| 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| Grade | Common application of nut | Ultimate tensile stress | Mimimum elongation on a gauge length 4√area See Note 3 |
Brinell hardness number. See Note 4 |
| A | Nuts for A, B, P and R bolts | tonf/in 28 min. |
per cent 10 14 |
HB10/3000 120/235 120/235 |
| P | Nuts for T bolts | 35 min. | 15 | 152/240 |
| R | Nuts for V bolts | 45 min. | 20 | 201/285 |
| T | Nuts for X bolts | 55 min. | 18 | 248/335 |
Note 1. B.S. 18, Methods for tensile testing of metals, noew specifies a guagew length of 5.65√area, but elongation values appropriate to this length are not yet available for the higher grades of steel. The Values in Column 4 have therefore been retained pending further information on the subject.
Note 2.
For nuts which are manufactured from the bar, the Brinell hardness numbers are given for guidance only and
are not part of the requirements of this standard. When nuts are manufactured by cold forming from around
wire, with or without subsequent heat-treatment, The Brinell hardness numbers apply as part of the
requirements of this standard.
The preparation of nuts to be tested and the method of tesing shall be in accordance with B.S. 240, '
method for brinell hardness test'. If Vickers or Rockwell methods are used, reference should be made t
B.S. 860, 'Table of approximate comparison of hardness scales', for appropriate values.
The test shall be made on the end faces of the nuts.