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ASTM A574 TECHNICAL DATA

 

Order Socket Head Cap Screws Order Socket Shoulder Bolts

This specification covers the requirements for quenched and tempered alloy steel hexagon socket-head cap screws.

 

Technical Data: ASTM A574 Mechanical RequirementsASTM A574 Chemical RequirementsASTM A574 Tensile Requirements for Coarse Thread ScrewsASTM A574 Tensile Requirements for Fine Thread Screws ASTM A574 Chemical Composition

Mechanical Requirements

  ≤0.500 in. >0.500 in.
Property Nom. Dia. Nom. Dia.
Full-size screws:    
Tensile or wedge tensile strength, min, ksi 180 170
Proof load (stress), ksi 140 135
Product hardness:    
Rockwell (HRC) 39-45 37-45
Machined test specimen:    
Yield strength at 0.2% offset, min., ksi 153 153
Tensile strength, min., ksi 180 170
Elongation in 5D, min. 10% 10%
Reduction of area, min. 35% 35%

Chemical Requirements

  Composition, %
Element Heat Analysis   Product Analysis
Carbon, min 0.33   0.31
Phosphorus, max 0.035   0.040
Sulfur, max 0.040   0.045
Alloying elements   See 6.2  

Tensile Requirements for Coarse Thread Screws

Screw   
Dia (D), in.		 Threads/
in.		 Tensile
Load,
min, lbfA		 Stress
Area,
in.2 B

Proof Load

(Length Measurement Method),
min, lbfC
0.073 64 473 0.00263 368
0.086 56 666 0.00370 518
0.099 48 877 0.00487 682
0.112 40 1,090 0.00604 846
0.125 40 1,430 0.00796 1,110
0.138 32 1,640 0.00909 1,270
0.164 32 2,520 0.0140 1,960
0.190 24 3,150 0.0175 2,450
0.250 20 5,730 0.0318 4,450
0.3125 18 9,440 0.0524 7,340
0.375 16 13,900 0.0775 10,800
0.4375 14 19,100 0.1063 14,900
0.500 13 25,500 0.1419 19,900
0.625 11 38,400 0.226 30,500
0.750 10 56,800 0.334 45,100
0.875 9 78,500 0.462 62,400
1.000 8 103,000 0.606 81,800
1.125 7 129,000 0.763 103,000
1.250 7 165,000 0.969 131,000
1.375 6 196,000 1.155 156,000
1.500 6 239,000 1.405 190,000
1.750 5 323,000 1.90 256,000
2.000 41⁄2 425,000 2.50 338,000
2.250 41⁄2 552,000 3.25 439,000
2.500 4 680,000 4.00 540,000
2.750 4 838,000 4.93 666,000
3.000 4 1,010,000 5.97 806,000
3.250 4 1,210,000 7.10 958,000
3.500 4 1,420,000 8.33 1,120,000
3.750 4 1,640,000 9.66 1,300,000
4.000 4 1,880,000 11.08 1,500,000

A Values based on 180 ksi for 0.500 and smaller and 170 ksi for sizes larger than 0.500 in. and stress area in accordance with Footnote B.

B Stress areas based on Handbook H-28 (U.S. Department of Commerce) as follows:

As = 0.7854 [D - (0.9743/ n)]2

where:

As = stress area,

D = nominal screw size, and

n = threads/in.

C Values based on 140 ksi for 0.500 and smaller and 135 ksi for sizes larger than 0.500 in. and stress area in accordance with Footnote B.

Tensile Requirements for Fine Thread Screws

Screw   
Dia (D), in.		 Threads/
in.

Tensile
Load,

min, lbfA

 Stress
Area,
in.2 B

Proof Load

(Length Measurement Method),
min, lbfC
0.060 80 324 0.00180 252
0.073 72 500 0.00278 389
0.086 64 709 0.00394 552
0.099 56 941 0.00523 732
0.112 48 1,190 0.00661 925
0.125 44 1,490 0.00830 1,160
0.138 40 1,830 0.01015 1,420
0.164 36 2,650 0.01474 2,060
0.190 32 3,600 0.0200 2,800
0.250 28 6,500 0.0364 5,100
0.3125 24 10,400 0.0580 8,120
0.375 24 15,800 0.0878 12,300
0.4375 20 21,400 0.1187 16,600
0.500 20 28,800 0.1599 22,400
0.625 18 43,500 0.256 34,600
0.750 16 63,400 0.373 50,400
0.875 14 86,500 0.509 68,700
1.000 12 113,000 0.663 89,500
1.125 12 146,000 0.856 116,000
1.250 12 182,000 1.073 145,000
1.375 12 224,000 1.315 178,000
1.500 12 269,000 1.581 213,000

 

A Values based on 180 ksi for 0.500 and smaller and 170 ksi for sizes larger than 0.500 in. and stress area in accordance with Footnote B.

B Stress areas based on Handbook H-28 (U.S. Department of Commerce) as follows:

As = 0.7854 [D - (0.9743/ n)]2

where:

As = stress area,

D = nominal screw size, and

n = threads/in.

C Values based on 140 ksi for 0.500 and smaller and 135 ksi for sizes larger than 0.500 in. and stress area in accordance with Footnote B.

Chemical Composition

Grade
Designation		 4137 4142 4145 4340 8740 5137M 51B37M
UNS Number G41370 G41420 G41450 G43400 G87400 … …
Carbon:  
Heat Analysis 0.35-0.40 0.40-0.45 0.43-0.48 0.38-0.43 0.38-0.43 0.35-0.40 0.33-0.40
Product Analysis 0.33-0.42 0.38-0.47 0.41-0.50 0.36-0.45 0.36-0.45 0.33-0.42 0.31-0.42
Manganese:  
Heat Analysis 0.70-0.90 0.75-1.00 0.75-1.00 0.60-0.80 0.75-1.00 0.30-0.50 0.30-0.50
Product Analysis 0.67-0.93 0.71-1.04 0.71-1.04 0.57-0.83 0.71-1.04 0.27-0.53 0.27-0.53
Phosphorus, max:  
Heat Analysis 0.035 0.035 0.035 0.035 0.035 0.035 0.035
Product Analysis 0.040 0.040 0.040 0.040 0.040 0.040 0.040
Sulfur, max:  
Heat Analysis 0.040 0.040 0.040 0.040 0.040 0.040 0.040
Product Analysis 0.045 0.045 0.045 0.045 0.045 0.045 0.045
Silicon:  
Heat Analysis 0.15-0.35 0.15-0.35 0.15-0.35 0.15-0.35 0.15-0.35 0.15-0.35 0.15-0.35
Product Analysis 0.13-0.37 0.13-0.37 0.13-0.37 0.13-0.37 0.13-0.37 0.13-0.37 0.13-0.37
Nickel:  
Heat Analysis A A A 1.65-2.00 0.40-0.70 A A
Product Analysis ... ... ... 1.65-2.05 0.37-0.73 ... ...
Chromium:  
Heat Analysis 0.80-1.10 0.80-1.10 0.80-1.10 0.70-0.90 0.40-0.60 0.90-1.20 0.95-1.25
Product Analysis 0.75-1.15 0.75-1.15 0.75-1.15 0.67-0.93 0.37-0.63 0.85-1.25 0.90-1.30
Molybdenum:  
Heat Analysis 0.15-0.25 0.15-0.25 0.15-0.25 0.20-0.30 0.20-0.30 A A
Product Analysis 0.13-0.27 0.13-0.27 0.13-0.27 0.18-0.32 0.18-0.32 ... ...
Boron:  
Heat Analysis A A A A A A 0.0005-0.003
Product Analysis ... ... ... ... ... ... B

 

A Elements shown with an “A” are not applicable to that grade designation.
B Boron is not subject to product analysis.