BS 328-2:1972

Cooperating organizations
Foreword
Specification
1. Scope
2. Manufacturing requirements for combined drills
    and countersinks (centre drills)
3. Dimensions of combined drills and countersinks
    (centre drills)
4. Designation
5. Combined drills and countersinks (centre drills)
    for centre holes without protecting chamfer. Type A
6. Combined drills and countersinks (centre drills)
    for centre holes with protecting chamfer. Type B
7. Combined drills and countersinks (centre drills)
    for centre holes with radius form. Type R
Appendices
A. Recommended dimensions for centre holes. Type A
B. Recommended dimensions for centre holes. Type B
C. Recommended dimensions for centre holes. Type R
Tables
1. Dimensions of combined drills and countersinks
    (centre drills). Type A
2. Dimensions of combined drills and countersinks
    (centre drills). Type B
3. Dimensions of combined drills and countersinks
    (centre drills). Type R
4. Dimensions for centre holes. Type A
5. Dimensions for centre holes. Type B
6. Dimensions for centre holes. Type R
Figures
1. Single-ended combined drills and countersinks
    (centre drills). Type A (d < 0.8 mm)
2. Double-ended combined drills and countersinks
    (centre drills). Type A (d > 1 mm)
3. Combined drills and countersinks (centre drills).
    Type B
4. Combined drills and countersinks (centre drills).
    Type R
5. Type A centre hole
6. Type B centre hole
7. Type R centre hole

Designations and dimensions of combined drills and countersinks (centre drills) for centre holes, without protecting chamfers, with protecting chamfers or of radius form.

Withdrawn:This standard is no longer used