4140 Heat Treated
 | 4140 Heat Treated is a quenched and tempered
chrome-moly steel, typically supplied at 262-321 Brinell. |
| 4140 Heat Treated is used in applications
requiring good machinablility, good tensile strength, and where parts would be subject to
unacceptable distortion if heat treated after machining. |
| Heat Treatment:
 | Stress Relief:
 | Heat 4140 Ph slowly and uniformly to 900*F.
|
| Allow piece to soak 1 hour per inch of section
thickness. |
| Air or furnace-cool to room temperature. |
|
| Annealing:
| Prior to rehardeing, Anneal 4140PH at
1450°F/1550°F for 4 hours |
| Cool Slowly (50°F/hr) to 1200°F, then air
cool. |
|
| Hardening:
| For higher Strength, per-heat to 1250°F for
one hour |
| Heat to 1525°F/1625°F, Soak for 30 minutes
after steel is at temperature. |
|
| Tempering:
| Temper 1 hour/inch of section thickness to
desired hardenss. Refer to the following tempering chart. |
|
|
Tempering Temperature, °F |
Hardness, Rc |
| 400 |
42 |
| 500 |
41 |
| 600 |
40 |
| 700 |
39 |
| 800 |
37 |
| 900 |
36 |
| 1000 |
34 |
| 1100 |
29 |
| 1200 |
25 |
Average Physical Properties - Heat Treated One inch section - Heated to 1525°F - Oil
Quenched
| Draw |
Tensile
Strength, PSI |
Yield
Point, PSI |
Elong.
2" |
Reduction
of Area |
Rockwell
C |
Brinell |
| 800° F |
200,000 |
180,000 |
14% |
50% |
45 |
429 |
| 1000° F |
165,000 |
150,000 |
17% |
54% |
36 |
341 |
| 1200°F |
135,000 |
106,000 |
20% |
60% |
29 |
277 |
Physical Properties - Test results on sections heat treated in .540" rd.
and tested in .505" rd x 2" long. Heated to 1550°F- Oil Quenched.
| Draw |
Tensile Strength PSI |
Yield Point, PSI |
Elong. 2" |
Reduction of Area |
Brinell |
| 600°F |
225,000 |
207,000 |
10% |
42% |
444 |
| 800°F |
180,000 |
164,000 |
13% |
49% |
363 |
| 1000°F |
145,000 |
128,000 |
19% |
58% |
293 |
| 1200°F |
125,000 |
105,000 |
24% |
68% |
255 |
| Hot Rolled Annealed |
90,000 |
63,000 |
28% |
58% |
183 |
| Annealed & Cold
Drawn |
110,000 |
100,000 |
17% |
45% |
212 |
| 4140 Heat Treated Machinability Rating -- Based in AISI 1212 as 100%
| Rating - 66 Surface Ft./Min. - 110 |
|
| Machining Data - Normalized and Tempered; Brinell 262 - 321 |
| Operation |
Depth of
Cut, in. |
High Speed Tooling |
Carbide Tooling |
| Speed,
fpm |
Feed,
in/rev. |
Speed,
fpm |
Feed,
in/rev. |
| Drilling |
1/8 1/4
1/2
1
2 |
45 45
45
45
45 |
.002 .004
.006
.009
.015 |
n/a n/a
n/a
n/a
n/a |
n/a n/a
n/a
n/a
n/a |
| Gun Drilling |
1/4 1/2
1
2 |
n/a n/a
n/a
n/a |
n/a n/a
n/a
n/a |
165 165
165
165 |
.005 .008
.0015
.002 |
| Single Point Turning |
.040 .150
.300 |
90 70
55 |
.007 .015
.020 |
440 340
270 |
.007 .015
.020 |
| Cut Off |
.062 .125
.250 |
55 55
55 |
.0013 .0016
.002 |
n/a n/a
n/a |
n/a n/a
n/a |
| Face Milling |
.040 .150
.300 |
105 85
65 |
.006* .009*
.012* |
485 375
290 |
.006* .008*
.010* |
| *Feed in inches per tooth |
| Size |
Draw |
Tensile
Strength, psi |
Yield
Point, psi |
Elong.
2" |
Reduction
of Area |
Brinell |
| 1 inch |
1000°F |
140,000 |
121,000 |
19% |
58% |
293 |
| 3 inch |
1000°F |
138,000 |
118,000 |
20% |
59% |
277 |
| 5 inch |
1000°F |
121,000 |
105,000 |
18% |
60% |
262 |
| 1 inch |
1200°F |
120,000 |
105,000 |
24% |
68% |
255 |
| 3 inch |
1200°F |
115,000 |
96,000 |
26 |
69 |
248 |
| 5 inch |
1200°F |
112,000 |
92,000 |
23 |
65 |
241 |
End-Quench
Jominy Hardenability - Tabulation of Band
Limits
| J" Distance |
Minimum |
Maximum |
| 1 |
60 |
53 |
| 2 |
60 |
53 |
| 3 |
60 |
52 |
| 4 |
59 |
51 |
| 5 |
59 |
51 |
| 6 |
58 |
50 |
| 7 |
58 |
48 |
| 8 |
57 |
47 |
| 9 |
57 |
45 |
| 10 |
56 |
42 |
| 11 |
56 |
40 |
| 12 |
55 |
39 |
| 13 |
55 |
38 |
| 14 |
54 |
37 |
| 16 |
53 |
35 |
| 18 |
52 |
34 |
| 20 |
51 |
33 |
| 24 |
48 |
32 |
| 28 |
46 |
31 |
| 32 |
44 |
30 |
|
