Heat Treatment Alloy Steel 40cr / 41cr4 / 5140 / ISO 8.8 Round Bars
Gr.8.8 round bars is the right material for Gr.8.8 threaded rods, anchor bolts, stud bolts , such high strength steel round bars, our processing usually have : Hot rolled, Hot rolled+Q&T, Cold drawn+Q&t, Peeled+Q&T and so on.
Our QT processing will be done thought the Medium frequency quenching furnace, which can gurantee the good straightness. so during the production of threading, it will have no hurt to the mould.
1.Materials equivalent grade
| ASTM |
JIS |
DIN |
BS |
NF
|
| 5140 |
SCr440 |
41Cr4(1.7035) |
530A40 |
42C4
|
2.SAE 5140 40Cr chemical composition
| Grade |
C |
Si |
Mn |
Cr |
P(≤) |
S(≤) |
| 40Cr |
0.37-0.44 |
0.17-0.37 |
0.5-0.8 |
0.8-1.0 |
0.035 |
0.035 |
| SAE 5140 |
0.38-0.43 |
0.15-0.35 |
0.7-0.9 |
0.7-0.9 |
0.035 |
0.035 |
| SCR440 |
0.38-0.43 |
0.15-0.35 |
0.6-0.9 |
0.9-1.2 |
0.035 |
0.035 |
| 40X |
0.36-0.44 |
0.17-0.37 |
0.5-0.8 |
0.8-1.1 |
0.035 |
0.035 |
| 41Cr4 |
0.38-0.45 |
0.1-0.4 |
0.6-0.9 |
0.9-1.2 |
0.035 |
0.035 |
3.Grade 8.8 properties:
| Grade |
Tensile Strength |
Yield Strength |
Elongation |
Reduction |
-40ºCAkv2/J |
Hardness |
| Mpa |
Mpa |
% |
% |
| 8.8 |
≥830 |
≥660 |
≥12 |
≥52 |
≥70 |
HRC23-34 |
Audited Supplier 
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