|
Standar for Bolt |
Grade |
Tension Stength |
Yield Strength |
Enlogation |
Length |
Hardness |
Head Marking |
|
|
ksi |
ksi |
% |
in. |
Brinell |
Rockwell B |
|||
|
A307 |
GR.A (hex head bolt) |
60min |
-- |
18 |
＜3*D |
121-241HRB |
69-100HRB |
|
|
≥3*D |
241max |
100max |
||||||
|
GR.C |
58-80 |
36 |
23 |
/ |
/ |
/ |
|
|
|
GR.B (heavy hex bolt) |
60-100 |
-- |
18 |
＜3*D |
121-212 |
69-95HRB |
|
|
|
≥3*D |
212max |
95max |
||||||
