. Deviations for simple
     pitch (effective) diameters of GO screw limit
     gauges and their associated check plugs and
     setting plugs
6. External product thread. Deviations for simple
     pitch (effective) diameters of NOT GO screw limit
     gauges and their associated check plugs and setting
     plugs
7. Internal product thread. Deviations and allowable
     wear for simple pitch (effective) diameters of GO
     and NOT GO screw plug limit gauges
8. Deviations for major diameters of screw check plugs
     and setting plugs for GO screw ring and calliper
     gauges
10. Deviations for major diameters of screw check
     plugs and setting plugs for NOT GO screw ring and
     calliper gauges
11. External product thread. Deviations and allowable
     wear for GO and NOT GO plain calliper and ring
     gauges
12. Internal product thread. Deviations and allowable
     wear for GO and NOT GO plain plug gauges
13. External product thread. Information for
     calculation of limits for new solid GO screw ring
     gauges and their associated check plugs
14. External product thread. Information for
     calculation of limits for adjustable GO screw ring
     and caliper gauges and their associated setting
     plugs
15. External product thread. Information for
     calculation of limits for new solid NOT GO screw
     ring gauges and their associated check plugs
16. External product thread. Information for
     calculation of limits for adjustable NOT GO screw
     ring and calliper gauges and their associated
     setting plugs
17. Internal product thread. Information for
     calculation of limits for GO and NOT GO screw
     plug gauges
Figures
1. 'Blunt start' at end of thread on gauge
2. Screw plug and ring or calliper threads having
     complete flanks
3. Screw plug and ring or calliper threads of
     truncated form
4. Alternative form of GO calliper gauge anvil for
     product threads having pitches finer than 0.5 mm
5. Alternative form of NOT GO calliper gauge anvil
     for product threads having pitches finer than
     1.0 mm
6 & 7. Simple pitch (effective) diameter tolerance
       zones of gauges for external product threads
8 & 9. Simple pitch (effective) diameter tolerance
       zones of gauges for internal product threads

Gives the recommended gauging system for checking ISO metric screw threads of nominal diameters 1 mm and larger been made in accordance with BS 3643. Provision is made for following types of gauges: screw gauges, plain gauges, setting plugs, check plugs, and wear check plugs. Includes information functions and methods of use of the various types of gauges and a recommended method if given for settlement of disputes regarding borderline products. General design features of gauges are described and recommended tolerances on gauges are given: method of calculating manufacturing limits is outlined.