BS AU 50-2.3:1994

Foreword
Committees responsible
Specification
3.1 Scope
3.2 References
3.3 Definitions
3.4 Information and requirements to be agreed and to
      be documented
3.5 Surface condition
3.6 Captive washers for spigot-type wheel-nuts
3.7 Materials
3.8 Forming of bolts and studs
3.9 Coatings and surface treatments
3.10 Thread form and quality
3.11 Dimensions
3.12 Testing
3.13 Disposal of tested components
3.14 Performance
3.15 Documentation
3.16 Marking and identification
Annexes
A. (normative) Dimensions of DIN spherical-faced
      (spherical collar) nuts (type A)
B. (normative) Quality
C. (normative) Proof test for flat-faced nuts
D. (normative) Proof test for conical-faced and
      spherical-faced nuts
E. (normative) Proof test for studs and bolts
F. (normative) Wedge test for bolt heads and stud
      collars
G. (normative) Torque/clamping-force test for flat-
      faced nut type fixings
H. (informative) Torque/clamping-force test for
      conical-faced and spherical-faced nut type fixings
Tables
1. Dimensions of flat-faced nuts
2. Dimensions of conical-faced nuts
3. Critical dimensions of studs
4. Critical dimensions of bolts
A.1 Dimensions of DIN spherical-faced (spherical collar)
      nuts (type A)
C.1 Proof test for flat-faced nuts
D.1 Proof test for conical-faced and spherical-faced
      nuts and all studs and bolts
F.1 Dimensions of wedges
F.2 Applied forces for the wedge test
G.1 Torque/clamping-force performance for flat-faced
      nut type fixings
H.1 Torque/clamping-force performance for conical-faced
      nut type fixings
H.2 Torque/clamping-force performance for spherical-
      faced nut type fixings
Figures
1. Dimensions of flat-faced nuts
2. Dimensions of conical-faced nuts
3. Critical dimensions of studs
4. Critical dimensions of bolts
A.1 Dimensions of DIN spherical faced (spherical collar)
      nuts (type A)
C.1 Proof test for flat-faced nuts
D.1 Adaptors for proof testing conical-faced and
      spherical-faced nuts and all studs and bolts
F.1 Wedge test for bolt-heads
F.2 Wedge test for stud-collars
G.1 Torque/clamping-force test for nuts, bolts and
      studs for flat-faced nut type fixings
H.1 Torque/clamping force test for nuts, bolts and
      studs for conical-faced and spherical-faced nut
      type fixings
List of references

Dimensional, material and performance requirements.

This Section of BS AU 50-2 specifies dimensions and performance requirements for a range of sizes of wheel and hub nuts, bolts, and studs for road vehicles. The range of sizes covered is normally used on heavy commercial vehicles, but if used on other types of vehicle the requirements of this standard are still applicable.

This standard does not cover back-nuts which are used to secure certain types of stud to wheel-hubs but it does cover that part of the stud on which the back-nut fits.

The standard is applicable to fasteners for spigot-located wheels employing 18 mm, 20 mm, 22 mm, and 24 mm studs with hexagonal nuts fitted with flat-seating, captive washers (type A mounting), cone-fixings of 18 mm, 7/8 in British Standard Fine (BSF), and 1 in BSF sizes (type B mounting), and spherical-faced nuts for 18 mm, 20 mm and 22 mm sizes.

NOTE Mounting types A and B are defined in BS AU 50-2.2. BSF threads are specified in BS 84, which is obsolescent, and such threads should be used only for replacement components for existing vehicles. Spherical-faced nuts are specified in DIN 74361 and dimensional details are given in Annex A.

In addition to the definitive requirements, this standard also requires the items listed in 3.4 to be documented. For compliance with this standard, both the definitive requirements and the documented items have to be satisfied.