British Standard Shape Codes
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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 Although BS4466 is superseded it is still used and is described below for reference purposes.
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)½Rd 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)½rd 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)r2d 
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)½rd 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)½r2.57d If C is greater than 400+2d see note 2 to clause 10 BS 4466 1989. 

Shape Code 52 A+B+C+(D)1½r3d 
Shape Code 87 C÷B π (Ad) (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)2r4d 
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)r2d 
Shape Code 55 A+B+C+D+(E)2r4d 

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. 
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.
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.