BS4466: 1989 Shape Codes

In April 2000 a new British Standard, BS8666 the ‘Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete’ was introduced, replacing BS 4466. Although BS4466 is superseded it is still used and is described below for reference purposes.

BS 4466 – Preferred Shapes

Method of measurement of
bending dimensions.
Total length of bar (L)
measured along centre line.
Method of measurement of
bending dimensions.
Total length of bar (L)
measured along centre line.
Shape Code 20
A
Shape Code 41
A+B+(C)
If angles with the horizontal
are 45° or less: see note 4.
Shape Code 32
A+h
Shape Code 43
A+2B+C+(E)
If angles with the horizontal are
45° or less: see note 4.
Shape Code 33
A+2h
Shape Code 51
A+(B)-½R-d

This formula is approximate, if R is minimum, use shape 37. If R is greater than 200mm, see note 2 to clause 10 BS 4466 1989.
Shape Code 34
A+n
Where the overall dimension of the bob is critical, use shape code 37.
Shape Code 61
12(A+B)+12d
Neither A nor B are to be less than 12d or 150mm, whichever is the greater, for grade 460 in sizes not exceeding 20 mm nor less than 14d for sizes of 25mm and over. Neither A nor B are to be less than 10d for grade 250 with a minimum value of A and B of 100mm. See note 3.
Shape Code 35
A+2n
Where the overall dimension of either
bob is critical, do not use this shape code.
Shape Code 62
A+(C)
If angle with horizontal is 45° or less.
See note 4.
Shape Code 37
A+(B)-½r-d
This formula is approximate. Where r is greater than the minimum value in table 3 BS 4466 1989, use shape code 51.
Shape Code 82
2A+3B+18d

If B is greater than 400+2d, see note 2 to clause 10 BS 4466 1989.
See note 3
Shape Code 38
A+B+(C)-r-2d

BS 4466 – Non Preferred Shapes

Method of measurement of
bending dimensions.
Total length of bar (L)
measured along centre line.
Method of measurement of
bending dimensions.
Total length of bar (L)
measured along centre line.
Shape Code 39
A+0.57B+(C)-1.57d
If B is greater than 400+2d, see note 2 to clause 10 BS 4466 1989
Shape Code 77
2A+B+20d
See note 3.
Shape Code 42
A+B+C+n
If angle with horizontal is 45° or less.
see note 4.
Shape Code 78
2A+B+C+3d
See note 3.
Shape Code 45
A+B+(C)-½r-d

If angle with horizontal is 45° or less.
see note 4.
Shape Code 79
2A+3B+10d

Neither A nor B shall be less than 12d or 150mm, whichever is the greater, for grade 460 in sizes not exceeding 20mm nor less than 14d for sizes of 25mm and over. Neither A nor B are to be less than 10d for grade 250 with a minimum value of A and B of 100mm. See note 3
Shape Code 49
A+B+(C)
If angle with horizontal is 45° or less. see note 4.
Shape Code 85
A+B+0.57 C+(D)-½r-2.57d

If C is greater than 400+2d see note 2 to clause 10 BS 4466 1989.
Shape Code 52
A+B+C+(D)-1½r-3d
Shape Code 87
C÷B π (A-d) (L<12m)
Where A is the external diameter of helix (in mm) B is the pitch of helix (in mm)C is the overall height of helix (in mm). Where B is greater than A/5 the formula does not apply. There shall be at least two full turns in the helix. Note, unless A is small relative to d, this shape is fabricated in a closed form and pulled to shape on site.
Shape Code 53
A+B+C+D+(E)-2r-4d
Custom Shape
Shape Code 99
All other shapes
To be calculated
A dimensional sketch shall be drawn out over schedule columns A to E. Every dimension that is to allow for the permissable deviations shall be indicated in parenthesis, otherwise the fabricator is free to choose which dimension shall allow for the tolerance.
Shape Code 54
A+B+(C)-r-2d
Shape Code 55
A+B+C+D+(E)-2r-4d
Shape Code 65
A
These bars will be supplied straight when the radius is greater than that given in table 5 of BS 4466 1989.

Notes

Note 1. r indicates the minimum value in the table 3 BS 4466 1989


Note 2. The dimensions in parenthesis are the free dimensions


Note 3. To avoid separate equations for each steel grade and bending radius, simplified total length formulae are used for shape codes 61, 77, 78, 79 and 82. These formulae are necessarily approximate.


Note 4. The length formula is approximate and when bending angles exceed 45° the length should be calculated more accurately allowing for the difference between the specified overall dimensions and the true length measured along the central axis of the bar or wire. When the bending angles approach 90°, it is preferable to specify shape code 99 with a fully dimensional sketch.


BAR MASS per linear metre (kg/m) :-
50mm: 15.413kg/m 40mm: 9.864kg/m 32mm: 6.313kg/m 25mm: 3.854kg/m 20mm: 2.466kg/m
16mm: 1.579kg/m 12mm: 0.888kg/m 10mm: 0.616kg/m 8mm: 0.395kg/m 6mm: 0.222kg/m
Table 3. Minimum former radii, bend and hook allowances
Bar Size Grade 250 bars complying with the requirements of BS 4449 (type and grade R) and BS 6744 type S Bar Size Grade 460 bars complying with the requirements of BS 4449 (type and grade T) and BS 6744 type S Fabric Size Sheet Fabric complying with the requirements of BS 4483
standard size 4.8m x 2.4m
d r+ n h d r+ n h d r+ n h
6 12 100 100 6 18 100 100 5 15 100 100
8 16 100 100 8 24 100 100 6 18 100 100
10 20 100 100 10 30 100 110 7 21 100 100
12 24 100 110 12 36 100 140 8 24 100 100
16 32 100 150 16 48 100 180 9 27 120 135
20 40 100 180 20 60 110 220 10 30 120 135
25 50 130 230 25 100 180 350 12 36 130 145
32 64 160 290 32 128 230 450
40 80 200 360 40 160 280 560
50 100 250 450 50 200 350 700

**The use of hooks as end anchorages is not normally necessary with deformed bars. It should be borne in mind that special precautions such as reducing the speed of bending or increasing the radius of bending may necessary in cold weather. For bending and rebending on site refer to BS 8110.

NOTE: These radii are the minimum radii of the formers for material complying with the relevant British standard. Certain design situations may call for larger radii and for these the recommendations in BS 8100 should be followed.

Radius of bending:- maximum values requiring bending

Bar Size 6 8 10 12 16 20 25 32 40
Radius (m) 2.5 2.75 3.5 4.25 7.5 14 30 43 58

N.B. Bars to be formed to a radius exceeding the above dimensions will be supplied straight.